03.redis+ssm整合（mybatis二级缓存）

SSM+redis整合

ssm框架之前已经搭建过了，这里不再做代码复制工作。

这里主要是利用redis去做mybatis的二级缓存，mybaits映射文件中所有的select都会刷新已有缓存，如果不存在就会新建缓存，所有的insert，update操作都会更新缓存。

redis的好处也显而易见，可以使系统的数据访问性能更高。本节只是展示了整合方法和效果，后面会补齐redis集群、负载均衡和session共享的文章。

下面就开始整合工作：

后台首先启动redis-server（后台启动与远程连接linux服务的方法都需要改redis.conf文件），启动命令“./src/redis-server ./redis.conf”

我这里是windows系统下开发的，推荐一个可视化工具“Redis Desktop manager”,需要远程连接linux下的redis，需要linux下开启端口对外开放（具体方法是修改/etc/sysconfig/iptables文件，增加对外端口开发命令）。

以上操作都完成后，即可远程连接成功了，如图：

现在还没有缓存记录，下面进入代码阶段，首先在pom.xml中增加需要的redis jar包

 1  2             redis.clients 3             jedis 4             2.9.0 5          6          7          8             org.springframework.data 9             spring-data-redis10             1.6.2.RELEASE11         12         13         14             org.mybatis15             mybatis-ehcache16             1.0.017         18           19         20             com.alibaba21             druid22             1.0.2423         

pom.xml写好后，还需要新增两个配置文件：redis.properties

redis.host=192.168.0.109
redis.port=6379
redis.pass=123456
redis.maxIdle=200
redis.maxActive=1024
redis.maxWait=10000
redis.testOnBorrow=true

其中字段也都很好理解，再加入配置文件：spring-redis.xml

 1 19       20       21     22      23      24     25         26         27         28     29     30     31     32         33         34         35          36     37     38     39     52     53         54     55 

配置文件写好后，就开始java代码的编写：

JedisClusterFactory.java

  1 package com.cjl.util;  2   3 import java.util.HashSet;  4 import java.util.Properties;  5 import java.util.Set;  6 import java.util.regex.Pattern;  7   8 import org.apache.commons.pool2.impl.GenericObjectPoolConfig;  9 import org.springframework.beans.factory.FactoryBean; 10 import org.springframework.beans.factory.InitializingBean; 11 import org.springframework.core.io.Resource; 12  13 import redis.clients.jedis.HostAndPort; 14 import redis.clients.jedis.JedisCluster; 15  16 public class JedisClusterFactory implements FactoryBean, InitializingBean { 17  18     private Resource addressConfig; 19     private String addressKeyPrefix; 20  21     private JedisCluster jedisCluster; 22     private Integer timeout; 23     private Integer maxRedirections; 24     private GenericObjectPoolConfig genericObjectPoolConfig; 25  26     private Pattern p = Pattern.compile("^.+[:]\\d{1,5}\\s*$"); 27  28     public JedisCluster getObject() throws Exception { 29         return jedisCluster; 30     } 31  32     public Class getObjectType() { 33         return (this.jedisCluster != null ? this.jedisCluster.getClass() : JedisCluster.class); 34     } 35  36     public boolean isSingleton() { 37         return true; 38     } 39  40     private Set parseHostAndPort() throws Exception { 41         try { 42             Properties prop = new Properties(); 43             prop.load(this.addressConfig.getInputStream()); 44  45             Set haps = new HashSet(); 46             for (Object key : prop.keySet()) { 47  48                 if (!((String) key).startsWith(addressKeyPrefix)) { 49                     continue; 50                 } 51  52                 String val = (String) prop.get(key); 53  54                 boolean isIpPort = p.matcher(val).matches(); 55  56                 if (!isIpPort) { 57                     throw new IllegalArgumentException("ip 或 port 不合法"); 58                 } 59                 String[] ipAndPort = val.split(":"); 60  61                 HostAndPort hap = new HostAndPort(ipAndPort[0], Integer.parseInt(ipAndPort[1])); 62                 haps.add(hap); 63             } 64  65             return haps; 66         } catch (IllegalArgumentException ex) { 67             throw ex; 68         } catch (Exception ex) { 69             throw new Exception("解析 jedis 配置文件失败", ex); 70         } 71     } 72  73     public void afterPropertiesSet() throws Exception { 74         Set haps = this.parseHostAndPort(); 75  76         jedisCluster = new JedisCluster(haps, timeout, maxRedirections, genericObjectPoolConfig); 77  78     } 79  80     public void setAddressConfig(Resource addressConfig) { 81         this.addressConfig = addressConfig; 82     } 83  84     public void setTimeout(int timeout) { 85         this.timeout = timeout; 86     } 87  88     public void setMaxRedirections(int maxRedirections) { 89         this.maxRedirections = maxRedirections; 90     } 91  92     public void setAddressKeyPrefix(String addressKeyPrefix) { 93         this.addressKeyPrefix = addressKeyPrefix; 94     } 95  96     public void setGenericObjectPoolConfig(GenericObjectPoolConfig genericObjectPoolConfig) { 97         this.genericObjectPoolConfig = genericObjectPoolConfig; 98     } 99 100 }

