struts2总结四:Action与Form表单的交互

struts2 Action获取表单数据的方式有三种:1.通过属性驱动的方式。2.模型驱动方式。3.使用多个model对象的属性。

1.通过属性驱动式

首先在jsp里面编写form表单的代码如下:

    <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。代码如下:

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，Action类必须要实现ModelDriven<T>接口。对于要传入多个model第二种方式不方便

首先在jsp里面编写form表单的代码如下:

    <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,代码如下所示:

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。

首先在jsp里面编写form表单的代码如下:

 <form action="sys/login.action" method="post">
        <input type="text" name="username">
        <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;
    }
}