HttpClient远程使用大全

一 HttpClient简介

1.1 概述

HttpClient只能以编程的方式通过其API用于传输和接受HTTP消息。主要实现功能：

实现了所有 HTTP 的方法（GET、POST、PUT、HEAD、DELETE、HEAD、OPTIONS 等）

支持 HTTPS 协议

支持代理服务器（Nginx等）等

支持自动（跳转）转向。

1.2 案例工程介绍

1.2.1 工程截图

请求端：16-spt-http-request-demo ：7000 响应端：16-spt-httppush-demo ：8082

1.2.2 引入依赖

    <!-- httpclient  -->
    <dependency>
      <groupId>org.apache.httpcomponents</groupId>
      <artifactId>httpclient</artifactId>
      <version>4.5.5</version>
    </dependency>
    <!-- fastjson -->
    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>fastjson</artifactId>
      <version>1.2.47</version>
    </dependency>

注：SpringBoot的基本依赖配置，这里就不再多说了

二实操实例Get方式

2.1 get无参数案例

1.消费者

@RestController
public class HttpClientController {
    @RequestMapping("/hc/api")
    public String getInfo() throws Exception {
// 获得Http客户端(可以理解为:你得先有一个浏览器;注意:实际上HttpClient与浏览器是不一样的)
        CloseableHttpClient httpClient = HttpClientBuilder.create().build();
        // 创建Get请求
        HttpGet httpGet = new HttpGet("http://localhost:8082/get/noparam");
         String result="";
        // 响应模型
        CloseableHttpResponse response = null;
        try {
            // 由客户端执行(发送)Get请求
            response = httpClient.execute(httpGet);
            // 从响应模型中获取响应实体
            HttpEntity responseEntity = response.getEntity();
            System.out.println("响应状态为:" + response.getStatusLine());
            if (responseEntity != null) {
                System.out.println("响应内容长度为:" + responseEntity.getContentLength());
                result=EntityUtils.toString(responseEntity);
                System.out.println("响应内容为:" + result);
            }


        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (ParseException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                // 释放资源
                if (httpClient != null) {
                    httpClient.close();
                }
                if (response != null) {
                    response.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return result;
    }
}

2.服务者

@RestController
public class HttpClientController {
    @RequestMapping("/get/noparam")
    public String doGetNoParam(){
          return "ok 123!";
    }
}

截图如下：

3.请求测试

2.2 get有参数：直接拼接URL

1.消费者

@RequestMapping("/hc/get/youcan")
    public String youcanOne() {
        // 获得Http客户端(可以理解为:你得先有一个浏览器;注意:实际上HttpClient与浏览器是不一样的)
        CloseableHttpClient httpClient = HttpClientBuilder.create().build();
        // 参数
        StringBuffer params = new StringBuffer();
        try {
            // 字符数据最好encoding以下;这样一来，某些特殊字符才能传过去(如:某人的名字就是“&”,不encoding的话,传不过去)
            params.append("name=" + URLEncoder.encode("zhangsan", "utf-8"));
            params.append("&");
            params.append("age=24");
        } catch (UnsupportedEncodingException e1) {
            e1.printStackTrace();
        }

        // 创建Get请求
        HttpGet httpGet = new HttpGet("http://localhost:8082/get/youparam1" + "?" + params);
        // 响应模型
        CloseableHttpResponse response = null;
        String result="";
        try {
            // 配置信息
            RequestConfig requestConfig = RequestConfig.custom()
                    // 设置连接超时时间(单位毫秒)
                    .setConnectTimeout(5000)
                    // 设置请求超时时间(单位毫秒)
                    .setConnectionRequestTimeout(5000)
                    // socket读写超时时间(单位毫秒)
                    .setSocketTimeout(5000)
                    // 设置是否允许重定向(默认为true)
                    .setRedirectsEnabled(true).build();

            // 将上面的配置信息 运用到这个Get请求里
            httpGet.setConfig(requestConfig);

            // 由客户端执行(发送)Get请求
            response = httpClient.execute(httpGet);

            // 从响应模型中获取响应实体
            HttpEntity responseEntity = response.getEntity();
            System.out.println("响应状态为:" + response.getStatusLine());
            if (responseEntity != null) {
                System.out.println("响应内容长度为:" + responseEntity.getContentLength());
                result=EntityUtils.toString(responseEntity);
                System.out.println("响应内容为:" + result);
            }
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (ParseException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                // 释放资源
                if (httpClient != null) {
                    httpClient.close();
                }
                if (response != null) {
                    response.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return result;
    }

