struts2 里面 action接收参数的三种方式 （转）

Java代码
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; 
    } 
}