• 路由：路由网关的基本构建块。它由ID，目标URI，谓词集合和过滤器集合定义。如果聚合谓词为true，则匹配路由。
• 谓词：这是 Java 8 Function谓词。输入类型为 Spring Framework ServerWebExchange。这使开发人员可以匹配HTTP请求中的任何内容，例如标头或参数。
• 过滤器：这些是使用特定工厂构造的实例 Spring Framework GatewayFilter。在此，可以在发送下游请求之前或之后修改请求和响应。

快捷方式配置由过滤器名称识别，后跟等号（=），后跟由逗号分隔的参数值（,）。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: after_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Cookie</span>=mycookie,mycookievalue</span></span></span>

先前的示例使用两个参数定义了Cookie Route Predicate Factory，即cookie名称mycookie和与mycookievalue相匹配的值。

完全扩展的参数看起来更像带有名称/值对的标准Yaml配置。通常，将有一个name键和一个args键。args键是用于配置谓词或过滤器的键值对的映射。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: after_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - name</span>: Cookie
<span style="color:#7f007f">          args</span>:
<span style="color:#7f007f">            name</span>: mycookie
<span style="color:#7f007f">            regexp</span>: mycookievalue</span></span></span>

这是上面显示的Cookie谓词的快捷方式配置的完整配置。

After路由谓词工厂采用一个参数，即datetime（这是Java ZonedDateTime）。该谓词匹配在当前日期时间之后发生的请求。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: after_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - After</span>=2017-01-20T17:42:47.789-07:00[America/Denver<span style="color:#7f0055"><strong>]</strong></span></span></span></span>

该路线与2017年1月20日17:42山区时间（丹佛）之后的所有请求匹配。

Before路由谓词工厂采用一个参数datetime（它是Java ZonedDateTime）。该谓词匹配当前日期时间之前发生的请求。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: before_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Before</span>=2017-01-20T17:42:47.789-07:00[America/Denver<span style="color:#7f0055"><strong>]</strong></span></span></span></span>

该路线与2017年1月20日17:42山区时间（丹佛）之前的所有请求匹配。

Between路由谓词工厂采用两个参数datetime1和datetime2，它们是Java ZonedDateTime对象。该谓词匹配在datetime1之后和datetime2之前发生的请求。datetime2参数必须在datetime1之后。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: between_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Between</span>=2017-01-20T17:42:47.789-07:00[America/Denver]<span style="color:#7f0055"><strong>,</strong></span> 2017-01-21T17:42:47.789-07:00[America/Denver<span style="color:#7f0055"><strong>]</strong></span></span></span></span>

该路线与2017年1月20日山区时间（丹佛）之后和2017年1月21日17:42山区时间（丹佛）之后的所有请求匹配。这对于维护时段可能很有用。

Cookie Route Predicate Factory采用两个参数，即cookie name和regexp（这是Java正则表达式）。该谓词匹配具有给定名称的cookie，并且值匹配正则表达式。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: cookie_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Cookie</span>=chocolate<span style="color:#7f0055"><strong>,</strong></span> ch.p</span></span></span>

此路由与请求匹配，具有一个名为chocolate的cookie，该cookie的值与ch.p正则表达式匹配。

Header Route Predicate Factory具有两个参数，标头name和regexp（这是Java正则表达式）。该谓词与具有给定名称的标头匹配，并且值与正则表达式匹配。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: header_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Header</span>=X-Request-Id<span style="color:#7f0055"><strong>,</strong></span> \d+</span></span></span>

如果请求具有名为X-Request-Id的标头，且其值与\d+正则表达式匹配（具有一个或多个数字的值），则此路由匹配。

Host Route Predicate Factory采用一个参数：主机名patterns的列表。模式是Ant样式的模式，以.作为分隔符。该谓词与匹配模式的Host头匹配。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: host_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Host</span>=**.somehost.org,**.anotherhost.org</span></span></span>

还支持URI模板变量，例如{sub}.myhost.org。

如果请求的Host标头的值为www.somehost.org或beta.somehost.org或www.anotherhost.org，则此路由将匹配。

该谓词提取URI模板变量（如上例中定义的sub）作为名称和值的映射，并使用在ServerWebExchangeUtils.URI_TEMPLATE_VARIABLES_ATTRIBUTE中定义的键将其放置在ServerWebExchange.getAttributes()中。这些值可供GatewayFilter工厂使用。

Method路由谓词工厂采用一个methods参数，该参数是一个或多个要匹配的HTTP方法。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: method_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Method</span>=GET,POST</span></span></span>

如果请求方法是GET或POST，则此路由将匹配。

Path路由谓词工厂采用两个参数：Spring PathMatcher patterns的列表和matchOptionalTrailingSeparator的可选标志。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: host_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Path</span>=/foo/{segment},/bar/{segment<span style="color:#7f0055"><strong>}</strong></span></span></span></span>

如果请求路径为例如/foo/1或/foo/bar或/bar/baz，则此路由将匹配。

该谓词提取URI模板变量（如以上示例中定义的segment）作为名称和值的映射，并使用在ServerWebExchangeUtils.URI_TEMPLATE_VARIABLES_ATTRIBUTE中定义的键将其放置在ServerWebExchange.getAttributes()中。这些值可供GatewayFilter工厂使用。

可以使用实用程序方法来简化对这些变量的访问。

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8">Map<String, String> uriVariables = ServerWebExchangeUtils.getPathPredicateVariables(exchange);

String segment = uriVariables.get(<span style="color:#2a00ff">"segment"</span>);</span></span></span>

Query Route Predicate Factory采用两个参数：必需的param和可选的regexp（这是Java正则表达式）。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: query_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Query</span>=baz</span></span></span>

如果请求包含baz查询参数，则此路由将匹配。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: query_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Query</span>=foo<span style="color:#7f0055"><strong>,</strong></span> ba.</span></span></span>

如果请求包含一个foo查询参数，其值与ba.正则表达式匹配，则此路由将匹配，因此bar和baz将匹配。

RemoteAddr路由谓词工厂采用sources的列表（最小大小1），它是CIDR表示法（IPv4或IPv6）字符串，例如192.168.0.1/16（其中192.168.0.1是IP地址， 16是子网掩码）。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: remoteaddr_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - RemoteAddr</span>=192.168.1.1/24</span></span></span>

如果请求的远程地址为192.168.1.10，则此路由将匹配。

Weight Route Predicate Factory接受两个参数group和weight（一个int）。权重是按组计算的。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: weight_high
<span style="color:#7f007f">        uri</span>: https://weighthigh.org
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Weight</span>=group1<span style="color:#7f0055"><strong>,</strong></span> 8
<span style="color:#7f007f">      - id</span>: weight_low
<span style="color:#7f007f">        uri</span>: https://weightlow.org
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Weight</span>=group1<span style="color:#7f0055"><strong>,</strong></span> 2</span></span></span>

此路由会将约80％的流量转发到https://weighthigh.org，并将约20％的流量转发到https://weighlow.org

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8">X-Forwarded-For: 0.0.0.1, 0.0.0.2, 0.0.0.3</span></span></span>

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8">RemoteAddressResolver resolver = XForwardedRemoteAddressResolver
    .maxTrustedIndex(1);

...

