原理:在新建页面中Session保存token随机码,当保存时验证,通过后删除,当再次点击保存时由于服务器端的Session中已经不存在了,所有无法验证通过。
注,如果是集群的方式,则需要将token放入到缓存中即可。
注解Token代码:
@Target(ElementType.METHOD)
@Retention (RetentionPolicy.RUNTIME)
public @interface Token {
boolean needSaveToken () default false ;
boolean needRemoveToken () default false ;
}
拦截器TokenInterceptor代码:
public class TokenInterceptor extends HandlerInterceptorAdapter {
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throwsException {
if (handler instanceof HandlerMethod) {
HandlerMethod handlerMethod = (HandlerMethod) handler;
Method method = handlerMethod.getMethod();
Token annotation = method.getAnnotation(Token. class );
if (annotation != null ) {
boolean needSaveSession = annotation.save();
if (needSaveSession) {
request.getSession( false ).setAttribute( "token" , UUID.randomUUID().toString());
}
boolean needRemoveSession = annotation.remove();
if (needRemoveSession) {
if (isRepeatSubmit(request)) {
return false ;
}
request.getSession( false ).removeAttribute( "token" );
}
}
return true ;
} else {
return super .preHandle(request, response, handler);
}
}
private boolean isRepeatSubmit(HttpServletRequest request) {
String serverToken = (String) request.getSession( false ).getAttribute( "token" );
if (serverToken == null ) {
return true ;
}
String clinetToken = request.getParameter( "token" );
if (clinetToken == null ) {
return true ;
}
if (!serverToken.equals(clinetToken)) {
return true ;
}
return false ;
}
}
然后在Spring MVC的配置文件里加入:
<!-- 拦截器配置 -->
< mvc:interceptors >
<!-- 配置Shiro拦截器,实现注册用户的注入 -->
< mvc:interceptor >
< mvc:mapping path = "/**" />
< bean class = "com.storezhang.video.shiro.ShiroInterceptor" />
</ mvc:interceptor >
<!-- 配置Token拦截器,防止用户重复提交数据 -->
< mvc:interceptor >
< mvc:mapping path = "/**" />
< bean class = "com.storezhang.web.spring.TokenInterceptor" />
</ mvc:interceptor >
</ mvc:interceptors >
相关代码已经注释,相信你能看懂。
关于这个方法的用法是:在需要生成token的controller上增加@Token(save=true),而在需要检查重复提交的controller上添加@Token(remove=true)就可以了。
另外,你需要在view里在form里增加下面代码:
< input type = "hidden" name = "token" value = "${token}" />
在相关方法中加入注解
@RequestMapping("/save")
@AvoidDuplicateSubmission(needRemoveToken = true)
public synchronized ModelAndView save(ExecutionUnit unit, HttpServletRequest request, HttpServletResponse response)
throws Exception {
@RequestMapping("/edit")
@AvoidDuplicateSubmission(needSaveToken = true)
public ModelAndView edit(Integer id, HttpServletRequest request) throws Exception {
已经完成了,去试试看你的数据还能重复提交了吧。