[Struts2应用开发] JSON的应用

在日常的WEB应用开发过程中，前端常会涉及AJAX，而前台与后台的交互常用的数据格式就是JSON。

Struts2中使用JSON的方法方法如下：

Action:

如果action中的某些属性不需要在json里面出现，可以通过annotation ：@JSON(serialize=false)来标记改属性不需返回至JSON。

注意，如果某属性没有get方法，则该属性亦不会在返回JSON串里面出现。

import java.util.List;

import org.apache.struts2.json.annotations.JSON;
import com.opensymphony.xwork2.Action;

public class UsersAction extends BaseAction implements Action {

    private String userID;
    
    private String userName;
    
    private String userPwd;
    
    private String employeeName;
    
    private String userIDs;
        
    private UsersService usersService;
    
    private String queryString;
    
    private List<LS_PT_MST_USERS> userList;

    @JSON(serialize=false)
    public List<LS_PT_MST_USERS> getUserList() {
        return userList;
    }

    public void setUserList(List<LS_PT_MST_USERS> userList) {
        this.userList = userList;
    }

    public String getUserID() {
        return userID;
    }

    public void setUserID(String userID) {
        this.userID = userID;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public String getUserPwd() {
        return userPwd;
    }

    public void setUserPwd(String userPwd) {
        this.userPwd = userPwd;
    }

    public String getEmployeeName() {
        return employeeName;
    }

    public void setEmployeeName(String employeeName) {
        this.employeeName = employeeName;
    }

    public String getUserIDs() {
        return userIDs;
    }

    public void setUserIDs(String userIDs) {
        this.userIDs = userIDs;
    }

    @JSON(serialize=false)
    public UsersService getUsersService() {
        return usersService;
    }

    public void setUsersService(UsersService usersService) {
        this.usersService = usersService;
    }

    public String getQueryString() {
        return queryString;
    }

    public void setQueryString(String queryString) {
        this.queryString = queryString;
    }
    
    public String editUsers(){
        LS_PT_MST_USERS entity = usersService.get(Integer.parseInt(this.userID));
        this.userName = entity.getUSERNAME();
        this.userPwd = entity.getUSERPWD();
        this.employeeName = entity.getEMPLOYEENAME();
        return SUCCESS;
    }    
    
    @Override
    public String execute() throws Exception {
        // TODO Auto-generated method stub
        return null;
    }

}

struts.xml

在配置文件中，package必须继承json-default。在需要返回json的action定义中，result type=json。

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
    <package name="ptsystem" extends="json-default">
                
        <!-- ================== -->
        <!--    配置菜单Action   -->
        <!-- ================== -->
        <!-- 添加 -->
        <action name="add*" class="{1}Action" method="add{1}">
            <result name="success" type="redirectAction">show{1}</result>
        </action>
        <!-- 修改跳转 -->
        <action name="edit*" class="{1}Action" method="edit{1}">
            <result type="json"></result>
        </action>
        <!-- 更新 -->
        <action name="update*" class="{1}Action" method="update{1}">
            <result name="success" type="chain">show{1}</result>
        </action>
        <!-- 删除 -->
        <action name="delete*" class="{1}Action" method="delete{1}">
            <result name="success" type="chain">show{1}</result>
        </action>
        <!-- 列出所有 -->
        <action name="show*" class="{1}Action" method="show{1}">
            <result name="success">/setting/{1}List.jsp</result>
        </action>
        <!-- 搜索 -->
        <action name="query*" class="{1}Action" method="query{1}">
            <result name="success">/setting/{1}List.jsp</result>
        </action>
    </package>
    <!-- 上传附件定义 -->
    <constant name="struts.multipart.parser" value="jakarta">constant</constant>
    <constant name="struts.i18n.encoding" value="gbk" />
</struts>