Spring Boot集成Spring Cache 和 Redis
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在Spring Boot中添加spring-boot-starter-data-redis依赖：
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-redis</artifactId> </dependency>
在application.properties中指定redis服务器IP、端口和密码、连接数等：
# Redis服务器地址 spring.redis.host=127.0.0.1 # Redis服务器连接端口 使用默认端口6379可以省略配置 #spring.redis.port=6379 # Redis服务器连接密码（默认为空） #spring.redis.password= # 连接池最大连接数（如果配置<=0，则没有限制 ） spring.redis.jedis.pool.max-active=8
使用StringRedisTemplate 和RedisTemplate
StringRedisTemplate是Spring Boot内置的操作Redis的API实现类,另外还有一个API实现类是RedisTemplate。StringRedisTemplate的API假定所有的数据类型化都是字符类型，即key和value都是字符串类型，对于常见额SpringBoot应用系统，使用字符串操作也已经足够了，而且能方便的通过客户端管理工具管理。StringRedisTemplate继承RedisTemplate，与RedisTemplate不同的是重新设置了序列化策略，使用StringRedisSerialier类来序列化key-value，包括List、Hash、Set等数据结构。
1 @RunWith(SpringRunner.class) 2 @SpringBootTest 3 public class SpringbootCacheApplicationTests { 4 5 @Autowired 6 StringRedisTemplate stringRedisTemplate; //操作 k-v 字符串 7 8 @Autowired 9 RedisTemplate redisTemplate; //k- v 都是对象 10 11 /** 12 * redis 常见 13 * String(字符串) List(列表) Set(集合) Hash(散列) ZSet(有序集合) 14 */ 15 16 @Test 17 public void test1() { 18 stringRedisTemplate.opsForValue().append("StringKey", "字符串数值"); 19 String value = stringRedisTemplate.opsForValue().get("StringKey"); 20 System.out.println(value); 21 } 22 @Test 23 public void test2() { 24 25 Product product = productMapper.getProductById(4L); 26 redisTemplate.opsForValue().set("produxtid4",product); 27 28 } 29 }
spring-boot-autoconfigure-2.0.4.RELEASE.jar包中RedisAutoConfiguration.java已经自动声明了两个redis操作bean：
RedisAutoConfiguration.java实现代码：
因此我们只要在使用的地方注入即可：
@Autowired StringRedisTemplate stringRedisTemplate; //操作 k-v 字符串 @Autowired RedisTemplate redisTemplate; //k- v 都是对象
StringRedisTemplate 提供opsForValue用来操作key-value，如上面的示例，另外还提供了一系列opsForHash()、opsForList()、opsForSet()、opsForZSet()等方法用来操作不同结构类型的数据。
运行上面的测试方法，查看redis客户端：
可以发现，出现了一些无法识别的字符，查看RedisTemplate源码可这个是由于默认使用了JDK的序列化机制，而StringRedisTemplate没有出乱码是因为它修改了序列化器
StringRedisTemplate实现：
1 public class StringRedisTemplate extends RedisTemplate<String, String> { 2 3 /** 4 * Constructs a new <code>StringRedisTemplate</code> instance. {@link #setConnectionFactory(RedisConnectionFactory)} 5 * and {@link #afterPropertiesSet()} still need to be called. 6 */ 7 public StringRedisTemplate() { 8 RedisSerializer<String> stringSerializer = new StringRedisSerializer(); 9 setKeySerializer(stringSerializer); 10 setValueSerializer(stringSerializer); 11 setHashKeySerializer(stringSerializer); 12 setHashValueSerializer(stringSerializer); 13 } 14 15 /** 16 * Constructs a new <code>StringRedisTemplate</code> instance ready to be used. 17 * 18 * @param connectionFactory connection factory for creating new connections 19 */ 20 public StringRedisTemplate(RedisConnectionFactory connectionFactory) { 21 this(); 22 setConnectionFactory(connectionFactory); 23 afterPropertiesSet(); 24 } 25 26 protected RedisConnection preProcessConnection(RedisConnection connection, boolean existingConnection) { 27 return new DefaultStringRedisConnection(connection); 28 } 29 }
RedisTemplate实现，截取默认序列化器相关源码：
1 @Override 2 public void afterPropertiesSet() { 3 4 super.afterPropertiesSet(); 5 6 boolean defaultUsed = false; 7 8 if (defaultSerializer == null) { 9 //默认序列化器使用JdkSerializationRedisSerializer 10 defaultSerializer = new JdkSerializationRedisSerializer( 11 classLoader != null ? classLoader : this.getClass().getClassLoader()); 12 } 13 14 if (enableDefaultSerializer) { 15 16 if (keySerializer == null) { 17 keySerializer = defaultSerializer; 18 defaultUsed = true; 19 } 20 if (valueSerializer == null) { 21 valueSerializer = defaultSerializer; 22 defaultUsed = true; 23 } 24 if (hashKeySerializer == null) { 25 hashKeySerializer = defaultSerializer; 26 defaultUsed = true; 27 } 28 if (hashValueSerializer == null) { 29 hashValueSerializer = defaultSerializer; 30 defaultUsed = true; 31 } 32 } 33 34 if (enableDefaultSerializer && defaultUsed) { 35 Assert.notNull(defaultSerializer, "default serializer null and not all serializers initialized"); 36 } 37 38 if (scriptExecutor == null) { 39 this.scriptExecutor = new DefaultScriptExecutor<>(this); 40 } 41 42 initialized = true; 43 }