.route(<span style="color:#2a00ff">"direct-route"</span>,
    r -> r.remoteAddr(<span style="color:#2a00ff">"10.1.1.1"</span>, <span style="color:#2a00ff">"10.10.1.1/24"</span>)
        .uri(<span style="color:#2a00ff">"https://downstream1"</span>)
.route(<span style="color:#2a00ff">"proxied-route"</span>,
    r -> r.remoteAddr(resolver,  <span style="color:#2a00ff">"10.10.1.1"</span>, <span style="color:#2a00ff">"10.10.1.1/24"</span>)
        .uri(<span style="color:#2a00ff">"https://downstream2"</span>)
)</span></span></span>

AddRequestHeader GatewayFilter工厂采用name和value参数。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: add_request_header_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - AddRequestHeader</span>=X-Request-Foo<span style="color:#7f0055"><strong>,</strong></span> Bar</span></span></span>

这会将X-Request-Foo:Bar标头添加到所有匹配请求的下游请求标头中。

AddRequestHeader知道用于匹配路径或主机的URI变量。URI变量可用于该值，并将在运行时扩展。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: add_request_header_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Path</span>=/foo/{segment<span style="color:#7f0055"><strong>}</strong></span>
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - AddRequestHeader</span>=X-Request-Foo<span style="color:#7f0055"><strong>,</strong></span> Bar-{segment<span style="color:#7f0055"><strong>}</strong></span></span></span></span>

AddRequestParameter GatewayFilter工厂采用name和value参数。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: add_request_parameter_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - AddRequestParameter</span>=foo<span style="color:#7f0055"><strong>,</strong></span> bar</span></span></span>

这会将foo=bar添加到所有匹配请求的下游请求的查询字符串中。

AddRequestParameter知道用于匹配路径或主机的URI变量。URI变量可用于该值，并将在运行时扩展。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: add_request_parameter_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Host</span>: {segment}.myhost.org
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - AddRequestParameter</span>=foo<span style="color:#7f0055"><strong>,</strong></span> bar-{segment<span style="color:#7f0055"><strong>}</strong></span></span></span></span>

AddResponseHeader GatewayFilter工厂采用name和value参数。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: add_response_header_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - AddResponseHeader</span>=X-Response-Foo<span style="color:#7f0055"><strong>,</strong></span> Bar</span></span></span>

这会将X-Response-Foo:Bar标头添加到所有匹配请求的下游响应的标头中。

AddResponseHeader知道用于匹配路径或主机的URI变量。URI变量可用于该值，并将在运行时扩展。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: add_response_header_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Host</span>: {segment}.myhost.org
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - AddResponseHeader</span>=foo<span style="color:#7f0055"><strong>,</strong></span> bar-{segment<span style="color:#7f0055"><strong>}</strong></span></span></span></span>

DedupeResponseHeader GatewayFilter工厂采用name参数和可选的strategy参数。name可以包含标题名称列表，以空格分隔。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: dedupe_response_header_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - DedupeResponseHeader</span>=Access-Control-Allow-Credentials Access-Control-Allow-Origin</span></span></span>

在网关CORS逻辑和下游逻辑都将它们添加的情况下，这将删除Access-Control-Allow-Credentials和Access-Control-Allow-Origin响应头的重复值。

DedupeResponseHeader过滤器还接受可选的strategy参数。可接受的值为RETAIN_FIRST（默认值），RETAIN_LAST和RETAIN_UNIQUE。

Hystrix是Netflix的一个库，它实现了断路器模式。Hystrix GatewayFilter允许您将断路器引入网关路由，保护服务免受级联故障的影响，并允许您在下游故障的情况下提供后备响应。

要在您的项目中启用Hystrix GatewayFilters，请添加对Spring Cloud Netflix中的 spring-cloud-starter-netflix-hystrix的依赖。

Hystrix GatewayFilter工厂需要一个name参数，它是HystrixCommand的名称。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: hystrix_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - Hystrix</span>=myCommandName</span></span></span>

这会将其余过滤器包装在命令名称为myCommandName的HystrixCommand中。

Hystrix过滤器还可以接受可选的fallbackUri参数。当前，仅支持forward:计划的URI。如果调用了后备，则请求将被转发到与URI相匹配的控制器。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: hystrix_route
<span style="color:#7f007f">        uri</span>: lb://backing-service:8088
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Path</span>=/consumingserviceendpoint
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - name</span>: Hystrix
<span style="color:#7f007f">          args</span>:
<span style="color:#7f007f">            name</span>: fallbackcmd
<span style="color:#7f007f">            fallbackUri</span>: forward:/incaseoffailureusethis
<span style="color:#7f007f">        - RewritePath</span>=/consumingserviceendpoint<span style="color:#7f0055"><strong>,</strong></span> /backingserviceendpoint</span></span></span>

调用Hystrix后备广告时，它将转发到/incaseoffailureusethis URI。请注意，此示例还通过目标URI上的lb前缀演示了（可选）Spring Cloud Netflix Ribbon负载均衡。

主要方案是将fallbackUri用于网关应用程序中的内部控制器或处理程序。但是，也可以将请求重新路由到外部应用程序中的控制器或处理程序，如下所示：

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: ingredients
<span style="color:#7f007f">        uri</span>: lb://ingredients
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Path</span>=//ingredients/**
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - name</span>: Hystrix
<span style="color:#7f007f">          args</span>:
<span style="color:#7f007f">            name</span>: fetchIngredients
<span style="color:#7f007f">            fallbackUri</span>: forward:/fallback
<span style="color:#7f007f">      - id</span>: ingredients-fallback
<span style="color:#7f007f">        uri</span>: http://localhost:9994
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Path</span>=/fallback</span></span></span>

在此示例中，网关应用程序中没有fallback端点或处理程序，但是，另一个应用程序中没有fallback端点或处理程序，已在http://localhost:9994下注册。

如果将请求转发到后备，则Hystrix网关过滤器还会提供引起请求的Throwable。它作为ServerWebExchangeUtils.HYSTRIX_EXECUTION_EXCEPTION_ATTR属性添加到ServerWebExchange中，可以在网关应用程序中处理后备时使用。

对于外部控制器/处理程序方案，可以添加带有异常详细信息的标头。您可以在FallbackHeaders GatewayFilter Factory部分中找到有关它的更多信息。

