Struts2 Action接收表单参数

struts2 Action获取表单传值   
1.通过属性驱动式   
JSP:   
    <form action="sys/login.action" method="post">   
        <input type="text" name="username">   
        <input type="submit" value="submit">   
    </form>   
       
Action:直接通过get、set方法获取。   
  

public class sysAction extends ActionSupport{   
    private String username;   
  
    public String login() throws Exception {   
        System.out.println(username);   
        return SUCCESS;   
    }   
  
    public String getUsername() {   
        return username;   
    }   
    public void setUsername(String username) {   
        this.username= username;   
    }   
}   
       

2.模型驱动方式，必须要实现ModelDriven<T>接口。对于要传入多个model第二种方式不方便   
JSP:   
    <form action="sys/login.action" method="post">   
        <input type="text" name="username">   
        <input type="submit" value="submit">   
    </form>   
       
Action:必须实现getModel() 方法   
  

public class sysAction extends ActionSupport implements ModelDriven<User>{   
    private User user;   
  
    public String login() throws Exception {   
        System.out.println(getModel().getUsername());   
        return SUCCESS;   
    }   
  
    public User getModel() {   
        if (null == user) {   
            return user = new User();   
        }   
        return user;   
    }   
}   
       

3.第三种方式可以完全不实现ModelDriven<T>，也可使用多个model对象的属性。   
JSP:   
    <form action="sys/login.action" method="post">   
        <input type="text" name="user.username">   
        <input type="text" name="teacher.level">   
        <input type="submit" value="submit">   
    </form>   
       
Action: 必须提供set方法   
  

public class sysAction extends ActionSupport{   
    private User user;   
    private Teacher teacher;   
  
    public String login() throws Exception {   
        System.out.println(user.getUsername());   
        System.out.println(teacher.getLevel());   
        return SUCCESS;   
    }   
  
    public void setUser(User user) {   
        this.user = user;   
    }   
    public void setTeacher(Teacher teacher) {   
        this.teacher = teacher;   
    }   
}