RedisCache.java

  1 package com.cjl.util;  2   3 import java.util.concurrent.locks.ReadWriteLock;  4 import java.util.concurrent.locks.ReentrantReadWriteLock;  5   6 import org.apache.ibatis.cache.Cache;  7 import org.slf4j.Logger;  8 import org.slf4j.LoggerFactory;  9 import org.springframework.data.redis.connection.jedis.JedisConnection; 10 import org.springframework.data.redis.connection.jedis.JedisConnectionFactory; 11 import org.springframework.data.redis.serializer.JdkSerializationRedisSerializer; 12 import org.springframework.data.redis.serializer.RedisSerializer; 13  14 import redis.clients.jedis.exceptions.JedisConnectionException; 15  16 public class RedisCache implements Cache { 17     private static final Logger logger = LoggerFactory.getLogger(RedisCache.class); 18  19     private static JedisConnectionFactory jedisConnectionFactory; 20  21     private final String id; 22  23     private final ReadWriteLock rwl = new ReentrantReadWriteLock(); 24      25  26     public RedisCache(final String id) { 27         if (id == null) { 28             throw new IllegalArgumentException("Cache instances require an ID"); 29         } 30         logger.debug("MybatisRedisCache:id=" + id); 31         this.id = id; 32     } 33  34     /** 35      * 清空所有缓存 36      */ 37     public void clear() { 38         rwl.readLock().lock(); 39         JedisConnection connection = null; 40         try { 41             connection = jedisConnectionFactory.getConnection(); 42             connection.flushDb(); 43             connection.flushAll(); 44         } catch (JedisConnectionException e) { 45             e.printStackTrace(); 46         } finally { 47             if (connection != null) { 48                 connection.close(); 49             } 50             rwl.readLock().unlock(); 51         } 52     } 53  54     public String getId() { 55         return this.id; 56     } 57  58     /** 59      * 获取缓存总数量 60      */ 61     public int getSize() { 62         int result = 0; 63         JedisConnection connection = null; 64         try { 65             connection = jedisConnectionFactory.getConnection(); 66             result = Integer.valueOf(connection.dbSize().toString()); 67             logger.info("添加mybaits二级缓存数量：" + result); 68         } catch (JedisConnectionException e) { 69             e.printStackTrace(); 70         } finally { 71             if (connection != null) { 72                 connection.close(); 73             } 74         } 75         return result; 76     } 77  78     public void putObject(Object key, Object value) { 79         rwl.writeLock().lock(); 80  81         JedisConnection connection = null; 82         try { 83             connection = jedisConnectionFactory.getConnection(); 84             RedisSerializer