Redis实现分布式session功能的共享

最近项目设计集群&＃xff0c;实现了一下session的共享功能&＃xff0c;其原理是将session保存到分布式缓存数据库中如&＃xff1a;redis&＃xff0c; memcache等&＃xff0c;然后多个服务器tomcat
每次请求都通过NoSql数据库查询&＃xff0c;如果存在&＃xff0c;则获取值&＃xff1b;反之存放值。
我是通过redis来实现session的共享&＃xff0c;其主要有一下两种方法&＃xff1a;
1、通过tomcat服务器的拓展功能实现这种方式比较简单&＃xff0c;主要是通过继承session的ManagerBase类&＃xff0c;实现重写session相关的方法&＃xff0c;这种比较简单&＃xff0c;参考源码链接&＃xff08;http://download.csdn.net/detail/fengshizty/9417242&＃xff09;。
2、通过filter拦截request请求实现下面主要介绍这样实现方式&＃xff1a;&＃xff08;1&＃xff09;写HttpSessionWrapper实现HttpSession接口&＃xff0c;实现里面session相关的方法。&＃xff08;2&＃xff09;写HttpServletRequestWrapper继承javax.servlet.http.HttpServletRequestWrapper类&＃xff0c;重写对于session 相关的方法。&＃xff08;3&＃xff09;写SessionFilter拦截配置的请求url&＃xff0c;过去COOKIE中的sessionId&＃xff0c;如果为空&＃xff0c;对此次请求重写生成一个新的sessionId&＃xff0c;在sessionId构造新的HttpServletRequestWrapper对象。&＃xff08;4&＃xff09;写SessionService实现session到redis的保存和过去&＃xff0c;其key为sessionId&＃xff0c;value为session对于的Map。
3、代码实现&＃xff08;1&＃xff09;HttpSessionWrapper


/*** 创建时间&＃xff1a;2016年1月21日 下午7:55:41* * &＃64;author andy* &＃64;version 2.2*/public class HttpSessionWrapper implements HttpSession {private String sid &＃61; "";private HttpSession session;private HttpServletRequest request;private HttpServletResponse response;private Map map &＃61; null;private SessionService sessionService &＃61; (SessionService) SpringContextHolder.getBean("sessionService");public HttpSessionWrapper() {}public HttpSessionWrapper(HttpSession session) {this.session &＃61; session;}public HttpSessionWrapper(String sid, HttpSession session) {this(session);this.sid &＃61; sid;}public HttpSessionWrapper(String sid, HttpSession session,HttpServletRequest request, HttpServletResponse response) {this(sid, session);this.request &＃61; request;this.response &＃61; response;}private Map getSessionMap() {if (this.map &＃61;&＃61; null) {this.map &＃61; sessionService.getSession(this.sid);}return this.map;}&＃64;Overridepublic Object getAttribute(String name) {if (this.getSessionMap() !&＃61; null) {Object value &＃61; this.getSessionMap().get(name);return value;}return null;}&＃64;Overridepublic void setAttribute(String name, Object value) {this.getSessionMap().put(name, value);sessionService.saveSession(this.sid, this.getSessionMap());}&＃64;Overridepublic void invalidate() {this.getSessionMap().clear();sessionService.removeSession(this.sid);COOKIEUtil.removeCOOKIEValue(this.request,this.response, GlobalConstant.JSESSIONID);}&＃64;Overridepublic void removeAttribute(String name) {this.getSessionMap().remove(name);sessionService.saveSession(this.sid, this.getSessionMap()); }&＃64;Overridepublic Object getValue(String name) {return this.session.getValue(name);}&＃64;SuppressWarnings("unchecked")&＃64;Overridepublic Enumeration getAttributeNames() {return (new Enumerator(this.getSessionMap().keySet(), true));}&＃64;Overridepublic String[] getValueNames() {return this.session.getValueNames();}&＃64;Overridepublic void putValue(String name, Object value) {this.session.putValue(name, value);}&＃64;Overridepublic void removeValue(String name) {this.session.removeValue(name);}&＃64;Overridepublic long getCreationTime() {return this.session.getCreationTime();}&＃64;Overridepublic String getId() {return this.sid;}&＃64;Overridepublic long getLastAccessedTime() {return this.session.getLastAccessedTime();}&＃64;Overridepublic ServletContext getServletContext() {return this.session.getServletContext();}&＃64;Overridepublic void setMaxInactiveInterval(int interval) {this.session.setMaxInactiveInterval(interval);}&＃64;Overridepublic int getMaxInactiveInterval() {return this.session.getMaxInactiveInterval();}&＃64;Overridepublic HttpSessionContext getSessionContext() {return this.session.getSessionContext();}&＃64;Overridepublic boolean isNew() {return this.session.isNew();}}

