Struts2接收参数的几种方式

一、用Action属性

在action里定义要接收的参数，并提供相应的set和get方法。

如：

public class LoginAction extends ActionSupport {
    private String username;
    private String password;
    
    //对应的get set方法
    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 execute() {
        // TODO Auto-generated method stub
        System.out.println("username = "+username);
        System.out.println("password = "+password);
        return SUCCESS;
    }
}

<form action="login" method="post">
        用户名:<input type="text" name="username"><br/>
        密&nbsp;码：<input type="password" name="password"><br/>
        <input type="submit" value="提交">
    </form>

二、使用DomainModel

如果Action中属性过多，则可以Model保存为一个对象，并提供get和set

Model类

public class User {
    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;
    }
}

Action类

public class LoginAction extends ActionSupport {
    private User user;
    public String execute() {
        // TODO Auto-generated method stub
        System.out.println("username = "+user.getUsername());
        System.out.println("password = "+user.getPassword());
        return SUCCESS;
    }
    public User getUser() {
        return user;
    }
    public void setUser(User user) {
        this.user = user;
    }
}

JSP

<form action="login" method="post">
        用户名:<input type="text" name="user.username"><br/>
        密&nbsp;码：<input type="password" name="user.password"><br/>
        <input type="submit" value="提交">
    </form>

三、使用ModelDriven（模型驱动）

使用模型驱动模式时，Acton必须实现ModelDriven接口，实现该接口则必须实现getModel()方法，该方法用于把Action和与之对应的Model实例关联起来。

Model类同DomainModel

Action类

public class LoginAction extends ActionSupport implements ModelDriven<User> {
    private User user = new User();   //需实例化
    public String execute() {
        // TODO Auto-generated method stub
        System.out.println("username = "+user.getUsername());
        System.out.println("password = "+user.getPassword());
        return SUCCESS;
    }
    public User getUser() {
        return user;
    }
    public void setUser(User user) {
        this.user = user;
    }
    public User getModel() {
        // TODO Auto-generated method stub
        return user;
    }
}

JSP

<form action="login" method="post">
        <!-- 属性可以为 对象.XXX 也可以直接为XXX  则前提Action中要自己实例化Model对象 -->
        用户名:<input type="text" name="user.username"><br/>
        密&nbsp;码：<input type="password" name="password"><br/>
        <input type="submit" value="提交">
    </form>

四、使用request接收参数

此方法和传统的JSP页面接收参数一样，用request.getParameter("")方法。