Struts2接收请求参数1

Struts2 是MVC中的控制器（处理请求），所以在请求过程中，数据由Strutes解决;

接受请求参数的三种类型：属性驱动、模型驱动、域驱动。（常用的是后两种）

1）、属性驱动：

Html代码块：

	<form action="loginAction" method="post">
		用户名：<input type="text" name="username"><br>
		密 码：<input type="password" name="password"><br>
		<input type="submit" value="Submit">
	</form>

Java代码块：

public class LoginAction {
	private String username;
	private String password;
	public String getUsername() {
		return username;
	}
	public void setUsername(String username) {
		this.username = username;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}

	public String execute(){
		System.out.println(username+password);
		return "success";
	}
}

总结：直接在action的POJO类中声明与表元素一致的属性，并声称匹配的get/set方法，Strutes会自动提交到action中并直接给显影的属性赋值；

2）、模型驱动：

Html代码块：

	<form action="loginAction" method="post">
		用户名：<input type="text" name="username"><br>
		密 码：<input type="password" name="password"><br>
		<input type="submit" value="Submit">
	</form>

Action代码块：

public class LoginAction implements ModelDriven<User>{
	private User user;
	public String execute(){
		System.out.println(this.user.getUsername()+this.user.getPassword());
		return "success";
	}

	@Override
	public User getModel() {
		if(this.user == null){
			user = new User();
		}
		return user;
	}

总结：继承ModelDriven接口，实现对应的getModel()方法；

3）、域驱动：

Html代码块：

	<form action="loginAction" method="post">
		用户名：<input type="text" name="user.username"><br>
		密 码：<input type="password" name="user.password"><br>
		<input type="submit" value="Submit">
	</form>

Java代码块：

public class LoginAction {
	private User user;
	public void setUser(User user) {
		this.user = user;
	}
	public User getUser() {
		return user;
	}
	
	public String execute(){
		System.out.println(user);
		return "success";
	}
}

public class User {	//一个JAVABEAN
	private String username;
	private String password;
	public String getUsername() {
		return username;
	}
	public void setUsername(String username) {
		this.username = username;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	public User(String username, String password) {
		super();
		this.username = username;
		this.password = password;
	}
	@Override
	public String toString() {
		return "User [username=" + username + ", password=" + password
				+ "]";
	}
	
	public User() {
		super();
	}
}

总结：通常情况下，表单元素往往对应一个实体，实体又往往单独放在实体层中，那么此时就需要在action中放入实体对象作为请求参数，域驱动的方式就是把实体中的对象作为action的属性；

public class User {	//一个JAVABEAN
	private String username;
	private String password;
	public String getUsername() {
		return username;
	}
	public void setUsername(String username) {
		this.username = username;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	public User(String username, String password) {
		super();
		this.username = username;
		this.password = password;
	}
	@Override
	public String toString() {
		return "User [username=" + username + ", password=" + password
				+ "]";
	}
	
	public User() {
		super();
	}
}