既然RedisTemplate的默认序列化器不是很方便在redis管理工具中查看，我们可以自己定义一个RedisTemplate实例，修改默认的序列化器。
实现方式如下，定义一个配置类，重新注入一个RedisTemplate操作bean:
1 @Configuration 2 public class MyRedisConfig { 3 4 @Bean(name = "redisTemplate") 5 public RedisTemplate<String,Object> redisTemplate(RedisConnectionFactory redisConnectionFactory){ 6 7 RedisTemplate<String,Object> redisTemplate = new RedisTemplate<>(); 8 //参照StringRedisTemplate内部实现指定序列化器 9 redisTemplate.setConnectionFactory(redisConnectionFactory); 10 redisTemplate.setKeySerializer(keySerializer()); 11 redisTemplate.setHashKeySerializer(keySerializer()); 12 redisTemplate.setValueSerializer(valueSerializer()); 13 redisTemplate.setHashValueSerializer(valueSerializer()); 14 16 return redisTemplate; 17 } 18 19 private RedisSerializer<String> keySerializer() { 20 return new StringRedisSerializer(); 21 } 22 //使用Jackson序列化器 23 private RedisSerializer<Object> valueSerializer() { 24 return new GenericJackson2JsonRedisSerializer(); 25 } 26 }
重新运行上面的测试代码，可以发现redis客户端中已经可以正常的显示json格式数据了。
SpringBoot集成redis + spring cache
Spring Cache集成redis的运行原理：
Spring缓存抽象模块通过CacheManager来创建、管理实际缓存组件，当SpringBoot应用程序引入spring-boot-starter-data-redi依赖后吗，容器中将注册的是CacheManager实例RedisCacheManager对象，RedisCacheManager来负责创建RedisCache作为缓存管理组件，由RedisCache操作redis服务器实现缓存数据操作。实际测试发现默认注入的RedisCacheManager操作缓存用的是RedisTemplate<Object, Object>，因此我们需要自定义cacheManager，替换掉默认的序列化器。
实现代码：
添加mybatis和redis依赖：
<dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>1.3.2</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-redis</artifactId> </dependency>
添加mapper映射：
1 @Mapper 2 public interface ProductMapper { 3 @Select("select * from tb_product where product_id=#{id}") 4 Product getProductById(Long id); 5 6 @Update("update tb_product set product_name=#{productName},product_desc=#{productDesc} WHERE product_id=#{productId}") 7 int updateProduct(Product product); 8 9 @Delete("delete from tb_product where product_id=#{id}") 10 void deleteProductById(Long id); 11 12 @Select("select * from tb_product where product_name=#{productName}") 13 Product getProductByName(String productName); 14 }
Service:
1 package com.sl.cache.service; 2 import com.sl.cache.entity.Product; 3 import com.sl.cache.mapper.ProductMapper; 4 import org.springframework.beans.factory.annotation.Autowired; 5 import org.springframework.cache.annotation.CacheConfig; 6 import org.springframework.cache.annotation.CacheEvict; 7 import org.springframework.cache.annotation.CachePut; 8 import org.springframework.cache.annotation.Cacheable; 9 import org.springframework.cache.annotation.Caching; 10 import org.springframework.stereotype.Service; 11 12 @Service 13 @CacheConfig(cacheNames = "product") 14 public class ProductService { 15 @Autowired 16 private ProductMapper productMapper; 17 18 @Cacheable(cacheNames = "product1",key = "#root.methodName+\'[\'+#id+\']\'") 19 //@Cacheable(cacheNames = {"product1","product2"})// 默认key为参数，多个参数SimpleKey [arg1,arg2] 20 //@Cacheable(cacheNames = "product",key = "#root.methodName+\'[\'+#id+\']\'") 21 //@Cacheable(cacheNames = "product",keyGenerator = "myKeyGenerator") 22 //@Cacheable(cacheNames = "product",key = "#root.methodName+\'[\'+#id+\']\'",condition="#a0>10",unless = "#a0==11") //或者condition="#id>10") 23 public Product getProductById(Long id){ 24 Product product =productMapper.getProductById(id); 25 System.out.println(product); 26 return product; 27 } 28 29 @CachePut(value="product",key = "#result.productId",condition = "#result!=null") 30 public Product updateProduct(Product product){ 31 int count = productMapper.updateProduct(product); 32 System.out.println("影响行数："+count); 33 if(count>0){ 34 return product; 35 }else{ 36 return null; 37 } 38 } 39 40 //@CacheEvict(value="product",key="#id") 41 //@CacheEvict(value="product",allEntries = true) //清楚所有缓存 42 @CacheEvict(value="product",allEntries = true,beforeInvocation = true) //清楚所有缓存 43 public boolean deleteProductById(Long id) { 44 productMapper.deleteProductById(id); 45 return true; 46 } 47 48 //含有CachePut注解，所以执行这个方法时一定会查询数据库，及时有cacheable注解 49 @Caching( 50 cacheable = {@Cacheable(value="product",key="#productName")}, 51 put = { 52 @CachePut(value="product",key="#result.productId"), 53 @CachePut(value="product",key="#result.productName") 54 } 55 ) 56 public Product getProductByName(String productName){ 57 58 Product product =productMapper.getProductByName(productName); 59 60 return product; 61 } 62 }
