第七章【redis】java对redis基本操作

导redis包

在java中配置redis

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p"
xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.0.xsd"> <!-- 连接池配置 -->
<bean id="jedisPoolConfig" class="redis.clients.jedis.JedisPoolConfig">
<!-- 最大连接数 -->
<property name="maxTotal" value="30" />
<!-- 最大空闲连接数 -->
<property name="maxIdle" value="10" />
<!-- 每次释放连接的最大数目 -->
<property name="numTestsPerEvictionRun" value="1024" />
<!-- 释放连接的扫描间隔（毫秒） -->
<property name="timeBetweenEvictionRunsMillis" value="30000" />
<!-- 连接最小空闲时间 -->
<property name="minEvictableIdleTimeMillis" value="1800000" />
<!-- 连接空闲多久后释放, 当空闲时间>该值 且 空闲连接>最大空闲连接数 时直接释放 -->
<property name="softMinEvictableIdleTimeMillis" value="10000" />
<!-- 获取连接时的最大等待毫秒数,小于零:阻塞不确定的时间,默认-1 -->
<property name="maxWaitMillis" value="1500" />
<!-- 在获取连接的时候检查有效性, 默认false -->
<property name="testOnBorrow" value="true" />
<!-- 在空闲时检查有效性, 默认false -->
<property name="testWhileIdle" value="true" />
<!-- 连接耗尽时是否阻塞, false报异常,ture阻塞直到超时, 默认true -->
<property name="blockWhenExhausted" value="false" />
</bean>

<!-- jedis客户端单机版 -->
<bean id="redisClient" class="redis.clients.jedis.JedisPool">
<constructor-arg name="host" value="192.168.21.128"></constructor-arg>
<constructor-arg name="port" value="6379"></constructor-arg>
<constructor-arg name="poolConfig" ref="jedisPoolConfig"></constructor-arg>
</bean>
<bean id="jedisClient" class="com.taotao.rest.dao.impl.JedisClientSingle"></bean>

<!-- jedis集群版配置 -->
<!-- <bean id="redisClient" class="redis.clients.jedis.JedisCluster">
<constructor-arg name="nodes">
<set>
<bean class="redis.clients.jedis.HostAndPort">
<constructor-arg name="host" value="192.168.21.128"></constructor-arg>
<constructor-arg name="port" value="7001"></constructor-arg>
</bean>
<bean class="redis.clients.jedis.HostAndPort">
<constructor-arg name="host" value="192.168.21.128"></constructor-arg>
<constructor-arg name="port" value="7002"></constructor-arg>
</bean>
<bean class="redis.clients.jedis.HostAndPort">
<constructor-arg name="host" value="192.168.21.128"></constructor-arg>
<constructor-arg name="port" value="7003"></constructor-arg>
</bean>
<bean class="redis.clients.jedis.HostAndPort">
<constructor-arg name="host" value="192.168.21.128"></constructor-arg>
<constructor-arg name="port" value="7004"></constructor-arg>
</bean>
<bean class="redis.clients.jedis.HostAndPort">
<constructor-arg name="host" value="192.168.21.128"></constructor-arg>
<constructor-arg name="port" value="7005"></constructor-arg>
</bean>
<bean class="redis.clients.jedis.HostAndPort">
<constructor-arg name="host" value="192.168.21.128"></constructor-arg>
<constructor-arg name="port" value="7006"></constructor-arg>
</bean>
</set>
</constructor-arg>
<constructor-arg name="poolConfig" ref="jedisPoolConfig"></constructor-arg>
</bean>
<bean id="jedisClientCluster" class="com.taotao.rest.dao.impl.JedisClientCluster"></bean> -->

</beans>

public interface JedisClient {

String get(String key);
String set(String key, String value);
Long hset(String hkey, String key, String value );
String hget(String hkey, String key);
long incr(String key);
//设置key的有效期
long expire(String key, int seconds);
long ttl(String key);
long del(String key);
long hdel(String hkey, String key);
}

import org.springframework.beans.factory.annotation.Autowired;

import com.taotao.rest.dao.JedisClient;

import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;

public class JedisClientSingle implements JedisClient {

@Autowired
private JedisPool jedisPool;

@Override
public String get(String key) {
// TODO Auto-generated method stub
Jedis jedis = jedisPool.getResource();
String string = jedis.get(key);
jedis.close();
return string;
}

