本篇文章主要介绍了spring整合redis缓存并以注解(@Cacheable、@CachePut、@CacheEvict)形式使用,具有一定的参考价值,有兴趣的可以了解一下。
maven项目中在pom.xml中依赖2个jar包,其他的spring的jar包省略:
<dependency> <groupId>redis.clients</groupId> <artifactId>jedis</artifactId> <version>2.8.1</version> </dependency> <dependency> <groupId>org.springframework.data</groupId> <artifactId>spring-data-redis</artifactId> <version>1.7.2.RELEASE</version> </dependency>
spring-Redis.xml中的内容:
<?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" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:cache="http://www.springframework.org/schema/cache" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.2.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.2.xsd http://www.springframework.org/schema/cache http://www.springframework.org/schema/cache/spring-cache-4.2.xsd"> <context:property-placeholder location="classpath:redis-config.properties" /> <!-- 启用缓存注解功能,这个是必须的,否则注解不会生效,另外,该注解一定要声明在spring主配置文件中才会生效 --> <cache:annotation-driven cache-manager="cacheManager" /> <!-- 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> <!-- spring自己的缓存管理器,这里定义了缓存位置名称 ,即注解中的value --> <bean id="cacheManager" class="org.springframework.cache.support.SimpleCacheManager"> <property name="caches"> <set> <!-- 这里可以配置多个redis --> <!-- <bean class="com.cn.util.RedisCache"> <property name="redisTemplate" ref="redisTemplate" /> <property name="name" value="default"/> </bean> --> <bean class="com.cn.util.RedisCache"> <property name="redisTemplate" ref="redisTemplate" /> <property name="name" value="common"/> <!-- common名称要在类或方法的注解中使用 --> </bean> </set> </property> </bean> </beans>
redis-config.properties中的内容:
# 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
com.cn.util.RedisCache类中的内容:
package com.cn.util; 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; 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; } }
到了这一步,大部分人会想在web.xml的启动配置文件地方(context-param)加入了spring-redis.xml,让项目启动时加载这个配置文件吧,但是这样启动后注解不生效。
正确的做法是:web.xml中配置了servlet控制器:
<servlet> <servlet-name>SpringMVC</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>/WEB-INF/spring-mvc.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> <async-supported>true</async-supported> </servlet>
在DispatcherServlet的初始化过程中,框架会在web应用的 WEB-INF文件夹下寻找名为spring-mvc.xml的配置文件,如果不指定的话,默认是applicationContext.xml
只需要在spring-mvc.xml文件中引入spring-redis配置文件即可,正如spring-redis.xml中的启用注解说的:f57e5a6503de65c9ad8bae730b9f0dc9注解一定要声明在spring主配置文件中才会生效。
spring-mvc.xml内容,省略了spring与spring MVC整合的那部分:
<?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" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.2.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.2.xsd"> <!-- 自动扫描该包,使SpringMVC认为包下用了@controller注解的类是控制器 --> <context:component-scan base-package="com.cn" /> <!-- 引入同文件夹下的redis属性配置文件 --> <import resource="spring-redis.xml"/> </beans>
在service的实现类中:
@Service public class UserServiceImpl implements UserService{ @Autowired private UserBo userBo; @Cacheable(value="common",key="'id_'+#id") public User selectByPrimaryKey(Integer id) { return userBo.selectByPrimaryKey(id); } @CachePut(value="common",key="#user.getUserName()") public void insertSelective(User user) { userBo.insertSelective(user); } @CacheEvict(value="common",key="'id_'+#id") public void deleteByPrimaryKey(Integer id) { userBo.deleteByPrimaryKey(id); } }
以上是spring整合redis缓存并以注解形式使用的实例详解的详细内容。更多信息请关注PHP中文网其他相关文章!