SpringDataRedis简介

1项目常见问题思考

当每天大量流量访问系统的时候会对系统早上大量的压力 解决方式之一就是缓存,另一种是网页静态化。今天我先贴出第一种方法的配置第二种方法日后再发布。

2 Redis官网介绍

redis是一款开源的Key-Value数据库,运行在内存中,由ANSI C编写。企业开发通常采用Redis来实现缓存。同类的产品还有memcache 、memcached 、MongoDB等。
本人的网络官网访问不了 先看中文的吧

3 Jedis

Jedis是Redis官方推出的一款面向Java的客户端,提供了很多接口供Java语言调用。可以在Redis官网下载,当然还有一些开源爱好者提供的客户端,如Jredis、SRP等等,推荐使用Jedis。

4 Spring Data Redis

Spring-data-redis是spring大家族的一部分,提供了在srping应用中通过简单的配置访问redis服务,对reids底层开发包(Jedis,  JRedis, and RJC)进行了高度封装,RedisTemplate提供了redis各种操作、异常处理及序列化,支持发布订阅,并对spring 3.1 cache进行了实现。

spring-data-redis针对jedis提供了如下功能:
  1. 连接池自动管理,提供了一个高度封装的“RedisTemplate”类
  2. 针对jedis客户端中大量api进行了归类封装,将同一类型操作封装为operation接口

    • ValueOperations:简单K-V操作
    • SetOperations:set类型数据操作
    • ZSetOperations:zset类型数据操作
    • HashOperations:针对map类型的数据操作
    • ListOperations:针对list类型的数据操作

5 准备工作

(1)构建Maven工程 spring_data_redis_demo

(2)引入Spring相关依赖、引入JUnit依赖 (内容参考资料中配置文件)

(3)引入Jedis和SpringDataRedis依赖

  • pom.xml
  • <!-- 缓存 -->
           <dependency>
               <groupId>redis.clients</groupId>
               <artifactId>jedis</artifactId>
           </dependency>
           <dependency>
               <groupId>org.springframework.data</groupId>
               <artifactId>spring-data-redis</artifactId>
           </dependency>
           <dependency>
               <groupId>org.springframework.data</groupId>
               <artifactId>spring-data-commons</artifactId>
               <version>1.8.4.RELEASE</version>
           </dependency>
           <dependency>
               <groupId>org.apache.commons</groupId>
               <artifactId>commons-pool2</artifactId>
           </dependency>
  • spring/applicationContext-redis.xml
  • <?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
           xmlns:context="http://www.springframework.org/schema/context"
           xsi:schemaLocation="http://www.springframework.org/schema/beans
                http://www.springframework.org/schema/beans/spring-beans.xsd   
                http://www.springframework.org/schema/context   
                http://www.springframework.org/schema/context/spring-context.xsd   ">
    
        <context:property-placeholder location="classpath*:properties/*.properties"/>
    
        <!-- redis 相关配置 -->
        <bean id="poolConfig" class="redis.clients.jedis.JedisPoolConfig">
            <property name="maxIdle" value="${redis.maxIdle}"/>
            <property name="maxWaitMillis" value="${redis.maxWait}"/>
            <property name="testOnBorrow" value="${redis.testOnBorrow}"/>
        </bean>
    
        <bean id="JedisConnectionFactory" class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory"
              p:host-name="${redis.host}" p:port="${redis.port}" p:password="${redis.pass}" p:pool-config-ref="poolConfig"/>
    
        <bean id="redisTemplate" class="org.springframework.data.redis.core.RedisTemplate">
            <property name="connectionFactory" ref="JedisConnectionFactory"/>
        </bean>
    
    </beans>  
    • maxIdle :最大空闲数
    • maxWaitMillis:连接时的最大等待毫秒数
    • testOnBorrow:在提取一个jedis实例时,是否提前进行验证操作;如果为true,则得到的jedis实例均是可用的;
  • properties/redis-config.properties 工具类
  • # Redis settings 
    # server IP 
    redis.host=127.0.0.1
    # server port 
    redis.port=6379
    # server pass 
    redis.pass=
    # use dbIndex 
    redis.database=0
    # 控制一个pool最多有多少个状态为idle(空闲的)的jedis实例
    redis.maxIdle=300
    #表示当borrow(引入)一个jedis实例时,最大的等待时间,如果超过等待时间(毫秒),则直接抛出JedisConnectionException;
    redis.maxWait=3000
    # 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  
    redis.testOnBorrow=true
  • utils.RedisCache
  • package utils;
    import java.io.ByteArrayInputStream; 
    import java.io.ByteArrayOutputStream; 
    import java.io.IOException; 
    import java.io.ObjectInputStream; 
    import java.io.ObjectOutputStream; 
      
