//1.创建一个UserBean
public class User {

    private String username;
    private String pwd;
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = user　　name;
    }
    public String getPwd() {
        return pwd;
    }
    public void setPwd(String pwd) {
        this.pwd = pwd;
    }
    @Override
    public String toString() {
        return "User [username=" + username + ", pwd=" + pwd + "]";
    }
}
public class UserAction1 {
    
    /*
     * 属性驱动-1
     *     创建对应的属性，名称和jsp页面传递过来的参数名称一致
     *     创建对应属性的get和set方法
     */
    private String username;
    private String pwd;
    
    public String add(){
        System.out.println("账号：" + username);
        System.out.println("密码：" + pwd);
        return "success";
    }

    public String getUsername() {
        return username;
    }

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

    public String getPwd() {
        return pwd;
    }

    public void setPwd(String pwd) {
        this.pwd = pwd;
    }
    
}
/**
 * 属性驱动-2
 * 封装为一个对象，jsp页面参数需要将name属性值设置为 【成员变    
 * 量.属性名称】的方式传递参数
 * @author think
 *
 */
public class UserAction2 {

    private User user;
    
    public String save(){
        System.out.println(user);
        return "success";
    }

    public User getUser() {
        return user;
    }

    public void setUser(User user) {
        this.user = user;
    }
}

/**
 * 模型驱动
 *     1.实现ModelDriven接口，泛型传入的是接收的数据
 *     2.创建成员变量，必须实例化model对象
 *     3.实现getModel方法，返回model对象
 *     
 * @author think
 *
 */
public class UserAction3 implements ModelDriven<User>{

    private User model = new User();
    
    public String update(){
        System.out.println(model);
        return "success";
    }
    
    @Override
    public User getModel() {
        return model;
    }

}