Hystrix设置（例如超时）可以使用全局默认值进行配置，也可以使用Hystrix Wiki中所述的应用程序属性在逐条路由的基础上进行配置。

要为上述示例路由设置5秒超时，将使用以下配置：

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">hystrix.command.fallbackcmd.execution.isolation.thread.timeoutInMilliseconds</span>: 5000</span></span></span>

FallbackHeaders工厂允许您在转发到外部应用程序中的fallbackUri的请求的标头中添加Hystrix执行异常详细信息，例如以下情况：

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: ingredients
<span style="color:#7f007f">        uri</span>: lb://ingredients
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Path</span>=//ingredients/**
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - name</span>: Hystrix
<span style="color:#7f007f">          args</span>:
<span style="color:#7f007f">            name</span>: fetchIngredients
<span style="color:#7f007f">            fallbackUri</span>: forward:/fallback
<span style="color:#7f007f">      - id</span>: ingredients-fallback
<span style="color:#7f007f">        uri</span>: http://localhost:9994
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Path</span>=/fallback
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - name</span>: FallbackHeaders
<span style="color:#7f007f">          args</span>:
<span style="color:#7f007f">            executionExceptionTypeHeaderName</span>: Test-Header</span></span></span>

在此示例中，在运行HystrixCommand时发生执行异常之后，该请求将转发到fallback端点或运行在localhost:9994上的应用程序中的处理程序。具有异常类型，消息和-if available-根本原因异常类型和消息的标头将由FallbackHeaders过滤器添加到该请求。

通过设置下面列出的参数的值及其默认值，可以在配置中覆盖标头的名称：

您可以在Hystrix GatewayFilter工厂部分中找到有关Hystrix与Gateway一起工作的更多信息。

MapRequestHeader GatewayFilter要素采用'fromHeader'和'toHeader'参数。它创建一个新的命名标头（toHeader），并从传入的HTTP请求中从现有的命名标头（fromHeader）中提取值。如果输入标头不存在，则过滤器不起作用。如果新的命名标头已经存在，则将使用新值扩充其值。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: map_request_header_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - MapRequestHeader</span>=Bar<span style="color:#7f0055"><strong>,</strong></span> X-Request-Foo</span></span></span>

这会将X-Request-Foo:<values>标头添加到下游请求中，并带有来自传入的HTTP请求Bar标头的更新值。

PrefixPath GatewayFilter工厂采用单个prefix参数。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: prefixpath_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - PrefixPath</span>=/mypath</span></span></span>

这会将/mypath作为所有匹配请求的路径的前缀。因此，对/hello的请求将被发送到/mypath/hello。

PreserveHostHeader GatewayFilter工厂没有参数。该过滤器设置请求属性，路由过滤器将检查该请求属性以确定是否应发送原始主机头，而不是由HTTP客户端确定的主机头。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: preserve_host_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        filters</span>:
        - PreserveHostHeader</span></span></span>

RequestRateLimiter GatewayFilter工厂使用RateLimiter实现来确定是否允许继续当前请求。如果不是，则返回状态HTTP 429 - Too Many Requests（默认）。

该过滤器采用一个可选的keyResolver参数和特定于速率限制器的参数（请参见下文）。

keyResolver是实现KeyResolver接口的bean。在配置中，使用SpEL通过名称引用bean。#{@myKeyResolver}是引用名称为myKeyResolver的bean的SpEL表达式。

KeyResolver.java。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f0055"><strong>public</strong></span> <span style="color:#7f0055"><strong>interface</strong></span> KeyResolver {
	Mono<String> resolve(ServerWebExchange exchange);
}</span></span></span>

KeyResolver接口允许可插拔策略派生用于限制请求的密钥。在未来的里程碑中，将有一些KeyResolver实现。

KeyResolver的默认实现是PrincipalNameKeyResolver，它从ServerWebExchange检索Principal并调用Principal.getName()。

默认情况下，如果KeyResolver未找到密钥，则请求将被拒绝。可以使用spring.cloud.gateway.filter.request-rate-limiter.deny-empty-key（对或错）和spring.cloud.gateway.filter.request-rate-limiter.empty-key-status-code属性来调整此行为。

application.properties。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"># INVALID SHORTCUT CONFIGURATION
spring.cloud.gateway.routes[0].filters[0]=RequestRateLimiter=2, 2, #{@userkeyresolver}</span></span></span>

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: requestratelimiter_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - name</span>: RequestRateLimiter
<span style="color:#7f007f">          args</span>:
<span style="color:#7f007f">            redis-rate-limiter.replenishRate</span>: 10
<span style="color:#7f007f">            redis-rate-limiter.burstCapacity</span>: 20</span></span></span>

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><em><span style="color:gray">@Bean</span></em>
KeyResolver userKeyResolver() {
    <span style="color:#7f0055"><strong>return</strong></span> exchange -> Mono.just(exchange.getRequest().getQueryParams().getFirst(<span style="color:#2a00ff">"user"</span>));
}</span></span></span>

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: requestratelimiter_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - name</span>: RequestRateLimiter
<span style="color:#7f007f">          args</span>:
<span style="color:#7f007f">            rate-limiter</span>: <span style="color:#2a00ff">"#{@myRateLimiter}"</span>
<span style="color:#7f007f">            key-resolver</span>: <span style="color:#2a00ff">"#{@userKeyResolver}"</span></span></span></span>

RedirectTo GatewayFilter工厂采用一个status和一个url参数。状态应该是300系列重定向http代码，例如301。URL应该是有效的URL。这将是Location标头的值。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: prefixpath_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - RedirectTo</span>=302<span style="color:#7f0055"><strong>,</strong></span> https://acme.org</span></span></span>

这将发送带有Location:https://acme.org标头的状态302以执行重定向。

RemoveRequestHeader GatewayFilter工厂采用一个name参数。它是要删除的标题的名称。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: removerequestheader_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - RemoveRequestHeader</span>=X-Request-Foo</span></span></span>

这将删除X-Request-Foo标头，然后将其发送到下游。

RemoveResponseHeader GatewayFilter工厂采用一个name参数。它是要删除的标题的名称。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: removeresponseheader_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - RemoveResponseHeader</span>=X-Response-Foo</span></span></span>

这会将X-Response-Foo标头从响应中删除，然后将其返回到网关客户端。

要删除任何类型的敏感标头，应为可能需要的任何路由配置此过滤器。此外，您可以使用spring.cloud.gateway.default-filters一次配置此过滤器，并将其应用于所有路由。

RewritePath GatewayFilter工厂采用路径regexp参数和replacement参数。这使用Java正则表达式提供了一种灵活的方式来重写请求路径。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: rewritepath_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Path</span>=/foo/**
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - RewritePath</span>=/foo(?<segment>/?.*)<span style="color:#7f0055"><strong>,</strong></span> $\{segment<span style="color:#7f0055"><strong>}</strong></span></span></span></span>

