将Redis集成到您的Spring项目中

本文展示了如何通过注释配置将Redis缓存集成到您的spring项目中。

我们将从Gradle配置开始。我们将使用jedis驱动程序。

group 'com.gkatzioura.spring'
version '1.0-SNAPSHOT'apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'idea'
apply plugin: 'spring-boot'buildscript {repositories {mavenCentral()}dependencies {classpath("org.springframework.boot:spring-boot-gradle-plugin:1.2.5.RELEASE")}
}jar {baseName = 'gs-serving-web-content'version =  '0.1.0'
}sourceCompatibility = 1.8repositories {mavenCentral()
}dependencies {compile "org.springframework.boot:spring-boot-starter-thymeleaf"compile 'org.slf4j:slf4j-api:1.6.6'compile 'ch.qos.logback:logback-classic:1.0.13'compile 'redis.clients:jedis:2.7.0'compile 'org.springframework.data:spring-data-redis:1.5.0.RELEASE'testCompile group: 'junit', name: 'junit', version: '4.11'
}task wrapper(type: Wrapper) {gradleVersion = '2.3'
}

将使用spring注释进行Redis配置。

package com.gkatzioura.spring.config;import org.springframework.cache.CacheManager;
import org.springframework.cache.annotation.CachingConfigurerSupport;
import org.springframework.cache.annotation.EnableCaching;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.cache.RedisCacheManager;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.connection.jedis.JedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.RedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;@Configuration
@EnableCaching
public class RedisConfig extends CachingConfigurerSupport {@Beanpublic JedisConnectionFactory redisConnectionFactory() {JedisConnectionFactory jedisConnectionFactory = new JedisConnectionFactory();jedisConnectionFactory.setUsePool(true);return jedisConnectionFactory;}@Beanpublic RedisSerializer redisStringSerializer() {StringRedisSerializer stringRedisSerializer = new StringRedisSerializer();return stringRedisSerializer;}@Bean(name="redisTemplate")public RedisTemplate<String, String> redisTemplate(RedisConnectionFactory cf,RedisSerializer redisSerializer) {RedisTemplate<String, String> redisTemplate = new RedisTemplate<String, String>();redisTemplate.setConnectionFactory(cf);redisTemplate.setDefaultSerializer(redisSerializer);return redisTemplate;}@Beanpublic CacheManager cacheManager() {return new RedisCacheManager(redisTemplate(redisConnectionFactory(),redisStringSerializer()));}}

下一步是创建我们的缓存界面

package com.gkatzioura.spring.cache;import java.util.Date;
import java.util.List;public interface CacheService {public void addMessage(String user,String message);public List<String> listMessages(String user);}

用户将添加消息，他将能够检索它们。但是，在我们的实施中，与用户相关的消息将保留一分钟的时间。

我们使用Redis的CacheService实现如下。

package com.gkatzioura.spring.cache.impl;import com.gkatzioura.spring.cache.CacheService;
import org.springframework.data.redis.core.ListOperations;
import org.springframework.data.redis.core.RedisOperations;
import org.springframework.data.redis.core.SetOperations;
import org.springframework.stereotype.Service;import javax.annotation.Resource;
import java.time.ZonedDateTime;
import java.time.temporal.ChronoUnit;
import java.util.Date;
import java.util.List;@Service("cacheService")
public class RedisService implements CacheService {@Resource(name = "redisTemplate")private ListOperations<String, String> messageList;@Resource(name = "redisTemplate")private RedisOperations<String,String> latestMessageExpiration;@Overridepublic void addMessage(String user,String message) {messageList.leftPush(user,message);ZonedDateTime zonedDateTime = ZonedDateTime.now();Date date = Date.from(zonedDateTime.plus(1, ChronoUnit.MINUTES).toInstant());latestMessageExpiration.expireAt(user,date);}@Overridepublic List<String> listMessages(String user) {return messageList.range(user,0,-1);}}

我们的缓存机制将保留每个用户发送的消息列表。为此，我们将使用用户作为键来设置ListOperations接口。 RedisOperations界面使我们能够指定密钥的生存时间。在我们的情况下，它用作用户密钥。

接下来，我们创建一个注入了缓存服务的控制器。

package com.gkatzioura.spring.controller;import com.gkatzioura.spring.cache.CacheService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;import java.util.List;@RestController
public class MessageController {@Autowiredprivate CacheService cacheService;@RequestMapping(value = "/message",method = RequestMethod.GET)@ResponseBodypublic List<String> greeting(String user) {List<String> messages = cacheService.listMessages(user);return messages;}@RequestMapping(value = "/message",method = RequestMethod.POST)@ResponseBodypublic String saveGreeting(String user,String message) {cacheService.addMessage(user,message);return "OK";}}

最后但并非最不重要的是我们的Application类

package com.gkatzioura.spring;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;@SpringBootApplication
public class Application {public static void main(String[] args) {SpringApplication.run(Application.class, args);}}

为了运行只是问题