    import org.springframework.cache.Cache; 
    import org.springframework.cache.support.SimpleValueWrapper; 
    import org.springframework.dao.DataAccessException; 
    import org.springframework.data.redis.connection.RedisConnection; 
    import org.springframework.data.redis.core.RedisCallback; 
    import org.springframework.data.redis.core.RedisTemplate;
    //    Redis缓存管理类
    // @author Administrator
    public class RedisCache implements Cache{
    
          private RedisTemplate<String, Object> redisTemplate;  
          private String name;  
          public RedisTemplate<String, Object> getRedisTemplate() { 
            return redisTemplate;  
          } 
             
          public void setRedisTemplate(RedisTemplate<String, Object> redisTemplate) { 
            this.redisTemplate = redisTemplate;  
          } 
             
          public void setName(String name) { 
            this.name = name;  
          } 
             
          @Override 
          public String getName() { 
            // TODO Auto-generated method stub  
            return this.name;  
          } 
          
          @Override 
          public Object getNativeCache() { 
           // TODO Auto-generated method stub  
            return this.redisTemplate;  
          } 
           
          @Override 
          public ValueWrapper get(Object key) { 
           // TODO Auto-generated method stub 
           System.out.println("get key"); 
           final String keyf = key.toString(); 
           Object object = null; 
           
           
           object = redisTemplate.execute(new RedisCallback<Object>() { 
           public Object doInRedis(RedisConnection connection)  
                 throws DataAccessException { 
             byte[] key = keyf.getBytes(); 
             byte[] value = connection.get(key); 
             if (value == null) { 
               return null; 
              } 
             return toObject(value); 
             } 
            }); 
            return (object != null ? new SimpleValueWrapper(object) : null); 
           } 
           
           @Override 
           public void put(Object key, Object value) { 
            // TODO Auto-generated method stub 
            System.out.println("put key"); 
            final String keyf = key.toString();  
            final Object valuef = value;  
            final long liveTime = 86400;  
            redisTemplate.execute(new RedisCallback<Long>() {  
              public Long doInRedis(RedisConnection connection)  
                  throws DataAccessException {  
                byte[] keyb = keyf.getBytes();  
                byte[] valueb = toByteArray(valuef);  
                connection.set(keyb, valueb);  
                if (liveTime > 0) {  
                  connection.expire(keyb, liveTime);  
                 }  
                return 1L;  
               }  
             });  
           } 
          
           private byte[] toByteArray(Object obj) {  
             byte[] bytes = null;  
             ByteArrayOutputStream bos = new ByteArrayOutputStream();  
             try {  
              ObjectOutputStream oos = new ObjectOutputStream(bos);  
              oos.writeObject(obj);  
              oos.flush();  
              bytes = bos.toByteArray();  
              oos.close();  
              bos.close();  
             }catch (IOException ex) {  
                ex.printStackTrace();  
             }  
             return bytes;  
            }  
          
            private Object toObject(byte[] bytes) { 
             Object obj = null;  
              try { 
                ByteArrayInputStream bis = new ByteArrayInputStream(bytes);  
                ObjectInputStream ois = new ObjectInputStream(bis);  
                obj = ois.readObject();  
                ois.close();  
                bis.close();  
              } catch (IOException ex) {  
                ex.printStackTrace();  
              } catch (ClassNotFoundException ex) {  
                ex.printStackTrace();  
              }  
              return obj;  
            } 
           
            @Override 
            public void evict(Object key) {  
             // TODO Auto-generated method stub  
             System.out.println("del key"); 
             final String keyf = key.toString();  
             redisTemplate.execute(new RedisCallback<Long>() {  
             public Long doInRedis(RedisConnection connection)  
                  throws DataAccessException {  
               return connection.del(keyf.getBytes());  
              }  
             });  
            } 
           
            @Override 
            public void clear() {  
              // TODO Auto-generated method stub  
              System.out.println("clear key"); 
              redisTemplate.execute(new RedisCallback<String>() {  
                public String doInRedis(RedisConnection connection)  
                    throws DataAccessException {  
                 connection.flushDb();  
                  return "ok";  
                }  
              });  
            } 
          
            @Override
            public <T> T get(Object key, Class<T> type) { 
              // TODO Auto-generated method stub 
              return null; 
            } 
            
            @Override
            public ValueWrapper putIfAbsent(Object key, Object value) { 
              // TODO Auto-generated method stub 
              return null; 
            } 
    }
    

source
24 声望2 粉丝

目标:用半年的时间记录之前两三年中遇到的java问题