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;@Overridepublic 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;@Overridepublic 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;@Overridepublic 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loginif (!"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>