对于/foo/bar的请求路径，这将在发出下游请求之前将路径设置为/bar。请注意，由于YAML规范，$\被$所取代。

RewriteLocationResponseHeader GatewayFilter工厂通常会修改Location响应标头的值，以摆脱后端特定的详细信息。它需要stripVersionMode，locationHeaderName，hostValue和protocolsRegex参数。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: rewritelocationresponseheader_route
<span style="color:#7f007f">        uri</span>: http://example.org
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - RewriteLocationResponseHeader</span>=AS_IN_REQUEST<span style="color:#7f0055"><strong>,</strong></span> Location<span style="color:#7f0055"><strong>,</strong></span> <span style="color:#7f0055"><strong>,</strong></span></span></span></span>

例如，对于请求POST https://api.example.com/some/object/name，Location响应标头值https://object-service.prod.example.net/v2/some/object/id将被重写为https://api.example.com/some/object/id。

参数stripVersionMode具有以下可能的值：NEVER_STRIP，AS_IN_REQUEST（默认），ALWAYS_STRIP。

参数hostValue（如果提供）将用于替换响应Location标头中的host:port部分。如果未提供，将使用Host请求标头的值。

参数protocolsRegex必须是有效的正则表达式String，协议名称将与之匹配。如果不匹配，过滤器将不执行任何操作。默认值为http|https|ftp|ftps。

RewriteResponseHeader GatewayFilter工厂采用name，regexp和replacement参数。它使用Java正则表达式以灵活的方式重写响应标头值。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: rewriteresponseheader_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - RewriteResponseHeader</span>=X-Response-Foo<span style="color:#7f0055"><strong>,</strong></span> <span style="color:#7f0055"><strong>,</strong></span> password=[^&]+<span style="color:#7f0055"><strong>,</strong></span> password=***</span></span></span>

对于标头值为/42?user=ford&password=omg!what&flag=true，在发出下游请求后它将被设置为/42?user=ford&password=***&flag=true。由于YAML规范，请使用$\来表示$。

在向下游转发呼叫之前，SaveSession GatewayFilter工厂强制执行WebSession::save操作。这在将Spring Session之类的内容用于惰性数据存储并且需要确保在进行转接呼叫之前已保存会话状态时特别有用。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: save_session
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Path</span>=/foo/**
<span style="color:#7f007f">        filters</span>:
        - SaveSession</span></span></span>

如果您将Spring Security与Spring Session 集成在一起，并且想要确保安全性详细信息已转发到远程进程，则至关重要。

SecureHeaders GatewayFilter Factory根据此博客文章的建议向响应中添加了许多标头。

要更改默认值，请在spring.cloud.gateway.filter.secure-headers名称空间中设置适当的属性：

要禁用默认值，请使用逗号分隔值设置属性spring.cloud.gateway.filter.secure-headers.disable。

例： spring.cloud.gateway.filter.secure-headers.disable=x-frame-options,strict-transport-security

SetPath GatewayFilter工厂采用路径template参数。通过允许路径的模板段，它提供了一种操作请求路径的简单方法。这将使用Spring Framework中的uri模板。允许多个匹配段。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: setpath_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Path</span>=/foo/{segment<span style="color:#7f0055"><strong>}</strong></span>
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - SetPath</span>=/{segment<span style="color:#7f0055"><strong>}</strong></span></span></span></span>

对于/foo/bar的请求路径，这将在发出下游请求之前将路径设置为/bar。

SetRequestHeader GatewayFilter工厂采用name和value参数。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: setrequestheader_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - SetRequestHeader</span>=X-Request-Foo<span style="color:#7f0055"><strong>,</strong></span> Bar</span></span></span>

该GatewayFilter用给定的名称替换所有标头，而不是添加。因此，如果下游服务器响应X-Request-Foo:1234，则将其替换为X-Request-Foo:Bar，下游服务将收到此信息。

SetRequestHeader知道用于匹配路径或主机的URI变量。URI变量可用于该值，并将在运行时扩展。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: setrequestheader_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Host</span>: {segment}.myhost.org
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - SetRequestHeader</span>=foo<span style="color:#7f0055"><strong>,</strong></span> bar-{segment<span style="color:#7f0055"><strong>}</strong></span></span></span></span>

SetResponseHeader GatewayFilter工厂采用name和value参数。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: setresponseheader_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - SetResponseHeader</span>=X-Response-Foo<span style="color:#7f0055"><strong>,</strong></span> Bar</span></span></span>

该GatewayFilter用给定的名称替换所有标头，而不是添加。因此，如果下游服务器以X-Response-Foo:1234响应，则将其替换为X-Response-Foo:Bar，这是网关客户端将收到的内容。

SetResponseHeader知道用于匹配路径或主机的URI变量。URI变量可用于该值，并将在运行时扩展。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: setresponseheader_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Host</span>: {segment}.myhost.org
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - SetResponseHeader</span>=foo<span style="color:#7f0055"><strong>,</strong></span> bar-{segment<span style="color:#7f0055"><strong>}</strong></span></span></span></span>

SetStatus GatewayFilter工厂采用单个status参数。它必须是有效的Spring HttpStatus。它可以是整数值404，也可以是枚举NOT_FOUND的字符串表示形式。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: setstatusstring_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - SetStatus</span>=BAD_REQUEST
<span style="color:#7f007f">      - id</span>: setstatusint_route
<span style="color:#7f007f">        uri</span>: https://example.org
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - SetStatus</span>=401</span></span></span>

无论哪种情况，响应的HTTP状态都将设置为401。

StripPrefix GatewayFilter工厂采用一个参数parts。parts参数指示在向下游发送请求之前，要从请求中剥离的路径中的零件数。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: nameRoot
<span style="color:#7f007f">        uri</span>: http://nameservice
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Path</span>=/name/**
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - StripPrefix</span>=2</span></span></span>

通过网关发送到/name/bar/foo的请求时，对nameservice的请求将类似于http://nameservice/foo。

Retry GatewayFilter Factory支持以下参数集：

如果启用了Retry过滤器，则会配置以下默认值：

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: retry_test
<span style="color:#7f007f">        uri</span>: http://localhost:8080/flakey
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Host</span>=*.retry.com
<span style="color:#7f007f">        filters</span>:
<span style="color:#7f007f">        - name</span>: Retry
<span style="color:#7f007f">          args</span>:
<span style="color:#7f007f">            retries</span>: 3
<span style="color:#7f007f">            statuses</span>: BAD_GATEWAY
<span style="color:#7f007f">            methods</span>: GET,POST
<span style="color:#7f007f">            backoff</span>:
<span style="color:#7f007f">              firstBackoff</span>: 10ms
<span style="color:#7f007f">              maxBackoff</span>: 50ms
<span style="color:#7f007f">              factor</span>: 2
<span style="color:#7f007f">              basedOnPreviousValue</span>: <span style="color:#7f0055"><strong>false</strong></span></span></span></span>

