Spring MVC分页示例
分页用于在不同部分显示大量记录。在这种情况下,我们将在一页中显示10、20或50条记录。对于其余记录,我们提供链接。
我们可以在Spring MVC中简单地创建分页示例。在此分页示例中,我们使用MySQL数据库来获取记录。
创建表或导入SQL文件
在这里,我们已经在"测试"数据库中创建了" emp"表。 emp表具有三个字段: ID,名称和薪水。创建表并手动插入记录,或导入我们的SQL文件。
Spring MVC分页示例
1、将依赖项添加到pom.xml文件。
pom.xml
示例
<!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>5.1.1.RELEASE</version> </dependency> <!-- https://mvnrepository.com/artifact/org.apache.tomcat/tomcat-jasper --> <dependency> <groupId>org.apache.tomcat</groupId> <artifactId>tomcat-jasper</artifactId> <version>9.0.12</version> </dependency> <!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api --> <dependency> <groupId>javax.servlet</groupId> <artifactId>servlet-api</artifactId> <version>3.0-alpha-1</version> </dependency> <!-- https://mvnrepository.com/artifact/javax.servlet/jstl --> <dependency> <groupId>javax.servlet</groupId> <artifactId>jstl</artifactId> <version>1.2</version> </dependency> <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>8.0.11</version> </dependency> <!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>5.1.1.RELEASE</version> </dependency>
2、创建bean类
在这里,bean类包含对应于数据库中存在的字段的变量(以及setter和getter方法)。
Emp.java
示例
package com.nhooo.beans; public class Emp { private int id; private String name; private float salary; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public float getSalary() { return salary; } public void setSalary(float salary) { this.salary = salary; } }
3、创建控制器类
在控制器类中, @PathVariable 批注将方法参数与临时URL绑定在一起。例如:
示例
@RequestMapping(value="/viewemp/{pageid}")
在此处,{}括号包含临时值。
EmpController.java
示例
package com.nhooo.controllers; import java.util.List; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import com.nhooo.beans.Emp; import com.nhooo.dao.EmpDao; @Controller public class EmpController { @Autowired EmpDao dao; @RequestMapping(value="/viewemp/{pageid}") public String edit(@PathVariable int pageid,Model m){ int total=5; if(pageid==1){} else{ pageid=(pageid-1)*total+1; } System.out.println(pageid); List<Emp> list=dao.getEmployeesByPage(pageid,total); m.addAttribute("msg", list); return "viewemp"; } }
4、创建DAO类
让我们创建一个DAO类以访问数据库中所需的数据。
EmpDao.java
示例
package com.nhooo.dao; import java.sql.ResultSet; import java.sql.SQLException; import java.util.List; import org.springframework.jdbc.core.JdbcTemplate; import org.springframework.jdbc.core.RowMapper; import com.nhooo.beans.Emp; public class EmpDao { JdbcTemplate template; public void setTemplate(JdbcTemplate template) { this.template = template; } public List<Emp> getEmployeesByPage(int pageid,int total){ String sql="select * from emp limit "+(pageid-1)+","+total; return template.query(sql,new RowMapper<Emp>(){ public Emp mapRow(ResultSet rs, int row) throws SQLException { Emp e=new Emp(); e.setId(rs.getInt(1)); e.setName(rs.getString(2)); e.setSalary(rs.getfloat(3)); return e; } }); } }
5、在web.xml文件中提供控制器的条目
web.xml
示例
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0"> <display-name>SpringMVC</display-name> <servlet> <servlet-name>spring</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>spring</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> </web-app>
6、在xml文件中定义Bean
spring-servlet.xml
示例
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd"> <context:component-scan base-package="com.nhooo.controllers"></context:component-scan> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/WEB-INF/jsp/"></property> <property name="suffix" value=".jsp"></property> </bean> <bean id="ds" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="driverClassName" value="com.mysql.jdbc.Driver"></property> <property name="url" value="jdbc:mysql://localhost:3306/test"></property> <property name="username" value=""></property> <property name="password" value=""></property> </bean> <bean id="jt" class="org.springframework.jdbc.core.JdbcTemplate"> <property name="dataSource" ref="ds"></property> </bean> <bean id="dao" class="com.nhooo.dao.EmpDao"> <property name="template" ref="jt"></property> </bean> </beans>
7、创建请求的页面
index.jsp
示例
<!DOCTYPE html> <html> <body> <a href="viewemp/1">View Employees</a> </body> </html>
8、创建视图组件
viewemp.jsp
示例
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%> <!DOCTYPE html public "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <body> <h1>Employees List</h1> <table border="2" width="70%" cellpadding="2"> <tr><th>Id</th><th>Name</th><th>Salary</th></tr> <c:forEach var="emp" items="${msg}"> <tr> <td>${emp.id}</td> <td>${emp.name}</td> <td>${emp.salary}</td> </tr> </c:forEach> </table> <br/> <a href="/SpringMVCPaginationExample/viewemp/1">1</a> <a href="/SpringMVCPaginationExample/viewemp/2">2</a> <a href="/SpringMVCPaginationExample/viewemp/3">3</a> </body> </html>
输出: