1.通过属性驱动式  
01.<form action="sys/login.action" method="post">    
02.    <input type="text" name="username">    
03.    <input type="submit" value="submit">    
04.</form>  


Action:直接通过get、set方法获取。 
01.public class sysAction extends ActionSupport{    
02.    private String username;    
03.   
04.    public String login() throws Exception {    
05.        System.out.println(username);    
06.        return SUCCESS;    
07.    }    
08.   
09.    public String getUsername() {    
10.        return username;    
11.    }    
12.    public void setUsername(String username) {    
13.        this.username= username;    
14.    }    
15.}     


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  
01.<form action="sys/login.action" method="post">    
02.    <input type="text" name="username">    
03.    <input type="submit" value="submit">    
04.</form>          




Action:必须实现getModel() 方法 
01.public class sysAction extends ActionSupport implements ModelDriven<User>{    
02.    private User user;    
03.   
04.    public String login() throws Exception {    
05.        System.out.println(getModel().getUsername());    
06.        return SUCCESS;    
07.    }    
08.   
09.    public User getModel() {    
10.        if (null == user) {    
11.            return user = new User();    
12.        }    
13.        return user;    
14.    }    
15.}     




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。 
01.<form action="sys/login.action" method="post">    
02.    <input type="text" name="user.username">    
03.    <input type="text" name="teacher.level">    
04.    <input type="submit" value="submit">    
05.</form>    




Action: 必须提供set方法 
01.public class sysAction extends ActionSupport{    
02.    private User user;    
03.    private Teacher teacher;    
04.   
05.    public String login() throws Exception {    
06.        System.out.println(user.getUsername());    
07.        System.out.println(teacher.getLevel());    
08.        return SUCCESS;    
09.    }    
10.   
11.    public void setUser(User user) {    
12.        this.user = user;    
13.    }    
14.    public void setTeacher(Teacher teacher) {    
15.        this.teacher = teacher;    
16.    }    
17.}