Dogpile effect of java-no.06 read-write lock control cache failure illumination

package cn.guagua.mobile.common;import java.util.concurrent.locks.lock;import  Java.util.concurrent.locks.readwritelock;import java.util.concurrent.locks.reentrantreadwritelock;import  org.apache.log4j.Logger;import cn.guagua.mobile.cache.redis.Redis;/** *  read/write lock control forced read cache synchronization  *  @author  shma *  @date  2014-10-11 15:04:28 */public class  synchcachelock<t> {private static final logger logger =  Logger.getlogger (synchcachelock.class);p rivate static redis.redisclient redis1 = new  redis.redisclient ("1");p rivate readwritelock lock = null;private lock  readlock = null; //  Read Lock     private lock writelock =  null; //  write lock Public synchcachelock ()  {lock = new reentrantreadwritelock (); Readlock = lock.readlock (); writelock = lock.writelock (); System.out.println (Thread.CurrentThread (). GetName ()  +  ">>> cache lock init ...");} Public t getcache (String key, runnable task)  {T obj = null; Readlock.lock ();try {obj =  (T)  redis1.getobject (key); if (obj == null)  { System.out.println (Thread.CurrentThread (). GetName ()  +   read request   +  key +  " is null, wait query ..."); Readlock.unlock (); Writelock.lock (); try { obj =  (T)  redis1.getobject (key); if (obj == null)  {task.run ();// Enforce write Cache task System.out.println (Thread.CurrentThread (). GetName ()  +  " read request "  + key +  " end ...");obj =  (T)  redis1.getobject (key);}  catch (throwable e)  {system.out.println ("Readlock error ..."); E.printstacktrace ();}  finally {readlock.lock ();  &Nbsp;          writelock.unlock ();}} System.out.println (Thread.CurrentThread (). GetName ()  +   read request   +  key +  " data ...");  catch (throwable e)  {system.out.println ("Lock error ..."); E.printstacktrace ();}  finally {readlock.unlock ();} Return obj;}}

Dogpile effect of java-no.06 read-write lock control cache failure illumination