当请求大小大于允许的限制时，RequestSize GatewayFilter工厂可以限制请求到达下游服务。过滤器采用maxSize参数，该参数是请求的允许大小限制。maxSize is a `DataSize类型，因此值可以定义为数字，后跟可选的DataUnit后缀，例如'KB'或'MB'。字节的默认值为“ B”。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: request_size_route
<span style="color:#7f007f">      uri</span>: http://localhost:8080/upload
<span style="color:#7f007f">      predicates</span>:
<span style="color:#7f007f">      - Path</span>=/upload
<span style="color:#7f007f">      filters</span>:
<span style="color:#7f007f">      - name</span>: RequestSize
<span style="color:#7f007f">        args</span>:
<span style="color:#7f007f">          maxSize</span>: 5000000</span></span></span>

当请求因大小而被拒绝时，RequestSize GatewayFilter Factory将响应状态设置为413 Payload Too Large，并带有一个附加报头errorMessage。以下是此类errorMessage的示例。

errorMessage : Request size is larger than permissible limit. Request size is 6.0 MB where permissible limit is 5.0 MB

该过滤器被认为是BETA，API将来可能会更改

ModifyRequestBody过滤器可用于在网关向下游发送请求主体之前修改请求主体。

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><em><span style="color:gray">@Bean</span></em>
<span style="color:#7f0055"><strong>public</strong></span> RouteLocator routes(RouteLocatorBuilder builder) {
    <span style="color:#7f0055"><strong>return</strong></span> builder.routes()
        .route(<span style="color:#2a00ff">"rewrite_request_obj"</span>, r -> r.host(<span style="color:#2a00ff">"*.rewriterequestobj.org"</span>)
            .filters(f -> f.prefixPath(<span style="color:#2a00ff">"/httpbin"</span>)
                .modifyRequestBody(String.<span style="color:#7f0055"><strong>class</strong></span>, Hello.<span style="color:#7f0055"><strong>class</strong></span>, MediaType.APPLICATION_JSON_VALUE,
                    (exchange, s) -> <span style="color:#7f0055"><strong>return</strong></span> Mono.just(<span style="color:#7f0055"><strong>new</strong></span> Hello(s.toUpperCase())))).uri(uri))
        .build();
}

<span style="color:#7f0055"><strong>static</strong></span> <span style="color:#7f0055"><strong>class</strong></span> Hello {
    String message;

    <span style="color:#7f0055"><strong>public</strong></span> Hello() { }

    <span style="color:#7f0055"><strong>public</strong></span> Hello(String message) {
        <span style="color:#7f0055"><strong>this</strong></span>.message = message;
    }

    <span style="color:#7f0055"><strong>public</strong></span> String getMessage() {
        <span style="color:#7f0055"><strong>return</strong></span> message;
    }

    <span style="color:#7f0055"><strong>public</strong></span> <span style="color:#7f0055"><strong>void</strong></span> setMessage(String message) {
        <span style="color:#7f0055"><strong>this</strong></span>.message = message;
    }
}</span></span></span>

该过滤器被认为是BETA，API将来可能会更改

ModifyResponseBody过滤器可用于在将响应正文发送回客户端之前对其进行修改。

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><em><span style="color:gray">@Bean</span></em>
<span style="color:#7f0055"><strong>public</strong></span> RouteLocator routes(RouteLocatorBuilder builder) {
    <span style="color:#7f0055"><strong>return</strong></span> builder.routes()
        .route(<span style="color:#2a00ff">"rewrite_response_upper"</span>, r -> r.host(<span style="color:#2a00ff">"*.rewriteresponseupper.org"</span>)
            .filters(f -> f.prefixPath(<span style="color:#2a00ff">"/httpbin"</span>)
        		.modifyResponseBody(String.<span style="color:#7f0055"><strong>class</strong></span>, String.<span style="color:#7f0055"><strong>class</strong></span>,
        		    (exchange, s) -> Mono.just(s.toUpperCase()))).uri(uri)
        .build();
}</span></span></span>

如果您要添加过滤器并将其应用于所有路由，则可以使用spring.cloud.gateway.default-filters。该属性采用过滤器列表

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      default-filters</span>:
<span style="color:#7f007f">      - AddResponseHeader</span>=X-Response-Default-Foo<span style="color:#7f0055"><strong>,</strong></span> Default-Bar
<span style="color:#7f007f">      - PrefixPath</span>=/httpbin</span></span></span>

当有请求进入（并与路由匹配）时，过滤Web处理程序会将GlobalFilter的所有实例和GatewayFilter的所有特定于路由的实例添加到过滤器链中。该组合的过滤器链通过org.springframework.core.Ordered接口排序，可以通过实现getOrder()方法进行设置。

由于Spring Cloud网关区分执行过滤器逻辑的“前”阶段和“后”阶段（请参阅：工作原理），因此，具有最高优先级的过滤器将在“前”阶段中处于第一个阶段，在“阶段”中处于最后一个阶段。 “后期”阶段。

ExampleConfiguration.java。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><em><span style="color:gray">@Bean</span></em>
<span style="color:#7f0055"><strong>public</strong></span> GlobalFilter customFilter() {
    <span style="color:#7f0055"><strong>return</strong></span> <span style="color:#7f0055"><strong>new</strong></span> CustomGlobalFilter();
}

<span style="color:#7f0055"><strong>public</strong></span> <span style="color:#7f0055"><strong>class</strong></span> CustomGlobalFilter <span style="color:#7f0055"><strong>implements</strong></span> GlobalFilter, Ordered {

    <em><span style="color:gray">@Override</span></em>
    <span style="color:#7f0055"><strong>public</strong></span> Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        log.info(<span style="color:#2a00ff">"custom global filter"</span>);
        <span style="color:#7f0055"><strong>return</strong></span> chain.filter(exchange);
    }

    <em><span style="color:gray">@Override</span></em>
    <span style="color:#7f0055"><strong>public</strong></span> <span style="color:#7f0055"><strong>int</strong></span> getOrder() {
        <span style="color:#7f0055"><strong>return</strong></span> -1;
    }
}</span></span></span>

ForwardRoutingFilter在交换属性ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR中寻找URI。如果该网址具有forward方案（即forward:///localendpoint），它将使用Spring DispatcherHandler处理请求。请求URL的路径部分将被转发URL中的路径覆盖。未经修改的原始URL会附加到ServerWebExchangeUtils.GATEWAY_ORIGINAL_REQUEST_URL_ATTR属性中的列表中。