@Override
public String set(String key, String value) {
// TODO Auto-generated method stub
Jedis jedis = jedisPool.getResource();
String string = jedis.set(key, value);
jedis.close();
return string;
}

@Override
public Long hset(String hkey, String key, String value) {
// TODO Auto-generated method stub
Jedis jedis = jedisPool.getResource();
Long hset = jedis.hset(hkey, key, value);
jedis.close();
return hset;
}

@Override
public String hget(String hkey, String key) {
// TODO Auto-generated method stub
Jedis jedis = jedisPool.getResource();
String string = jedis.hget(hkey, key);
jedis.close();
return string;
}

@Override
public long incr(String key) {
// TODO Auto-generated method stub
Jedis jedis = jedisPool.getResource();
Long incr = jedis.incr(key);
jedis.close();
return incr;
}

@Override
public long expire(String key, int seconds) {
// TODO Auto-generated method stub
Jedis jedis = jedisPool.getResource();
Long expire = jedis.expire(key, seconds);
jedis.close();
return expire;
}

@Override
public long ttl(String key) {
// TODO Auto-generated method stub
Jedis jedis = jedisPool.getResource();
Long ttl = jedis.ttl(key);
jedis.close();
return ttl;
}

@Override
public long del(String key) {
// TODO Auto-generated method stub
Jedis jedis = jedisPool.getResource();
Long del = jedis.del(key);
jedis.close();
return del;
}

@Override
public long hdel(String hkey, String key) {
// TODO Auto-generated method stub
Jedis jedis = jedisPool.getResource();
Long hdel = jedis.hdel(hkey,key);
jedis.close();
return hdel;
}

}

import org.springframework.beans.factory.annotation.Autowired;

import com.taotao.rest.dao.JedisClient;

import redis.clients.jedis.JedisCluster;

public class JedisClientCluster implements JedisClient {

@Autowired
private JedisCluster jedisCluster;

@Override
public String get(String key) {
// TODO Auto-generated method stub
return jedisCluster.get(key);
}

@Override
public String set(String key, String value) {
// TODO Auto-generated method stub
return jedisCluster.set(key, value);
}

@Override
public Long hset(String hkey, String key, String value) {
// TODO Auto-generated method stub
return jedisCluster.hset(hkey, key, value);
}

@Override
public String hget(String hkey, String key) {
// TODO Auto-generated method stub
return jedisCluster.hget(hkey, key);
}

@Override
public long incr(String key) {
// TODO Auto-generated method stub
return jedisCluster.incr(key);
}

@Override
public long expire(String key, int seconds) {
// TODO Auto-generated method stub
return jedisCluster.expire(key, seconds);
}

@Override
public long ttl(String key) {
// TODO Auto-generated method stub
return jedisCluster.ttl(key);
}

@Override
public long del(String key) {
// TODO Auto-generated method stub
return jedisCluster.del(key);
}

@Override
public long hdel(String hkey, String key) {
// TODO Auto-generated method stub
return jedisCluster.hdel(hkey, key);
}

}

使用redis步骤

try {
从缓存中取内容
}
根据id查数据库（正常的查询sql语句）
try {
向缓存中添加内容
}

@Service
public class ContentServiceImpl implements ContentService {

@Autowired
private TbContentMapper TbContentMapper;
@Autowired
private JedisClient jedisClient;
@Value("${INDES_CONTENT_REDIS_KEY}")
private String INDES_CONTENT_REDIS_KEY;

@Override
public List<TbContent> getContentList(long contentCid) {
// TODO Auto-generated method stub

//从缓存中取内容
try {
String hget = jedisClient.hget(INDES_CONTENT_REDIS_KEY, contentCid + "");
if (!StringUtils.isBlank(hget)) {
//把字符串转化成list
List<TbContent> list = JsonUtils.jsonToList(hget, TbContent.class);
return list;
}
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}

//根据内容分类id查询内容列表
TbContentExample example = new TbContentExample();
Criteria criteria = example.createCriteria();
criteria.andCategoryIdEqualTo(contentCid);
//执行查询
List<TbContent> list = TbContentMapper.selectByExample(example);

//向缓存中添加内容
try {
//把list转换成字符串
String cachString = JsonUtils.objectToJson(list);
jedisClient.hset(INDES_CONTENT_REDIS_KEY, contentCid + "", cachString);
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
return list;
}

}