2.提供者

    @RequestMapping("/get/youparam1")
    public String doGetYouParam(String name,Integer age){

        return "原来"+name+"都"+age+"岁";
    }

3.调用

2.3 get有参数：使用URI获得HttpGet

1.消费者

 @RequestMapping("/hc/get/youcan2")
    public String yooucan2() {
        // 获得Http客户端(可以理解为:你得先有一个浏览器;注意:实际上HttpClient与浏览器是不一样的)
        CloseableHttpClient httpClient = HttpClientBuilder.create().build();
        // 参数
        URI uri = null;
        try {
            // 将参数放入键值对类NameValuePair中,再放入集合中
            List<NameValuePair> params = new ArrayList<>();
            params.add(new BasicNameValuePair("name", "lisi"));
            params.add(new BasicNameValuePair("age", "18"));
            // 设置uri信息,并将参数集合放入uri;
            // 注:这里也支持一个键值对一个键值对地往里面放setParameter(String key, String value)
            uri = new URIBuilder().setScheme("http").setHost("localhost")
                    .setPort(8082).setPath("/get/youparam2")
                    .setParameters(params).build();
        } catch (URISyntaxException e1) {
            e1.printStackTrace();
        }
        // 创建Get请求
        HttpGet httpGet = new HttpGet(uri);
        // 响应模型
        CloseableHttpResponse response = null;
        String result="";
        try {
            // 配置信息
            RequestConfig requestConfig = RequestConfig.custom()
                    // 设置连接超时时间(单位毫秒)
                    .setConnectTimeout(5000)
                    // 设置请求超时时间(单位毫秒)
                    .setConnectionRequestTimeout(5000)
                    // socket读写超时时间(单位毫秒)
                    .setSocketTimeout(5000)
                    // 设置是否允许重定向(默认为true)
                    .setRedirectsEnabled(true).build();

            // 将上面的配置信息 运用到这个Get请求里
            httpGet.setConfig(requestConfig);

            // 由客户端执行(发送)Get请求
            response = httpClient.execute(httpGet);

            // 从响应模型中获取响应实体
            HttpEntity responseEntity = response.getEntity();
            System.out.println("响应状态为:" + response.getStatusLine());
            if (responseEntity != null) {
                System.out.println("响应内容长度为:" + responseEntity.getContentLength());
                result=EntityUtils.toString(responseEntity);
                System.out.println("响应内容为:" + result);
            }
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (ParseException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                // 释放资源
                if (httpClient != null) {
                    httpClient.close();
                }
                if (response != null) {
                    response.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return result;
    }

2.提供者

   @RequestMapping("/get/youparam2")
    public String doGetYouParam2(String name,Integer age){

        return "原来"+name+"都"+age+"岁";
    }

3.调试

三实操实例Post方式

3.1 post无参案例

1.生产者

 @RequestMapping("/hc/post/wucan")
    public String doPostTestOne() {

        // 获得Http客户端(可以理解为:你得先有一个浏览器;注意:实际上HttpClient与浏览器是不一样的)
        CloseableHttpClient httpClient = HttpClientBuilder.create().build();
        // 创建Post请求
        HttpPost httpPost = new HttpPost("http://localhost:8082/post/noparam");
        // 响应模型
        CloseableHttpResponse response = null;
        String result="";
        try {
            // 由客户端执行(发送)Post请求
            response = httpClient.execute(httpPost);
            // 从响应模型中获取响应实体
            HttpEntity responseEntity = response.getEntity();

            System.out.println("响应状态为:" + response.getStatusLine());
            if (responseEntity != null) {
                System.out.println("响应内容长度为:" + responseEntity.getContentLength());
                result=EntityUtils.toString(responseEntity);
                System.out.println("响应内容为:" + result);
            }
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (ParseException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                // 释放资源
                if (httpClient != null) {
                    httpClient.close();
                }
                if (response != null) {
                    response.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return result;
    }

2.消费者

  @RequestMapping("/post/noparam")
    public String doPostNoParam(){
        return "post  请求无参数  123!";
    }

3.调用

3.2 post有参案例

1.消费者

 @RequestMapping("/hc/post/youcan1")
    public String doPostTestFour() {

        // 获得Http客户端(可以理解为:你得先有一个浏览器;注意:实际上HttpClient与浏览器是不一样的)
        CloseableHttpClient httpClient = HttpClientBuilder.create().build();

        // 参数
        StringBuffer params = new StringBuffer();
        try {
            // 字符数据最好encoding以下;这样一来，某些特殊字符才能传过去(如:某人的名字就是“&”,不encoding的话,传不过去)
            params.append("name=" + URLEncoder.encode("zhangsan", "utf-8"));
            params.append("&");
            params.append("age=24");
        } catch (UnsupportedEncodingException e1) {
            e1.printStackTrace();
        }

        // 创建Post请求
        HttpPost httpPost = new HttpPost("http://localhost:8082//post/youparam1" + "?" + params);

        // 设置ContentType(注:如果只是传普通参数的话,ContentType不一定非要用application/json)
        httpPost.setHeader("Content-Type", "application/json;charset=utf8");

        // 响应模型
        CloseableHttpResponse response = null;
        String result="";
        try {
            // 由客户端执行(发送)Post请求
            response = httpClient.execute(httpPost);
            // 从响应模型中获取响应实体
            HttpEntity responseEntity = response.getEntity();

            System.out.println("响应状态为:" + response.getStatusLine());
            if (responseEntity != null) {
                System.out.println("响应内容长度为:" + responseEntity.getContentLength());
                result=EntityUtils.toString(responseEntity);
                System.out.println("响应内容为:" + result);
            }
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (ParseException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                // 释放资源
                if (httpClient != null) {
                    httpClient.close();
                }
                if (response != null) {
                    response.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return result;
    }