LoadBalancerClientFilter在交换属性ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR中寻找URI。如果该网址具有lb方案（即lb://myservice），它将使用Spring Cloud LoadBalancerClient将名称（上例中为myservice）解析为实际的主机和端口并替换相同属性中的URI。未经修改的原始URL会附加到ServerWebExchangeUtils.GATEWAY_ORIGINAL_REQUEST_URL_ATTR属性中的列表中。过滤器还将查看ServerWebExchangeUtils.GATEWAY_SCHEME_PREFIX_ATTR属性，以查看其是否等于lb，然后应用相同的规则。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: myRoute
<span style="color:#7f007f">        uri</span>: lb://service
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Path</span>=/service/**</span></span></span>

ReactiveLoadBalancerClientFilter在交换属性ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR中寻找URI。如果该网址具有lb方案（即lb://myservice），它将使用Spring Cloud ReactorLoadBalancer将名称（上例中为myservice）解析为实际的主机和端口并替换相同属性中的URI。未经修改的原始URL会附加到ServerWebExchangeUtils.GATEWAY_ORIGINAL_REQUEST_URL_ATTR属性中的列表中。过滤器还将查看ServerWebExchangeUtils.GATEWAY_SCHEME_PREFIX_ATTR属性，以查看其是否等于lb，然后应用相同的规则。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
<span style="color:#7f007f">      - id</span>: myRoute
<span style="color:#7f007f">        uri</span>: lb://service
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Path</span>=/service/**</span></span></span>

如果位于ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR交换属性中的URL具有http或https方案，则将运行Netty路由筛选器。它使用Netty HttpClient发出下游代理请求。响应将放在ServerWebExchangeUtils.CLIENT_RESPONSE_ATTR交换属性中，以供以后的过滤器使用。（有一个实验性WebClientHttpRoutingFilter，它执行相同的功能，但不需要净值）

如果ServerWebExchangeUtils.CLIENT_RESPONSE_ATTR交换属性中有净值HttpClientResponse，则NettyWriteResponseFilter将运行。它在所有其他筛选器完成后运行，并将代理响应写回到网关客户端响应。（有一个实验性WebClientWriteResponseFilter，它执行相同的功能，但不需要净值）

如果ServerWebExchangeUtils.GATEWAY_ROUTE_ATTR交换属性中存在Route对象，则RouteToRequestUrlFilter将运行。它基于请求URI创建一个新URI，但使用Route对象的URI属性进行了更新。新的URI放置在ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR交换属性中。

如果URI具有方案前缀（例如lb:ws://serviceid），则将从URI中剥离lb方案，并将其放在ServerWebExchangeUtils.GATEWAY_SCHEME_PREFIX_ATTR中，以供以后在过滤器链中使用。

如果位于ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR交换属性中的URL具有ws或wss方案，则Websocket路由筛选器将运行。它使用Spring Web套接字基础结构向下游转发Websocket请求。

通过在URI前面加上lb，例如lb:ws://serviceid，可以实现Websocket的负载均衡。

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      routes</span>:
      <span style="color:#3f5f5f"><em># SockJS route</em></span>
<span style="color:#7f007f">      - id</span>: websocket_sockjs_route
<span style="color:#7f007f">        uri</span>: http://localhost:3001
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Path</span>=/websocket/info/**
      <span style="color:#3f5f5f"><em># Normal Websocket route</em></span>
<span style="color:#7f007f">      - id</span>: websocket_route
<span style="color:#7f007f">        uri</span>: ws://localhost:3001
<span style="color:#7f007f">        predicates</span>:
<span style="color:#7f007f">        - Path</span>=/websocket/**</span></span></span>

要启用网关度量标准，请添加spring-boot-starter-actuator作为项目依赖项。然后，默认情况下，只要属性spring.cloud.gateway.metrics.enabled未设置为false，网关度量过滤器就会运行。该过滤器添加了一个带有以下标记的名为“ gateway.requests”的计时器指标：

然后可以从/actuator/metrics/gateway.requests 抓取 这些指标，并且可以轻松地将其与Prometheus集成以创建Grafana 仪表板。

网关路由ServerWebExchange后，它将通过在交换属性中添加gatewayAlreadyRouted将该交换标记为“已路由”。将请求标记为已路由后，其他路由筛选器将不会再次路由请求，实质上会跳过该筛选器。您可以使用多种便捷方法将交换标记为已路由，或者检查交换是否已路由。

Forwarded标头过滤器创建一个Forwarded标头，以发送到下游服务。它将当前请求的Host标头，方案和端口添加到任何现有的Forwarded标头中。

RemoveHopByHop标头过滤器从转发的请求中删除标头。被删除的头的默认列表来自IETF。

要更改此设置，请将spring.cloud.gateway.filter.remove-non-proxy-headers.headers属性设置为要删除的标头名称列表。

XForwarded标头过滤器创建各种X-Forwarded-*标头，以发送到下游服务。它使用Host头，当前请求的方案，端口和路径来创建各种头。

可以通过以下布尔属性（默认为true）控制单个标题的创建：

可以通过以下布尔属性（默认为true）控制追加多个标头：

网关维护一个客户端池，该客户端池用于路由到后端。通过https进行通信时，客户端会启动TLS握手。许多超时与此握手相关联。可以配置以下超时（显示默认值）：

application.yml。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring</span>:
<span style="color:#7f007f">  cloud</span>:
<span style="color:#7f007f">    gateway</span>:
<span style="color:#7f007f">      httpclient</span>:
<span style="color:#7f007f">        ssl</span>:
<span style="color:#7f007f">          handshake-timeout-millis</span>: 10000
<span style="color:#7f007f">          close-notify-flush-timeout-millis</span>: 3000
<span style="color:#7f007f">          close-notify-read-timeout-millis</span>: 0</span></span></span>

为了在Java中进行简单的配置，在RouteLocatorBuilder bean中定义了一个流畅的API。

GatewaySampleApplication.java。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#3f5f5f"><em>// static imports from GatewayFilters and RoutePredicates</em></span>
<em><span style="color:gray">@Bean</span></em>
<span style="color:#7f0055"><strong>public</strong></span> RouteLocator customRouteLocator(RouteLocatorBuilder builder, ThrottleGatewayFilterFactory throttle) {
    <span style="color:#7f0055"><strong>return</strong></span> builder.routes()
            .route(r -> r.host(<span style="color:#2a00ff">"**.abc.org"</span>).and().path(<span style="color:#2a00ff">"/image/png"</span>)
                .filters(f ->
                        f.addResponseHeader(<span style="color:#2a00ff">"X-TestHeader"</span>, <span style="color:#2a00ff">"foobar"</span>))
                .uri(<span style="color:#2a00ff">"http://httpbin.org:80"</span>)
            )
            .route(r -> r.path(<span style="color:#2a00ff">"/image/webp"</span>)
                .filters(f ->
                        f.addResponseHeader(<span style="color:#2a00ff">"X-AnotherHeader"</span>, <span style="color:#2a00ff">"baz"</span>))
                .uri(<span style="color:#2a00ff">"http://httpbin.org:80"</span>)
            )
            .route(r -> r.order(-1)
                .host(<span style="color:#2a00ff">"**.throttle.org"</span>).and().path(<span style="color:#2a00ff">"/get"</span>)
                .filters(f -> f.filter(throttle.apply(1,
                        1,
                        10,
                        TimeUnit.SECONDS)))
                .uri(<span style="color:#2a00ff">"http://httpbin.org:80"</span>)
            )
            .build();
}</span></span></span>

