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();
}
}