问题描述:
现在的网站在注册步骤中,由于后台要处理大量信息,造成响应变慢(测试机器性能差也是造成变慢的一个因素),在前端页面提交信息之前,等待后端响应,此时如果用户
再点一次提交按钮,后台会保存多份用户信息。为解决此问题,借鉴了struts2的token思路,在springmvc下实现token。
实现思路:
在springmvc配置文件中加入拦截器的配置,拦截两类请求,一类是到页面的,一类是提交表单的。当转到页面的请求到来时,生成token的名 字和token值,一份放到redis缓存中,一份放传给页面表单的隐藏域。(注:这里之所以使用redis缓存,是因为tomcat服务器是集群部署 的,要保证token的存储介质是全局线程安全的,而redis是单线程的)
当表单请求提交时,拦截器得到参数中的tokenName和token,然后到缓存中去取token值,如果能匹配上,请求就通过,不能匹配上就不 通过。这里的tokenName生成时也是随机的,每次请求都不一样。而从缓存中取token值时,会立即将其删除(删与读是原子的,无线程安全问题)。
实现方式:
TokenInterceptor.java
- package com.xxx.www.common.interceptor;
-
- import java.io.IOException;
- import java.util.HashMap;
- import java.util.Map;
- import javax.servlet.http.HttpServletRequest;
- import javax.servlet.http.HttpServletResponse;
- import org.apache.log4j.Logger;
- import org.springframework.beans.factory.annotation.Autowired;
- import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;
- import com.xxx.cache.redis.IRedisCacheClient;
- import com.xxx.common.utility.JsonUtil;
- import com.xxx.www.common.utils.TokenHelper;
-
- /**
- *
- * @see TokenHelper
- */
- public class TokenInterceptor extends HandlerInterceptorAdapter
- {
-
- private static Logger log = Logger.getLogger(TokenInterceptor.class);
- private static Map<String , String> viewUrls = new HashMap<String , String>();
- private static Map<String , String> actionUrls = new HashMap<String , String>();
- private Object clock = new Object();
-
- @Autowired
- private IRedisCacheClient redisCacheClient;
- static
- {
- viewUrls.put("/user/regc/brandregnamecard/", "GET");
- viewUrls.put("/user/regc/regnamecard/", "GET");
-
- actionUrls.put("/user/regc/brandregnamecard/", "POST");
- actionUrls.put("/user/regc/regnamecard/", "POST");
- }
- {
- TokenHelper.setRedisCacheClient(redisCacheClient);
- }
-
- /**
- * 拦截方法,添加or验证token
- */
- @Override
- public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception
- {
- String url = request.getRequestURI();
- String method = request.getMethod();
- if(viewUrls.keySet().contains(url) && ((viewUrls.get(url)) == null || viewUrls.get(url).equals(method)))
- {
- TokenHelper.setToken(request);
- return true;
- }
- else if(actionUrls.keySet().contains(url) && ((actionUrls.get(url)) == null || actionUrls.get(url).equals(method)))
- {
- log.debug("Intercepting invocation to check for valid transaction token.");
- return handleToken(request, response, handler);
- }
- return true;
- }
-
- protected boolean handleToken(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception
- {
- synchronized(clock)
- {
- if(!TokenHelper.validToken(request))
- {
- System.out.println("未通过验证...");
- return handleInvalidToken(request, response, handler);
- }
- }
- System.out.println("通过验证...");
- return handleValidToken(request, response, handler);
- }
-
- /**
- * 当出现一个非法令牌时调用
- */
- protected boolean handleInvalidToken(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception
- {
- Map<String , Object> data = new HashMap<String , Object>();
- data.put("flag", 0);
- data.put("msg", "请不要频繁操作!");
- writeMessageUtf8(response, data);
- return false;
- }
-
- /**
- * 当发现一个合法令牌时调用.