此样式还允许更多自定义谓词断言。RouteDefinitionLocator beans定义的谓词使用逻辑and进行组合。通过使用流畅的Java API，您可以在Predicate类上使用and()，or()和negate()运算符。

可以将网关配置为基于在DiscoveryClient兼容服务注册表中注册的服务来创建路由。

要启用此功能，请设置spring.cloud.gateway.discovery.locator.enabled=true并确保在类路径上启用了DiscoveryClient实现（例如Netflix Eureka，Consul或Zookeeper）。

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8">spring.cloud.gateway.discovery.locator.predicates[0].name: Path
spring.cloud.gateway.discovery.locator.predicates[0].args[pattern]: "'/'+serviceId+'/**'"
spring.cloud.gateway.discovery.locator.predicates[1].name: Host
spring.cloud.gateway.discovery.locator.predicates[1].args[pattern]: "'**.foo.com'"
spring.cloud.gateway.discovery.locator.filters[0].name: Hystrix
spring.cloud.gateway.discovery.locator.filters[0].args[name]: serviceId
spring.cloud.gateway.discovery.locator.filters[1].name: RewritePath
spring.cloud.gateway.discovery.locator.filters[1].args[regexp]: "'/' + serviceId + '/(?<remaining>.*)'"
spring.cloud.gateway.discovery.locator.filters[1].args[replacement]: "'/${remaining}'"</span></span></span>

一种新的，更详细的格式已添加到网关。这为每个路由增加了更多细节，从而允许查看与每个路由关联的谓词和过滤器以及任何可用的配置。

/actuator/gateway/routes

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f0055"><strong>[</strong></span>
  <span style="color:#7f0055"><strong>{</strong></span>
    <span style="color:#2a00ff">"predicate"</span>: <span style="color:#2a00ff">"(Hosts: [**.addrequestheader.org] && Paths: [/headers], match trailing slash: true)"</span><span style="color:#7f0055"><strong>,</strong></span>
    <span style="color:#2a00ff">"route_id"</span>: <span style="color:#2a00ff">"add_request_header_test"</span><span style="color:#7f0055"><strong>,</strong></span>
    <span style="color:#2a00ff">"filters"</span>: <span style="color:#7f0055"><strong>[</strong></span>
      <span style="color:#2a00ff">"[[AddResponseHeader X-Response-Default-Foo = 'Default-Bar'], order = 1]"</span><span style="color:#7f0055"><strong>,</strong></span>
      <span style="color:#2a00ff">"[[AddRequestHeader X-Request-Foo = 'Bar'], order = 1]"</span><span style="color:#7f0055"><strong>,</strong></span>
      <span style="color:#2a00ff">"[[PrefixPath prefix = '/httpbin'], order = 2]"</span>
    ]<span style="color:#7f0055"><strong>,</strong></span>
    <span style="color:#2a00ff">"uri"</span>: <span style="color:#2a00ff">"lb://testservice"</span><span style="color:#7f0055"><strong>,</strong></span>
    <span style="color:#2a00ff">"order"</span>: 0
  <span style="color:#7f0055"><strong>}</strong></span>
<span style="color:#7f0055"><strong>]</strong></span></span></span></span>

要启用此功能，请设置以下属性：

application.properties。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f007f">spring.cloud.gateway.actuator.verbose.enabled</span>=true</span></span></span>

在将来的版本中，该默认值为true。

要清除路由缓存，请向/actuator/gateway/refresh发出POST请求。该请求返回200，但没有响应主体。

要检索网关中定义的路由，请向/actuator/gateway/routes发出GET请求。产生的响应类似于以下内容：

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8">[{
  "route_id": "first_route",
  "route_object": {
    "predicate": "org.springframework.cloud.gateway.handler.predicate.PathRoutePredicateFactory$$Lambda$432/1736826640@1e9d7e7d",
    "filters": [
      "OrderedGatewayFilter{delegate=org.springframework.cloud.gateway.filter.factory.PreserveHostHeaderGatewayFilterFactory$$Lambda$436/674480275@6631ef72, order=0}"
    ]
  },
  "order": 0
},
{
  "route_id": "second_route",
  "route_object": {
    "predicate": "org.springframework.cloud.gateway.handler.predicate.PathRoutePredicateFactory$$Lambda$432/1736826640@cd8d298",
    "filters": []
  },
  "order": 0
}]</span></span></span>

该响应包含网关中定义的所有路由的详细信息。下表描述了响应的每个元素（即路线）的结构。

要检索有关一条路线的信息，请向/actuator/gateway/routes/{id}发送一个GET请求（例如/actuator/gateway/routes/first_route）。产生的响应类似于以下内容：

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8">{
  "id": "first_route",
  "predicates": [{
    "name": "Path",
    "args": {"_genkey_0":"/first"}
  }],
  "filters": [],
  "uri": "https://www.uri-destination.org",
  "order": 0
}]</span></span></span>

下表描述了响应的结构。

要创建路由，请使用指定路由字段的JSON正文向/gateway/routes/{id_route_to_create}发出POST请求（请参见上一小节）。

要删除路由，请向/gateway/routes/{id_route_to_delete}发出DELETE请求。

下表总结了Spring Cloud网关执行器端点。请注意，每个端点都有/actuator/gateway作为基本路径。

以下是一些有用的记录器，它们包含DEBUG和TRACE级别的有价值的故障排除信息。

Reactor Netty HttpClient和HttpServer可以启用窃听功能。与将reactor.netty日志级别设置为DEBUG或TRACE结合使用时，将允许记录信息，例如通过网络发送和接收的标头和正文。要启用此功能，请分别为HttpServer和HttpClient设置spring.cloud.gateway.httpserver.wiretap=true和/或spring.cloud.gateway.httpclient.wiretap=true。