&＃xff08;2&＃xff09;HttpServletRequestWrapper实现


/*** 创建时间&＃xff1a;2016年1月22日 下午7:52:29* * &＃64;author andy* &＃64;version 2.2*/public class HttpServletRequestWrapper extendsjavax.servlet.http.HttpServletRequestWrapper {private HttpSession session;private HttpServletRequest request;private HttpServletResponse response;private String sid &＃61; "";public HttpServletRequestWrapper(HttpServletRequest request) {super(request);}public HttpServletRequestWrapper(String sid, HttpServletRequest request) {super(request);this.sid &＃61; sid;}public HttpServletRequestWrapper(String sid, HttpServletRequest request,HttpServletResponse response) {super(request);this.request &＃61; request;this.response &＃61; response;this.sid &＃61; sid;if (this.session &＃61;&＃61; null) {this.session &＃61; new HttpSessionWrapper(sid, super.getSession(false),request, response);}}&＃64;Overridepublic HttpSession getSession(boolean create) {if (this.session &＃61;&＃61; null) {if (create) {this.session &＃61; new HttpSessionWrapper(this.sid,super.getSession(create), this.request, this.response);return this.session;} else {return null;}}return this.session;}&＃64;Overridepublic HttpSession getSession() {if (this.session &＃61;&＃61; null) {this.session &＃61; new HttpSessionWrapper(this.sid, super.getSession(),this.request, this.response);}return this.session;}}

&＃xff08;3&＃xff09;SessionFilter拦截器的实现


public class SessionFilter extends OncePerRequestFilter implements Filter {private static final Logger LOG &＃61; Logger.getLogger(SessionFilter.class);&＃64;Overrideprotected void doFilterInternal(HttpServletRequest request,HttpServletResponse response, FilterChain filterChain)throws ServletException, IOException {//从COOKIE中获取sessionId&＃xff0c;如果此次请求没有sessionId&＃xff0c;重写为这次请求设置一个sessionIdString sid &＃61; COOKIEUtil.getCOOKIEValue(request, GlobalConstant.JSESSIONID);if(StringUtils.isEmpty(sid) || sid.length() !&＃61; 36){sid &＃61; StringUtil.getUuid();COOKIEUtil.setCOOKIE(request, response, GlobalConstant.JSESSIONID, sid, 60 * 60); }//交给自定义的HttpServletRequestWrapper处理filterChain.doFilter(new HttpServletRequestWrapper(sid, request, response), response);}}

&＃xff08;4&＃xff09;SessionService实现session从redis的读写存储


public class SessionService {private final static Logger LOG &＃61; Logger.getLogger(SessionService.class);private JdkSerializationRedisSerializer jdkSerializer &＃61; new JdkSerializationRedisSerializer();&＃64;Autowiredprivate RedisTemplate redisTemplate;&＃64;SuppressWarnings("unchecked")public Map getSession(String sid) {Map session &＃61; new HashMap();try {Object obj &＃61; redisTemplate.opsForValue().get(RedisKeyUtil.SESSION_DISTRIBUTED_SESSIONID &＃43; sid);if(obj !&＃61; null){obj &＃61; jdkSerializer.deserialize((byte[])obj);session &＃61; (Map) obj;}} catch (Exception e) {LOG.error("Redis获取session异常" &＃43; e.getMessage(), e.getCause());}return session;}public void saveSession(String sid, Map session) {try {redisTemplates.opsForValue().set(RedisKeyUtil.SESSION_DISTRIBUTED_SESSIONID &＃43; sid,jdkSerializer.serialize(session), RedisKeyUtil.SESSION_TIMEOUT,TimeUnit.MINUTES);} catch (Exception e) {LOG.error("Redis保存session异常" &＃43; e.getMessage(), e.getCause());}}public void removeSession(String sid) {try {redisTemplates.delete(RedisKeyUtil.SESSION_DISTRIBUTED_SESSIONID &＃43; sid);} catch (Exception e) {LOG.error("Redis删除session异常" &＃43; e.getMessage(), e.getCause());}}
}

&＃xff08;5&＃xff09;Session的拦截配置&＃xff0c;一般的我们只需要拦截我们定义的拦截请求拦截&＃xff0c;而不需要所有的都需要拦截。在web.xml中配置SessionFilter。


<filter><filter-name>sessionFilterfilter-name><filter-class>org.andy.shop.session.SessionFilterfilter-class>filter><filter-mapping><filter-name>sessionFilterfilter-name>*.dofilter-mapping>

附&＃xff1a;设计到的工具类

1、StringUtil工具类

/*** String工具类* * &＃64;author andy* &＃64;date 2015-5-16 下午4:04:22* */
public class StringUtil {private StringUtil() {super();}/*** 出去null和""* &＃64;param src* &＃64;return*/public static String formatNull(String src) {return (src &＃61;&＃61; null || "null".equals(src)) ? "" : src;}/*** 判断字符串是否为空的正则表达式&＃xff0c;空白字符对应的unicode编码*/private static final String EMPTY_REGEX &＃61; "[\\s\\u00a0\\u2007\\u202f\\u0009-\\u000d\\u001c-\\u001f]&＃43;";/*** 验证字符串是否为空* * &＃64;param input* &＃64;return*/public static boolean isEmpty(String input) {return input &＃61;&＃61; null || input.equals("") || input.matches(EMPTY_REGEX);}public static boolean isNotEmpty(String input){return !isEmpty(input);}public static String getUuid() {return UUID.randomUUID().toString();}
}

