最簡單的攔截器寫法 struts2

1、寫登入LoginAction

  [[封裝對象 user]]

public class User {
 private long id;
 private String username;
 private String password;
 private String email;
 private String phone;
 private String sex;
 private int age;
 public long getId() {
  return id;
 }
 public void setId(long id) {
  this.id = id;
 }
 public String getUsername() {
  System.out.println(username +"  username");
  return username;
 }
 public void setUsername(String username) {
  
  this.username = username;
 }
 public String getPassword() {
  System.out.println(password + "  password");
  return password;
 }
 public void setPassword(String password) {
  
  this.password = password;
 }
 public String getEmail() {
  return email;
 }
 public void setEmail(String email) {
  this.email = email;
 }
 public String getPhone() {
  return phone;
 }
 public void setPhone(String phone) {
  this.phone = phone;
 }
 public String getSex() {
  return sex;
 }
 public void setSex(String sex) {
  this.sex = sex;
 }
 public int getAge() {
  return age;
 }
 public void setAge(int age) {
  this.age = age;
 }
 
}

Action:

public class LoginAction extends ActionSupport{

 /**
  *
  */
 private static final long serialVersionUID = 1L;

 private User user;
 
 private String message;
 private String password;
 private String realpath;
 public String execute(){
  
  message = "hello world";
  return SUCCESS;
 }

 public User getUser() {
  System.out.println("！！！！！！！！！！！！！！！user.getUser()");
  return user;
 }

 public void setUser(User user) {
  System.out.println("user.setUser");
  if(user != null){
   System.out.println(user.getUsername() +" @@@@@@@@@@@@@@@@ "+"user.getUsername()");
  }
  this.user = user;
 }

 public String getMessage() {
  return message;
 }

 public void setMessage(String message) {
  this.message = message;
 }
 public String getPassword() {
  System.out.println("password bukaixin############################## "+password);
  return password;
 }

 public void setPassword(String password) {
  this.password = password;
 }

 public String getRealpath() {
  realpath="error";
  return realpath;
 }

 public void setRealpath(String realpath) {
  this.realpath = realpath;
 }
 
}

2、寫攔截器類

public class InterceptLogin extends AbstractInterceptor{

 private static final long serialVersionUID = 1L;
 

 @Override
 public String intercept(ActionInvocation invocation) throws Exception {
  String result = null;
  LoginAction action =(LoginAction)invocation.getAction();
  if(action != null){
   System.out.println("攔截開始    " +action.getMessage() + action.getUser() );
   System.out.println(action.toString()+"  fdfdfdfdfd");
  }
  if(action == null){
   System.out.println("action is null");
  }
  
  
  long date = System.currentTimeMillis();
//  System.out.println(date);
  if(action.getUser().getUsername().equals("1234")){
   result = invocation.invoke();
  }else{
   return "error";
  }
  long end = System.currentTimeMillis();
  
  System.out.println("攔截結束");
  System.out.println(end - date);
  
  
  System.out.println(result +"   " +action.getMessage() +"  "+ action.getUser());
  return result;
  
 }

3、寫設定檔

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
 <package name="default-qizheng" namespace="/aaa" extends="struts-default">
  <interceptors>
    <interceptor name="interceptLogin" class="com.qizheng.manager.util.InterceptLogin" />
    <interceptor-stack name="interLogin">
     <interceptor-ref name="defaultStack"></interceptor-ref>
     <interceptor-ref name="interceptLogin"></interceptor-ref>
    </interceptor-stack>
  </interceptors>
  
  <global-results>
   <result name="login">/login.jsp</result>
  </global-results>
  <action name="su" class="com.qizheng.manager.action.LoginAction">
   <result name="success" type="dispatcher">/success.jsp</result>
   <result name="error" type="dispatcher">/${realpath}.jsp</result>
   <interceptor-ref name="interLogin"></interceptor-ref>
   
  </action>
 </package>
</struts>

裡面有許多自己調試過的地方和嘗試不同方式的地方，有一定基礎的話，你應該懂的。裡面用到了一點ogal的ValueStack的知識，應該要學的。