Controller:
package com.sl.cache.controller; import com.sl.cache.entity.Product; import com.sl.cache.service.ProductService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.stereotype.Service; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.RestController; @RestController public class ProductController { @Autowired private ProductService productService; @GetMapping("/product/{id}") public Product getProduct(@PathVariable("id") Long id) { Product product = productService.getProductById(id); return product; } //prooduct?productid=1&productName= & @GetMapping("/product") public Product updateProduct(Product product) { productService.updateProduct(product); return product; } @GetMapping("/delproduct") public String delProduct(@RequestParam(value="id") Long id) { productService.deleteProductById(id); return "ok"; } @GetMapping("/product/name/{productName}") public Product getEmpByLastName(@PathVariable("productName") String productName){ return productService.getProductByName(productName); } }
自定义cacheManager实现：
1 package com.sl.cache.config; 2 import com.sl.cache.entity.Product; 3 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean; 4 import org.springframework.cache.CacheManager; 5 import org.springframework.cache.config.CacheManagementConfigUtils; 6 import org.springframework.context.annotation.Bean; 7 import org.springframework.context.annotation.Configuration; 8 import org.springframework.context.annotation.Primary; 9 import org.springframework.data.redis.cache.RedisCacheConfiguration; 10 import org.springframework.data.redis.cache.RedisCacheManager; 11 import org.springframework.data.redis.cache.RedisCacheWriter; 12 import org.springframework.data.redis.connection.RedisConnectionFactory; 13 import org.springframework.data.redis.core.RedisTemplate; 14 import org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer; 15 import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer; 16 import org.springframework.data.redis.serializer.RedisSerializationContext; 17 import org.springframework.data.redis.serializer.RedisSerializer; 18 import org.springframework.data.redis.serializer.StringRedisSerializer; 19 20 import java.net.UnknownHostException; 21 import java.time.Duration; 22 23 @Configuration 24 public class MyRedisConfig { 25 26 @Bean(name = "redisTemplate") 27 public RedisTemplate<String,Object> redisTemplate(RedisConnectionFactory redisConnectionFactory){ 28 29 RedisTemplate<String,Object> redisTemplate = new RedisTemplate<>(); 30 31 redisTemplate.setConnectionFactory(redisConnectionFactory); 32 redisTemplate.setKeySerializer(keySerializer()); 33 redisTemplate.setHashKeySerializer(keySerializer()); 34 redisTemplate.setValueSerializer(valueSerializer()); 35 redisTemplate.setHashValueSerializer(valueSerializer()); 36 return redisTemplate; 37 } 38 39 @Primary 40 @Bean 41 public CacheManager cacheManager(RedisConnectionFactory redisConnectionFactory){ 42 //缓存配置对象 43 RedisCacheConfiguration redisCacheConfiguration = RedisCacheConfiguration.defaultCacheConfig(); 44 45 redisCacheConfiguration = redisCacheConfiguration.entryTtl(Duration.ofMinutes(30L)) //设置缓存的默认超时时间：30分钟 46 .disableCachingNullValues() //如果是空值，不缓存 47 .serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(keySerializer())) //设置key序列化器 48 .serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer((valueSerializer()))); //设置value序列化器 49 50 return RedisCacheManager 51 .builder(RedisCacheWriter.nonLockingRedisCacheWriter(redisConnectionFactory)) 52 .cacheDefaults(redisCacheConfiguration).build(); 53 } 54 private RedisSerializer<String> keySerializer() { 55 return new StringRedisSerializer(); 56 } 57 58 private RedisSerializer<Object> valueSerializer() { 59 return new GenericJackson2JsonRedisSerializer(); 60 } 61 }
启用缓存，添加mybatis Mapper映射扫描：
1 @MapperScan("com.sl.cache.mapper") 2 @SpringBootApplication 3 @EnableCaching 4 public class SpringbootCacheApplication { 5 6 public static void main(String[] args) { 7 SpringApplication.run(SpringbootCacheApplication.class, args); 8 9 } 10 }
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