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java端在使用jedispool 连接redis的时候,在高并发的时候经常死锁,或报连接异常,JedisConnectionException,或者getResource 异常等各种问题
在使用jedispool 的时候一定要注意两点
1。 在获取 jedisPool和jedis的时候加上线程同步,保证不要创建过多的jedispool 和 jedis
2。 用完Jedis实例后需要返还给JedisPool
整理了一下redis工具类,通过大量测试和高并发测试的
package com.caspar.util;import java.util.concurrent.locks.ReentrantLock;import org.apache.log4j.Logger;
import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPoolConfig;/*** Redis 工具类* @author caspar**/
public class RedisUtil {protected static ReentrantLock lockPool = new ReentrantLock();protected static ReentrantLock lockJedis = new ReentrantLock();protected static Logger logger = Logger.getLogger(RedisUtil.class);//Redis服务器IPprivate static String ADDR_ARRAY = FileUtil.getPropertyValue("/properties/redis.properties", "server");//Redis的端口号private static int PORT = FileUtil.getPropertyValueInt("/properties/redis.properties", "port");//访问密码
// private static String AUTH = FileUtil.getPropertyValue("/properties/redis.properties", "auth");//可用连接实例的最大数目,默认值为8;//如果赋值为-1,则表示不限制;如果pool已经分配了maxActive个jedis实例,则此时pool的状态为exhausted(耗尽)。private static int MAX_ACTIVE = FileUtil.getPropertyValueInt("/properties/redis.properties", "max_active");;//控制一个pool最多有多少个状态为idle(空闲的)的jedis实例,默认值也是8。private static int MAX_IDLE = FileUtil.getPropertyValueInt("/properties/redis.properties", "max_idle");;//等待可用连接的最大时间,单位毫秒,默认值为-1,表示永不超时。如果超过等待时间,则直接抛出JedisConnectionException;private static int MAX_WAIT = FileUtil.getPropertyValueInt("/properties/redis.properties", "max_wait");;//超时时间private static int TIMEOUT = FileUtil.getPropertyValueInt("/properties/redis.properties", "timeout");;//在borrow一个jedis实例时,是否提前进行validate操作;如果为true,则得到的jedis实例均是可用的;private static boolean TEST_ON_BORROW = FileUtil.getPropertyValueBoolean("/properties/redis.properties", "test_on_borrow");;private static JedisPool jedisPool = null;/*** redis过期时间,以秒为单位*/public final static int EXRP_HOUR = 60*60; //一小时public final static int EXRP_DAY = 60*60*24; //一天public final static int EXRP_MONTH = 60*60*24*30; //一个月/*** 初始化Redis连接池*/private static void initialPool(){try {JedisPoolConfig config = new JedisPoolConfig();config.setMaxTotal(MAX_ACTIVE);config.setMaxIdle(MAX_IDLE);config.setMaxWaitMillis(MAX_WAIT);config.setTestOnBorrow(TEST_ON_BORROW);jedisPool = new JedisPool(config, ADDR_ARRAY.split(",")[0], PORT, TIMEOUT);} catch (Exception e) {logger.error("First create JedisPool error : "+e);try{//如果第一个IP异常,则访问第二个IPJedisPoolConfig config = new JedisPoolConfig();config.setMaxTotal(MAX_ACTIVE);config.setMaxIdle(MAX_IDLE);config.setMaxWaitMillis(MAX_WAIT);config.setTestOnBorrow(TEST_ON_BORROW);jedisPool = new JedisPool(config, ADDR_ARRAY.split(",")[1], PORT, TIMEOUT);}catch(Exception e2){logger.error("Second create JedisPool error : "+e2);}}}/*** 在多线程环境同步初始化*/private static void poolInit() {//断言 ,当前锁是否已经锁住,如果锁住了,就啥也不干,没锁的话就执行下面步骤assert ! lockPool.isHeldByCurrentThread(); lockPool.lock();try { if (jedisPool == null) { initialPool();}}catch(Exception e){e.printStackTrace();} finally { lockPool.unlock();}}public static Jedis getJedis() {//断言 ,当前锁是否已经锁住,如果锁住了,就啥也不干,没锁的话就执行下面步骤assert ! lockJedis.isHeldByCurrentThread(); lockJedis.lock();if (jedisPool == null) { poolInit();}Jedis jedis = null;try { if (jedisPool != null) { jedis = jedisPool.getResource(); }} catch (Exception e) { logger.error("Get jedis error : "+e);}finally{returnResource(jedis);lockJedis.unlock();}return jedis;} /*** 释放jedis资源* @param jedis*/public static void returnResource(final Jedis jedis) {if (jedis != null && jedisPool !=null) {jedisPool.returnResource(jedis);}}/*** 设置 String* @param key* @param value*/public synchronized static void setString(String key ,String value){try {value = StringUtil.isEmpty(value) ? "" : value;getJedis().set(key,value);} catch (Exception e) {logger.error("Set key error : "+e);}}/*** 设置 过期时间* @param key* @param seconds 以秒为单位* @param value*/public synchronized static void setString(String key ,int seconds,String value){try {value = StringUtil.isEmpty(value) ? "" : value;getJedis().setex(key, seconds, value);} catch (Exception e) {logger.error("Set keyex error : "+e);}}/*** 获取String值* @param key* @return value*/public synchronized static String getString(String key){if(getJedis() == null || !getJedis().exists(key)){return null;}return getJedis().get(key);}}
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