为了编写路由谓词，您将需要实现RoutePredicateFactory。您可以扩展名为AbstractRoutePredicateFactory的抽象类。

MyRoutePredicateFactory.java。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f0055"><strong>public</strong></span> <span style="color:#7f0055"><strong>class</strong></span> MyRoutePredicateFactory <span style="color:#7f0055"><strong>extends</strong></span> AbstractRoutePredicateFactory<HeaderRoutePredicateFactory.Config> {

    <span style="color:#7f0055"><strong>public</strong></span> MyRoutePredicateFactory() {
        <span style="color:#7f0055"><strong>super</strong></span>(Config.<span style="color:#7f0055"><strong>class</strong></span>);
    }

    <em><span style="color:gray">@Override</span></em>
    <span style="color:#7f0055"><strong>public</strong></span> Predicate<ServerWebExchange> apply(Config config) {
        <span style="color:#3f5f5f"><em>// grab configuration from Config object</em></span>
        <span style="color:#7f0055"><strong>return</strong></span> exchange -> {
            <span style="color:#3f5f5f"><em>//grab the request</em></span>
            ServerHttpRequest request = exchange.getRequest();
            <span style="color:#3f5f5f"><em>//take information from the request to see if it</em></span>
            <span style="color:#3f5f5f"><em>//matches configuration.</em></span>
            <span style="color:#7f0055"><strong>return</strong></span> matches(config, request);
        };
    }

    <span style="color:#7f0055"><strong>public</strong></span> <span style="color:#7f0055"><strong>static</strong></span> <span style="color:#7f0055"><strong>class</strong></span> Config {
        <span style="color:#3f5f5f"><em>//Put the configuration properties for your filter here</em></span>
    }

}</span></span></span>

为了编写GatewayFilter，您将需要实现GatewayFilterFactory。您可以扩展名为AbstractGatewayFilterFactory的抽象类。

PreGatewayFilterFactory.java。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f0055"><strong>public</strong></span> <span style="color:#7f0055"><strong>class</strong></span> PreGatewayFilterFactory <span style="color:#7f0055"><strong>extends</strong></span> AbstractGatewayFilterFactory<PreGatewayFilterFactory.Config> {

	<span style="color:#7f0055"><strong>public</strong></span> PreGatewayFilterFactory() {
		<span style="color:#7f0055"><strong>super</strong></span>(Config.<span style="color:#7f0055"><strong>class</strong></span>);
	}

	<em><span style="color:gray">@Override</span></em>
	<span style="color:#7f0055"><strong>public</strong></span> GatewayFilter apply(Config config) {
		<span style="color:#3f5f5f"><em>// grab configuration from Config object</em></span>
		<span style="color:#7f0055"><strong>return</strong></span> (exchange, chain) -> {
			<span style="color:#3f5f5f"><em>//If you want to build a "pre" filter you need to manipulate the</em></span>
			<span style="color:#3f5f5f"><em>//request before calling chain.filter</em></span>
			ServerHttpRequest.Builder builder = exchange.getRequest().mutate();
			<span style="color:#3f5f5f"><em>//use builder to manipulate the request</em></span>
			<span style="color:#7f0055"><strong>return</strong></span> chain.filter(exchange.mutate().request(request).build());
		};
	}

	<span style="color:#7f0055"><strong>public</strong></span> <span style="color:#7f0055"><strong>static</strong></span> <span style="color:#7f0055"><strong>class</strong></span> Config {
		<span style="color:#3f5f5f"><em>//Put the configuration properties for your filter here</em></span>
	}

}</span></span></span>

PostGatewayFilterFactory.java。 

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><span style="color:#7f0055"><strong>public</strong></span> <span style="color:#7f0055"><strong>class</strong></span> PostGatewayFilterFactory <span style="color:#7f0055"><strong>extends</strong></span> AbstractGatewayFilterFactory<PostGatewayFilterFactory.Config> {

	<span style="color:#7f0055"><strong>public</strong></span> PostGatewayFilterFactory() {
		<span style="color:#7f0055"><strong>super</strong></span>(Config.<span style="color:#7f0055"><strong>class</strong></span>);
	}

	<em><span style="color:gray">@Override</span></em>
	<span style="color:#7f0055"><strong>public</strong></span> GatewayFilter apply(Config config) {
		<span style="color:#3f5f5f"><em>// grab configuration from Config object</em></span>
		<span style="color:#7f0055"><strong>return</strong></span> (exchange, chain) -> {
			<span style="color:#7f0055"><strong>return</strong></span> chain.filter(exchange).then(Mono.fromRunnable(() -> {
				ServerHttpResponse response = exchange.getResponse();
				<span style="color:#3f5f5f"><em>//Manipulate the response in some way</em></span>
			}));
		};
	}

	<span style="color:#7f0055"><strong>public</strong></span> <span style="color:#7f0055"><strong>static</strong></span> <span style="color:#7f0055"><strong>class</strong></span> Config {
		<span style="color:#3f5f5f"><em>//Put the configuration properties for your filter here</em></span>
	}

}</span></span></span>

为了编写自定义全局过滤器，您将需要实现GlobalFilter接口。这会将过滤器应用于所有请求。

如何分别设置全局前置和后置过滤器的示例

<span style="color:#333333"><span style="color:#000000"><span style="background-color:#f8f8f8"><em><span style="color:gray">@Bean</span></em>
<span style="color:#7f0055"><strong>public</strong></span> GlobalFilter customGlobalFilter() {
    <span style="color:#7f0055"><strong>return</strong></span> (exchange, chain) -> exchange.getPrincipal()
        .map(Principal::getName)
        .defaultIfEmpty(<span style="color:#2a00ff">"Default User"</span>)
        .map(userName -> {
          <span style="color:#3f5f5f"><em>//adds header to proxied request</em></span>
          exchange.getRequest().mutate().header(<span style="color:#2a00ff">"CUSTOM-REQUEST-HEADER"</span>, userName).build();
          <span style="color:#7f0055"><strong>return</strong></span> exchange;
        })
        .flatMap(chain::filter);
}

<em><span style="color:gray">@Bean</span></em>
<span style="color:#7f0055"><strong>public</strong></span> GlobalFilter customGlobalPostFilter() {
    <span style="color:#7f0055"><strong>return</strong></span> (exchange, chain) -> chain.filter(exchange)
        .then(Mono.just(exchange))
        .map(serverWebExchange -> {
          <span style="color:#3f5f5f"><em>//adds header to response</em></span>
          serverWebExchange.getResponse().getHeaders().set(<span style="color:#2a00ff">"CUSTOM-RESPONSE-HEADER"</span>,
              HttpStatus.OK.equals(serverWebExchange.getResponse().getStatusCode()) ? <span style="color:#2a00ff">"It worked"</span>: <span style="color:#2a00ff">"It did not work"</span>);
          <span style="color:#7f0055"><strong>return</strong></span> serverWebExchange;
        })
        .then();
}</span></span></span>