- */
- protected boolean handleValidToken(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception
- {
- return true;
- }
-
- private void writeMessageUtf8(HttpServletResponse response, Map<String , Object> json) throws IOException
- {
- try
- {
- response.setCharacterEncoding("UTF-8");
- response.getWriter().print(JsonUtil.toJson(json));
- }
- finally
- {
- response.getWriter().close();
- }
- }
-
- }
TokenHelper.java
- package com.xxx.www.common.utils;
-
- import java.math.BigInteger;
- import java.util.Map;
- import java.util.Random;
- import javax.servlet.http.HttpServletRequest;
- import org.apache.log4j.Logger;
- import com.xxx.cache.redis.IRedisCacheClient;
-
- /**
- * TokenHelper
- *
- */
- public class TokenHelper
- {
-
- /**
- * 保存token值的默认命名空间
- */
- public static final String TOKEN_NAMESPACE = "xxx.tokens";
-
- /**
- * 持有token名称的字段名
- */
- public static final String TOKEN_NAME_FIELD = "xxx.token.name";
- private static final Logger LOG = Logger.getLogger(TokenHelper.class);
- private static final Random RANDOM = new Random();
-
- private static IRedisCacheClient redisCacheClient;// 缓存调用,代替session,支持分布式
-
- public static void setRedisCacheClient(IRedisCacheClient redisCacheClient)
- {
- TokenHelper.redisCacheClient = redisCacheClient;
- }
-
- /**
- * 使用随机字串作为token名字保存token
- *
- * @param request
- * @return token
- */
- public static String setToken(HttpServletRequest request)
- {
- return setToken(request, generateGUID());
- }
-
- /**
- * 使用给定的字串作为token名字保存token
- *
- * @param request
- * @param tokenName
- * @return token
- */
- private static String setToken(HttpServletRequest request, String tokenName)
- {
- String token = generateGUID();
- setCacheToken(request, tokenName, token);
- return token;
- }
-
- /**
- * 保存一个给定名字和值的token
- *
- * @param request
- * @param tokenName
- * @param token
- */
- private static void setCacheToken(HttpServletRequest request, String tokenName, String token)
- {
- try
- {
- String tokenName0 = buildTokenCacheAttributeName(tokenName);
- redisCacheClient.listLpush(tokenName0, token);
- request.setAttribute(TOKEN_NAME_FIELD, tokenName);
- request.setAttribute(tokenName, token);
- }
- catch(IllegalStateException e)
- {
- String msg = "Error creating HttpSession due response is commited to client. You can use the CreateSessionInterceptor or create the HttpSession from your action before the result is rendered to the client: " + e.getMessage();
- LOG.error(msg, e);
- throw new IllegalArgumentException(msg);
- }
- }
-
- /**
- * 构建一个基于token名字的带有命名空间为前缀的token名字
- *
- * @param tokenName
- * @return the name space prefixed session token name
- */
- public static String buildTokenCacheAttributeName(String tokenName)
- {
- return TOKEN_NAMESPACE + "." + tokenName;
- }
-
- /**
- * 从请求域中获取给定token名字的token值
- *
- * @param tokenName
- * @return the token String or null, if the token could not be found
- */
- public static String getToken(HttpServletRequest request, String tokenName)
- {
- if(tokenName == null)
- {
- return null;
- }
- Map params = request.getParameterMap();
- String[] tokens = (String[]) (String[]) params.get(tokenName);
- String token;
- if((tokens == null) || (tokens.length < 1))
- {
- LOG.warn("Could not find token mapped to token name " + tokenName);
- return null;
- }
-
- token = tokens[0];
- return token;
- }
-
- /**
- * 从请求参数中获取token名字
- *
- * @return the token name found in the params, or null if it could not be found
- */
- public static String getTokenName(HttpServletRequest request)
- {
- Map params = request.getParameterMap();
-
- if(!params.containsKey(TOKEN_NAME_FIELD))
- {
- LOG.warn("Could not find token name in params.");
- return null;
- }
-
- String[] tokenNames = (String[]) params.get(TOKEN_NAME_FIELD);
- String tokenName;
-
- if((tokenNames == null) || (tokenNames.length < 1))
- {
- LOG.warn("Got a null or empty token name.");
- return null;
- }
-
- tokenName = tokenNames[0];
-
- return tokenName;
- }
-
- /**
- * 验证当前请求参数中的token是否合法,如果合法的token出现就会删除它,它不会再次成功合法的token
- *
- * @return 验证结果
- */
- public static boolean validToken(HttpServletRequest request)
- {
- String tokenName = getTokenName(request);
-
- if(tokenName == null)
- {
- LOG.debug("no token name found -> Invalid token ");
- return false;
- }
-
- String token = getToken(request, tokenName);
-
- if(token == null)
- {
- if(LOG.isDebugEnabled())
- {
- LOG.debug("no token found for token name " + tokenName + " -> Invalid token ");
- }
- return false;
- }
-
- String tokenCacheName = buildTokenCacheAttributeName(tokenName);
- String cacheToken = redisCacheClient.listLpop(tokenCacheName);
-
- if(!token.equals(cacheToken))
- {
- LOG.warn("xxx.internal.invalid.token Form token " + token + " does not match the session token " + cacheToken + ".");
- return false;
- }
-
- // remove the token so it won't be used again
-
- return true;
- }
-
- public static String generateGUID()
- {
- return new BigInteger(165, RANDOM).toString(36).toUpperCase();
- }
-
- }
spring-mvc.xml
- <!-- token拦截器-->
- <bean id="tokenInterceptor" class="com.xxx.www.common.interceptor.TokenInterceptor"></bean>
- <bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping">
- <property name="interceptors">
- <list>
- <ref bean="tokenInterceptor"/>
- </list>
- </property>
- </bean>
input.jsp 在form中加如下内容:
- <input type="hidden" name="<%=request.getAttribute("xxx.token.name") %>" value="<%=token %>"/>
-
- <input type="hidden" name="xxx.token.name" value="<%=request.getAttribute("xxx.token.name") %>"/>
当前这里也可以用类似于struts2的自定义标签来做。
另:公司域名做了隐藏,用xxx替换了。
http://blog.csdn.net/mylovepan/article/details/38894941
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