2、COOKIE管理COOKIEUtil工具类

/*** 创建时间&＃xff1a;2016年1月22日 下午8:33:56* * &＃64;author andy* &＃64;version 2.2*/public class COOKIEUtil {private static final String KEY &＃61; "jkdflsffff()kldkjapfdY&＃61;::$B&＃43;DUOWAN";private HttpServletRequest request;private HttpServletResponse response;private static String domain &＃61; "andy.com";public COOKIEUtil(HttpServletRequest request, HttpServletResponse response) {this.request &＃61; request;this.response &＃61; response;}/*** 保存COOKIE* &＃64;param request* &＃64;param response* &＃64;param name COOKIE名称* &＃64;param value COOKIE值* &＃64;param seconds 过期时间(单位秒) -1代表关闭浏览器时COOKIE即过期*/public static void setCOOKIE(HttpServletRequest request,HttpServletResponse response, String name, String value, int seconds) {if (StringUtils.isEmpty(name) || StringUtils.isEmpty(value))return;COOKIE COOKIE &＃61; new COOKIE(name, value);//COOKIE.setDomain(domain);COOKIE.setMaxAge(seconds); COOKIE.setPath("/");response.setHeader("P3P","CP&＃61;&＃39;IDC DSP COR ADM DEVi TAIi PSA PSD IVAi IVDi CONi HIS OUR IND CNT&＃39;");response.addCOOKIE(COOKIE);}/*** 过去COOKIE中保存的值* &＃64;param name* &＃64;return* &＃64;throws UnsupportedEncodingException*/public String getCOOKIEValue(String name)throws UnsupportedEncodingException {COOKIE COOKIEs[] &＃61; request.getCOOKIEs();if (COOKIEs !&＃61; null) {for (int i &＃61; 0; i if (name.equalsIgnoreCase(COOKIEs[i].getName())) {return COOKIEs[i].getValue();}}}return "";}/*** 设置加密的COOKIE* &＃64;param name COOKIE名称* &＃64;param value COOKIE值* &＃64;param seconds 过期时间 -1代表关闭浏览器时COOKIE即过期*/public void setCheckCodeCOOKIE(String name, String value, int seconds) {if (StringUtils.isEmpty(name) || StringUtils.isEmpty(value)) {return;}String md5Value &＃61; MD5Utils.getMD5(KEY &＃43; value);COOKIE COOKIE &＃61; new COOKIE(name, md5Value);//COOKIE.setDomain(domain);COOKIE.setMaxAge(seconds);COOKIE.setPath("/");response.addCOOKIE(COOKIE);}/*** 校验加密的COOKIE* &＃64;param name* &＃64;param value* &＃64;return*/public boolean checkCodeCOOKIE(String name, String value) {if (StringUtils.isEmpty(name) || StringUtils.isEmpty(value)) {return false;}boolean result &＃61; false;String COOKIEValue &＃61; getCOOKIEValue(request, name);if (MD5Utils.getMD5(KEY &＃43; value).equalsIgnoreCase(COOKIEValue)) {result &＃61; true;}return result;}/*** 获取COOKIE值* &＃64;param request* &＃64;param name* &＃64;return*/public static String getCOOKIEValue(HttpServletRequest request, String name) {try {COOKIE COOKIEs[] &＃61; request.getCOOKIEs();if (COOKIEs !&＃61; null) {for (int i &＃61; 0; i if (name.equalsIgnoreCase(COOKIEs[i].getName())) {return COOKIEs[i].getValue();}}}} catch (Exception e) {}return "";}/*** 移除客户端的COOKIE* &＃64;param request* &＃64;param response* &＃64;param name*/public static void removeCOOKIEValue(HttpServletRequest request,HttpServletResponse response, String name) {try {COOKIE COOKIEs[] &＃61; request.getCOOKIEs();if (COOKIEs !&＃61; null && COOKIEs.length > 0) {for (COOKIE COOKIE : COOKIEs) {if (name.equalsIgnoreCase(COOKIE.getName())) {COOKIE &＃61; new COOKIE(name, null);COOKIE.setMaxAge(0);COOKIE.setPath("/");//COOKIE.setDomain(domain);response.addCOOKIE(COOKIE);break;}}}} catch (Exception e) {e.printStackTrace();}}
}

3、redis键key设置类RedisKeyUtil

/*** 创建时间&＃xff1a;2015年9月22日 下午4:51:11* * &＃64;author andy* &＃64;version 2.2*/public class RedisKeyUtil {public static final String SESSION_DISTRIBUTED_SESSIONID &＃61; "session:distributed:"; //分布式session sessionid -- sessionvaluepublic static final Integer SESSION_TIMEOUT &＃61; 2; //session 失效时间2小时}

4、分布式session常量设置类GlobalConstant

/*** 创建时间&＃xff1a;2016年1月23日 上午11:16:56* * 分布式session常量* * &＃64;author andy* &＃64;version 2.2*/public class GlobalConstant {public static final String USER_SESSION_KEY &＃61; "user_session_key";//用户session信息public static final String JSESSIONID &＃61; "YHMJSESSIONID"; //jsessionid
}


分布式session在redis执行结果&＃xff1a;