Struts2 DomainModel、ModelDriven接收参数

一、DomainModel（域模型）

1、

应用场景：一般我们在struts2的action中接收参数通常是如下方式

package cn.orlion.user;

import com.opensymphony.xwork2.ActionSupport;

public class UserAction extends ActionSupport{
    
    private String username;
    
    private String password;
    
    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
    
    public String login(){
        
        System.out.println("username=" + username);
        System.out.println("password=" + password);
        
        return SUCCESS;
    }
}

这样会产生一个问题，当我们要获取的属性增多的话比如我们要加上age、sex、birthday…等等这样我们就要写巨多的getset方法。显然不可取，所以这时就可以用DomainModel来接收参数。

首先创建一个包：cn.orlion.model,然后创建一个User类，如下：

package cn.orlion.model;

public class User {
    
    private String username;
    
    private String password;
    
    private String age;

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getAge() {
        return age;
    }

    public void setAge(String age) {
        this.age = age;
    }
}

将上边的UserAction改成：

package cn.orlion.user;

import com.opensymphony.xwork2.ActionSupport;

import cn.orlion.model.User;

public class UserAction extends ActionSupport{
    
    private User user;
    
    public String login(){
        
        System.out.println("username=" + user.getUsername());
        System.out.println("password=" + user.getPassword());
        System.out.println("age=" + user.getAge());
        
        return SUCCESS;
    }
    
    public User getUser(){
        return user;
    }
    
    public void setUser(User user){
        this.user = user;
    }
}

当访问

http://localhost:8080/Struts2Demo1/user/login.action?user.username=1&user.password=2&user.age=3时就会在控制台打印出username=1

password=2

age=3

2、DTO（Data transfer Object）数据传输对象

上边的代码已经很好的解决了属性过多的问题，但仍然存在一个问题：当我们有一个属性不能添加到user中时，（比如注册页面通常会有一个确认密码的输入框用来接收passwordConfim）怎么办？这时就可以用DTO解决。由DTO生成域对象。

首先创建一个包cn.orlion.dto,然后创建一个类UserDTO如下：

package cn.orlion.dto;

public class UserDTO {
    
    private String username;
    
    private String password;
    
    private String passwordConfirm;
    
    private String age;
    
    public String getAge() {
        return age;
    }

    public void setAge(String age) {
        
        this.age = age;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getPasswordConfirm() {
        return passwordConfirm;
    }

    public void setPasswordConfirm(String passwordConfirm) {
        this.passwordConfirm = passwordConfirm;
    }
}

然后UserAction改为：

package cn.orlion.user;

import com.opensymphony.xwork2.ActionSupport;

import cn.orlion.dto.UserDTO;
import cn.orlion.model.User;

public class UserAction extends ActionSupport{
    
    private UserDTO userdto;

    public String login(){
        
        String password = userdto.getPassword();
        String passwordConfirm = userdto.getPasswordConfirm();
        
        System.out.println(password + "-" + passwordConfirm);
        
        if (!password.equals(passwordConfirm)) {
            System.out.println("两次输入密码不一致");
            return ERROR;
        }
        
        User user = new User();
        
        user.setUsername(userdto.getUsername());
        user.setPassword(userdto.getPassword());
        user.setAge(userdto.getAge());
        // 添加用户操作...
        
        return SUCCESS;
    }

    public UserDTO getUserdto() {
        return userdto;
    }

    public void setUserdto(UserDTO userdto) {
        this.userdto = userdto;
    }
}

访问http://localhost:8080/Struts2Demo1/user/login.action?userdto.username=1&userdto.password=2&userdto.passwordConfirm=2&userdto.age=3

这样就可以了。

二、ModelDriven

这种方式是让Action类实现ModelDriven接口：

package cn.orlion.user;

import com.opensymphony.xwork2.ModelDriven;

import cn.orlion.model.User;

public class UserAction implements ModelDriven<User>{
    
    private User user;

    public String login(){
        
        System.out.println(user.getUsername());
        
        System.out.println(user.getPassword());
        
        return "success";
    }
    
    public User getUser(){
        return user;
    }
    
    public void setUser(User user){
        this.user = user;
    }
    @Override
　　// 由于实现接口泛型指定为User所以返回值类型就不是Object而是User了。
    public User getModel() {
        
        return user;
    }
}

这样当访问http://localhost:8080/Struts2Demo/user/login.action?user.username=1&user.password=2控制台就会打印1、2。