2.消费者

   @RequestMapping(value="/post/youparam1",method = RequestMethod.POST)
    public String doPostYouParam(String name,Integer age){

        return "原来"+name+"都"+age+"岁";
    }

3.调用

3.3 post有参案例2 通过对象映射

1.消费者

    @RequestMapping("/hc/post/youcan2")
    public String doPostTestTwo() {

        // 获得Http客户端(可以理解为:你得先有一个浏览器;注意:实际上HttpClient与浏览器是不一样的)
        CloseableHttpClient httpClient = HttpClientBuilder.create().build();

        // 创建Post请求
        HttpPost httpPost = new HttpPost("http://localhost:8082/post/youparam2");
        User user = new User();
        user.setName("潘晓婷");
        user.setAge(18);
        user.setGender("女");
        user.setMotto("姿势要优雅~");
        // 我这里利用阿里的fastjson，将Object转换为json字符串;
        // (需要导入com.alibaba.fastjson.JSON包)
        String jsonString = JSON.toJSONString(user);

        StringEntity entity = new StringEntity(jsonString, "UTF-8");

        // post请求是将参数放在请求体里面传过去的;这里将entity放入post请求体中
        httpPost.setEntity(entity);

        httpPost.setHeader("Content-Type", "application/json;charset=utf8");

        // 响应模型
        CloseableHttpResponse response = null;
        String result="";
        try {
            // 由客户端执行(发送)Post请求
            response = httpClient.execute(httpPost);
            // 从响应模型中获取响应实体
            HttpEntity responseEntity = response.getEntity();

            System.out.println("响应状态为:" + response.getStatusLine());
            if (responseEntity != null) {
                System.out.println("响应内容长度为:" + responseEntity.getContentLength());
                result=EntityUtils.toString(responseEntity);
                System.out.println("响应内容为:" + result);
            }
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (ParseException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                // 释放资源
                if (httpClient != null) {
                    httpClient.close();
                }
                if (response != null) {
                    response.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return result;
    }

2.请求者

   @RequestMapping(value="/post/youparam2",method = RequestMethod.POST)
    public String doPostYouParam(@RequestBody User u){
        return u.toString();
    }

3.调用

3.4 post有参案例3 通过对象映射+参数

1.消费者

 @RequestMapping("/hc/post/youcan3")
    public String doPostTestThree() {
        // 获得Http客户端(可以理解为:你得先有一个浏览器;注意:实际上HttpClient与浏览器是不一样的)
        CloseableHttpClient httpClient = HttpClientBuilder.create().build();

        // 创建Post请求
        // 参数
        URI uri = null;
        try {
            // 将参数放入键值对类NameValuePair中,再放入集合中
            List<NameValuePair> params = new ArrayList<>();
            params.add(new BasicNameValuePair("flag", "4"));
            params.add(new BasicNameValuePair("meaning", "这是什么鬼？"));
            // 设置uri信息,并将参数集合放入uri;
            // 注:这里也支持一个键值对一个键值对地往里面放setParameter(String key, String value)
            uri = new URIBuilder().setScheme("http").setHost("localhost").setPort(8082)
                    .setPath("/post/youparam3").setParameters(params).build();
        } catch (URISyntaxException e1) {
            e1.printStackTrace();
        }

        HttpPost httpPost = new HttpPost(uri);
        // HttpPost httpPost = new
        // HttpPost("http://localhost:12345/doPostControllerThree1");

        // 创建user参数
        User user = new User();
        user.setName("潘晓婷");
        user.setAge(18);
        user.setGender("女");
        user.setMotto("姿势要优雅~");

        // 将user对象转换为json字符串，并放入entity中
        StringEntity entity = new StringEntity(JSON.toJSONString(user), "UTF-8");

        // post请求是将参数放在请求体里面传过去的;这里将entity放入post请求体中
        httpPost.setEntity(entity);

        httpPost.setHeader("Content-Type", "application/json;charset=utf8");

        // 响应模型
        CloseableHttpResponse response = null;
        String result="";
        try {
            // 由客户端执行(发送)Post请求
            response = httpClient.execute(httpPost);
            // 从响应模型中获取响应实体
            HttpEntity responseEntity = response.getEntity();

            System.out.println("响应状态为:" + response.getStatusLine());
            if (responseEntity != null) {
                System.out.println("响应内容长度为:" + responseEntity.getContentLength());
                result=EntityUtils.toString(responseEntity);
                System.out.println("响应内容为:" + result);
            }
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (ParseException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                // 释放资源
                if (httpClient != null) {
                    httpClient.close();
                }
                if (response != null) {
                    response.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return result;
    }

2.生产者

    @RequestMapping(value="/post/youparam3",method = RequestMethod.POST)
    public String doPostYouParam(@RequestBody User u,Integer flag,String meaning){
        return u.toString()+" flag:"+flag+" meaning:"+meaning;
    }

3.调用