Struts2 JSON转换案例

使用Struts2的过程中，前端经常是异步请求后端的，这时Struts的的后端就需要把数据以JSON字符串格式返回给前端，以便前端可以显示正常的效果。下面演示如何在Struts2的后端应用把结果转换为JSON？

1 导入Struts2的JSON插件包

2 设计User类，用于封装数据

package com.yiidian.domain;
import java.io.Serializable;
/**
 * @author  一点教程(yiidian.com)
 */
public class User implements Serializable{
	private String name;
	private String password;
	private String email;
	private String phone;
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	public String getEmail() {
		return email;
	}
	public void setEmail(String email) {
		this.email = email;
	}
	public String getPhone() {
		return phone;
	}
	public void setPhone(String phone) {
		this.phone = phone;
	}
	
}

3 编写Action类，返回数据

package com.yiidian.action;
import java.util.ArrayList;
import java.util.List;

import com.opensymphony.xwork2.ActionSupport;
import com.yiidian.domain.User;
/**
 * Struts2转换后台数据为Json字符串
 * @author  一点教程(yiidian.com)
 */
public class Demo1Action extends ActionSupport{
	//这个userList需要转换为Json字符串格式输出到浏览器
	private List<User> userList;
	public List<User> getUserList() {
		return userList;
	}
	public void setUserList(List<User> userList) {
		this.userList = userList;
	}

	@Override
	public String execute() throws Exception {
		userList = new ArrayList<User>();
		for(int i = 1;i<=5;i++){
			User user = new User();
			user.setName("小明"+i);
			user.setPassword("123");
			user.setEmail("xiaoming"+i+"@yiidian.com");
			user.setPhone("13211112222");
			userList.add(user);
		}
		
		return SUCCESS;
	}
}

4 struts.xml继承json-default

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
	"-//Apache Software Foundation//DTD Struts Configuration 2.5//EN"
	"http://struts.apache.org/dtds/struts-2.5.dtd">
<struts>
    <!-- 必须继承json-default包，json-default包是在struts2-json-plugin-2.5.13.jar定义的 -->
	<package name="base" extends="json-default" namespace="/">
		<action name="demo1" class="com.yiidian.action.Demo1Action">
		    <!-- 类型必须是json -->
			<result type="json">
			    <!-- root代表输出的是ValueStack的数据 ，userList名称和Action的getUserList的属性名称一致-->
				<param name="root">userList</param>
			</result>
		</action>
	</package>	
</struts>

5 配置web.xml

<?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>ch04_07_struts2_json</display-name>
  <filter>
    <filter-name>struts2</filter-name>
    <filter-class>org.apache.struts2.dispatcher.filter.StrutsPrepareAndExecuteFilter</filter-class>
  </filter>
  <filter-mapping>
    <filter-name>struts2</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>
</web-app>