本文實(shí)例講述了Java簡(jiǎn)單實(shí)現(xiàn)session保存到redis的方法。分享給大家供大家參考，具體如下：
在負(fù)載均衡情況下，如果用戶(hù)訪(fǎng)問(wèn)不同的機(jī)器，如果沒(méi)有做session同步，用戶(hù)就會(huì)被提出，這樣用戶(hù)體驗(yàn)非常不好，所以我們很有必要做session同步，把session放到reids緩存服務(wù)器就能很好的解決問(wèn)題。下面是代碼簡(jiǎn)單的實(shí)現(xiàn)。
一、配置web.xml過(guò)濾器：
<filter> <filter-name>sessionFilter</filter-name> <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class></filter><filter-mapping> <filter-name>sessionFilter</filter-name> <url-pattern>/*</url-pattern></filter-mapping>
二、配置對(duì)應(yīng)的過(guò)濾器名字：
<bean id="sessionFilter" class="com.plateno.interceptor.SessionFilter"> <property name="redisTemplate" ref="redisTemplate"/></bean>
三、SessionFilter的實(shí)現(xiàn)：
public class SessionFilter extends GenericFilterBean { private RedisTemplate redisTemplate; @Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { System.out.println("filter"); HttpServletRequest re = (HttpServletRequest)request; HttpServletResponse res = (HttpServletResponse)response; TerryHttpServletRequestWrapper wrapper = new TerryHttpServletRequestWrapper(re,res,redisTemplate); chain.doFilter(wrapper, response); } public RedisTemplate getRedisTemplate() { return redisTemplate; } public void setRedisTemplate(RedisTemplate redisTemplate) { this.redisTemplate = redisTemplate; }}四、TerryHttpServletRequestWrapper的實(shí)現(xiàn)：
public class TerryHttpServletRequestWrapper extends HttpServletRequestWrapper { private CacheHttpSession session; private HttpServletResponse response; private RedisTemplate redisTemplate; public TerryHttpServletRequestWrapper(HttpServletRequest request, HttpServletResponse response,RedisTemplate redisTemplate) { super(request); this.response = response; this.redisTemplate = redisTemplate; } @Override public HttpSession getSession(boolean create) { if(session != null) { return session; } String sid = "terry" + System.currentTimeMillis(); writeSidToCookie(sid); session = new CacheHttpSession(null,sid,redisTemplate); return session; } @Override public HttpSession getSession() { return getSession(false); } protected void writeSidToCookie(String sid) { Cookie mycookies = new Cookie("terry", sid); mycookies.setMaxAge(-1); mycookies.setDomain("locahost"); mycookies.setPath("/"); response.addCookie(mycookies); }}五、CacheHttpSession的實(shí)現(xiàn)：
public class CacheHttpSession extends HttpSessionWrapper { private String sid; private RedisTemplate redisTemplate; private StringRedisSerializer stringSerializer = new StringRedisSerializer(); public CacheHttpSession(HttpSession session,String sid,RedisTemplate redisTemplate) { super(session); this.sid = sid; this.redisTemplate = redisTemplate; } @SuppressWarnings("unchecked") @Override public Enumeration<String> getAttributeNames() { final byte[] key = stringSerializer.serialize(sid); Object result = redisTemplate.execute(new RedisCallback<Object>() { @Override public Object doInRedis(RedisConnection connection) throws DataAccessException { Set<byte[]> set = connection.keys(key); return set; } }); if(result != null) { Set<byte[]> s = (Set<byte[]>)result; Set<String> ss = new HashSet<String>(); for(byte[] b : s) { ss.add(stringSerializer.deserialize(b)); } Enumeration<String> en = new Vector(ss).elements(); return en; } return null; } @SuppressWarnings("unchecked") @Override public void setAttribute(String name, Object value) { final byte[] key = stringSerializer.serialize(name); final byte[] v = stringSerializer.serialize((String)value); redisTemplate.execute(new RedisCallback<Object>() { @Override public Object doInRedis(RedisConnection connection) throws DataAccessException { connection.set(key, v); return null; } }); } @Override public Object getAttribute(String name) { final byte[] key = stringSerializer.serialize(name); @SuppressWarnings("unchecked") Object value = redisTemplate.execute(new RedisCallback<Object>() { @Override public Object doInRedis(RedisConnection connection) throws DataAccessException { return connection.get(key); } }); return value; } @Override public String getId() { return sid; }}六、HttpSessionWrapper的實(shí)現(xiàn)：
public class HttpSessionWrapper implements HttpSession { private HttpSession session; public HttpSessionWrapper(HttpSession session) { this.session = session; } @Override public long getCreationTime() { return this.session.getCreationTime(); } @Override public String getId() { return this.session.getId(); } @Override public long getLastAccessedTime() { return this.session.getLastAccessedTime(); } @Override public ServletContext getServletContext() { return this.session.getServletContext(); } @Override public void setMaxInactiveInterval(int interval) { this.session.setMaxInactiveInterval(interval); } @Override public int getMaxInactiveInterval() { return this.session.getMaxInactiveInterval(); } @Override public HttpSessionContext getSessionContext() { return this.session.getSessionContext(); } @Override public Object getAttribute(String name) { return this.session.getAttribute(name); } @Override public Object getValue(String name) { return this.session.getValue(name); } @Override public Enumeration<String> getAttributeNames() { return this.session.getAttributeNames(); } @Override public String[] getValueNames() { return this.session.getValueNames(); } @Override public void setAttribute(String name, Object value) { this.session.setAttribute(name,value); } @Override public void putValue(String name, Object value) { this.session.putValue(name,value); } @Override public void removeAttribute(String name) { this.session.removeAttribute(name); } @Override public void removeValue(String name) { this.session.removeValue(name); } @Override public void invalidate() { this.session.invalidate(); } @Override public boolean isNew() { return this.session.isNew(); }}以上代碼就能把session保存到redis，當(dāng)然這其中還有很多問(wèn)題，比如sessionId的生成，session過(guò)去，對(duì)象序列化（測(cè)試為了方便統(tǒng)一用了string），等等很多問(wèn)題。以后有時(shí)間再完善。
希望本文所述對(duì)大家java程序設(shè)計(jì)有所幫助。
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