Struts2拦截器之使用拦截器模拟实现登陆校验

首先说明一下，该例子只是说明拦截器如何实现登陆校验，并不符合正常的一些逻辑，2个操作页面，登陆和注册，

要实现的功能，只有登陆的用户才能够在注册页面操作，如果直接访问注册页面点击提交按钮，页面返回到登陆页面。

直接上代码，登陆和注册的Action:

package cn.com.baiwen.action;

import java.util.Map;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;

public class LoginAction extends ActionSupport{

private static final long serialVersionUID = 1L;

private String username;

private String password;

@Override
public String execute() throws Exception {

if("hello".equals(username) & "world".equals(password)){

//将用户放入到session当中（模拟）
Map<String, Object> session = ActionContext.getContext().getSession();
session.put("user", "valid");

return SUCCESS;
}

return ERROR;
}

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;
}

}

package cn.com.baiwen.action;

import java.util.Date;

import com.opensymphony.xwork2.ActionSupport;

public class RegisterAction extends ActionSupport {

private static final long serialVersionUID = 1L;

private String username;

private String password;

private String repassword;

private int age;

private Date birthday;

private Date graduation;

@Override
public String execute() throws Exception {

return SUCCESS;
}

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 getRepassword() {
return repassword;
}

public void setRepassword(String repassword) {
this.repassword = repassword;
}

public int getAge() {
return age;
}

public void setAge(int age) {
this.age = age;
}

public Date getBirthday() {
return birthday;
}

public void setBirthday(Date birthday) {
this.birthday = birthday;
}

public Date getGraduation() {
return graduation;
}

public void setGraduation(Date graduation) {
this.graduation = graduation;
}

}

JSP页面代码就不展示了，不重要，主要还是介绍一下拦截器，上面loginAction中已经写明，登陆时验证通过只够会存放到session当中信息，那么拦截器就要验证session当中user是否为空，还有我们正常开发，肯定是所有的页面都要做这个验证的，那么拦截器肯定要拦截所有的方法访问，那么怎么判断我是在登陆操作呢，
// 获得访问名称

String actionName = invocation.getInvocationContext().getName();

拦截器代码：

package cn.com.baiwen.interceptor;

import java.util.Map;

import com.opensymphony.xwork2.Action;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.AbstractInterceptor;

public class AuthInterceptor extends AbstractInterceptor {

private static final long serialVersionUID = 1L;

@Override
public String intercept(ActionInvocation invocation) throws Exception {

// 获得访问名称
String actionName = invocation.getInvocationContext().getName();

Map<String, Object> session = invocation.getInvocationContext()
.getSession();

// 如果session中user为空，则跳转到login
if (!"login".equals(actionName) && session.get("user") == null) {
return Action.LOGIN;
}

return invocation.invoke();
}

}


接下来是配置文件:
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
"http://struts.apache.org/dtds/struts-2.3.dtd">

<struts>
<package name="struts" extends="struts-default">

<!-- 拦截器配置 -->
<interceptors>
<interceptor name="authInterceptor" class="cn.com.baiwen.interceptor.AuthInterceptor"></interceptor>

<interceptor-stack name="myStack">
<interceptor-ref name="authInterceptor"></interceptor-ref>
<interceptor-ref name="defaultStack"></interceptor-ref>
</interceptor-stack>
</interceptors>

<default-interceptor-ref name="myStack"></default-interceptor-ref>

<!-- 全局的结果跳转配置 -->
<global-results>
<result name="login" type="redirect">/login.jsp</result>
</global-results>

<action name="login" class="cn.com.baiwen.action.LoginAction">
<result name="success">/register.jsp</result>
<result name="error">/error.jsp</result>
</action>

<action name="register" class="cn.com.baiwen.action.RegisterAction">
<result name="success">/result.jsp</result>
<result name="input">/register.jsp</result>
</action>
</package>
</struts>