Struts2接收請求參數1

Struts2 是MVC中的控制器（處理請求），所以在請求過程中，數據由Strutes解決;

接受請求參數的三種類型：屬性驅動、模型驅動、域驅動。（常用的是後兩種）

1）、屬性驅動：

Html代碼塊：

	<form action="loginAction" method="post">
		用戶名：<input type="text" name="username"><br>
		密 碼：<input type="password" name="password"><br>
		<input type="submit" value="Submit">
	</form>

Java代碼塊：

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";
	}
}

總結：直接在action的POJO類中聲明與表元素一致的屬性，並聲稱匹配的get/set方法，Strutes會自動提交到action中並直接給顯影的屬性賦值；

2）、模型驅動：

Html代碼塊：

	<form action="loginAction" method="post">
		用戶名：<input type="text" name="username"><br>
		密 碼：<input type="password" name="password"><br>
		<input type="submit" value="Submit">
	</form>

Action代碼塊：

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;
	}

總結：繼承ModelDriven接口，實現對應的getModel()方法；

3）、域驅動：

Html代碼塊：

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

Java代碼塊：

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 {	//一個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();
	}
}

總結：通常情況下，表單元素往往對應一個實體，實體又往往單獨放在實體層中，那麼此時就需要在action中放入實體對象作爲請求參數，域驅動的方式就是把實體中的對象作爲action的屬性；

public class User {	//一個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();
	}
}