Spring Boot + Redis 初体验
本文测试环境: Spring Boot 2.1.4.RELEASE + Redis 5.0.4 + CentOS 7
让程序先 run 起来
安装及配置 Redis
参考: How To Install and Configure Redis on CentOS 7
新建 Spring Boot 项目并添加依赖
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
添加 Redis 配置
spring:
redis:
host: 192.168.30.101
port: 6379
database: 0
# password: ******
jedis:
pool:
max-active: 10
min-idle: 0
max-idle: 6
max-wait: -1
测试代码
@Component
public class StringRunner implements CommandLineRunner {
@Autowired
private StringRedisTemplate redisTemplate;
// private RedisTemplate<String, String> redisTemplate;
@Override
public void run(String... args) throws Exception {
String key;
// String: 字符串
System.out.println("====== String ======");
key = "string:string";
redisTemplate.opsForValue().set(key, "string.string", 10, TimeUnit.SECONDS);
redisTemplate.opsForValue().append(key, ".append");
System.out.println(redisTemplate.opsForValue().get(key));
key = "string:number";
redisTemplate.delete(key);
redisTemplate.opsForValue().increment(key);
redisTemplate.opsForValue().decrement(key);
System.out.println(redisTemplate.opsForValue().get(key));
// Hash: 哈希
System.out.println("====== Hash ======");
key = "hash:test";
redisTemplate.delete(key);
redisTemplate.opsForHash().put(key, "key1", "value1");
Map<String, String> map = new HashMap<>();
map.put("key2", "value2");
map.put("key3", "1");
redisTemplate.opsForHash().putAll(key, map);
System.out.println(redisTemplate.opsForHash().entries(key));
System.out.println(redisTemplate.opsForHash().keys(key));
System.out.println(redisTemplate.opsForHash().values(key));
System.out.println(redisTemplate.opsForHash().get(key, "key1"));
System.out.println(redisTemplate.opsForHash().increment(key, "key3", 1L));
redisTemplate.opsForHash().delete(key, "key2");
// List: 列表
System.out.println("====== List ======");
key = "list:test";
redisTemplate.delete(key);
redisTemplate.opsForList().rightPush(key, "1");
redisTemplate.opsForList().leftPush(key, "2");
redisTemplate.opsForList().rightPushAll(key, new String[]{"3", "4", "5"});
List<String> list = redisTemplate.opsForList().range(key, 0, -1);
for(String item : list){
System.out.print(item + ", ");
}
System.out.println();
// Set: 集合
System.out.println("====== Set ======");
key = "set:test";
String key1 = "set:test1";
String key2 = "set:test2";
redisTemplate.delete(key1);
redisTemplate.delete(key2);
redisTemplate.opsForSet().add(key1, "value1", "value2", "value1-1", "value1-2");
System.out.println(redisTemplate.opsForSet().members(key1));
redisTemplate.opsForSet().remove(key1, "value1-1");
redisTemplate.opsForSet().move(key1, "value1", key2);
redisTemplate.opsForSet().add(key2, "value2");
System.out.println(redisTemplate.opsForSet().intersect(key1, key2));// 交集
redisTemplate.opsForSet().intersectAndStore(key1, key2, key);// 交集
System.out.println(redisTemplate.opsForSet().members(key));
System.out.println(redisTemplate.opsForSet().union(key1, key2));// 并集
System.out.println(redisTemplate.opsForSet().difference(key1, Arrays.asList(key2)));// 差集
// zset (sorted set): 有序集合
// 与 Set 类似，略
}
}
更进一步
上文中我们与 Redis 交互使用的是 Spring 封装的 StringRedisTemplate, 源码：
public class StringRedisTemplate extends RedisTemplate<String, String> {
public StringRedisTemplate() {
this.setKeySerializer(RedisSerializer.string());
this.setValueSerializer(RedisSerializer.string());
this.setHashKeySerializer(RedisSerializer.string());
this.setHashValueSerializer(RedisSerializer.string());
}
public StringRedisTemplate(RedisConnectionFactory connectionFactory) {
this();
this.setConnectionFactory(connectionFactory);
this.afterPropertiesSet();
}
protected RedisConnection preProcessConnection(RedisConnection connection, boolean existingConnection) {
return new DefaultStringRedisConnection(connection);
}
}
可以看到 StringRedisTemplate 继承自 RedisTemplate 并在构造函数中设置了 key 和 value 的 Serializer (RedisTemplate 默认使用的是 JdkSerializationRedisSerializer, 在 RedisTemplate 源码中可以看到)
RedisSerializer 源码：
public interface RedisSerializer<T> {
@Nullable
byte[] serialize(@Nullable T var1) throws SerializationException;
@Nullable
T deserialize(@Nullable byte[] var1) throws SerializationException;
static RedisSerializer<Object> java() {
return java((ClassLoader)null);
}
static RedisSerializer<Object> java(@Nullable ClassLoader classLoader) {
return new JdkSerializationRedisSerializer(classLoader);
}
static RedisSerializer<Object> json() {
return new GenericJackson2JsonRedisSerializer();
}
static RedisSerializer<String> string() {
return StringRedisSerializer.UTF_8;
}
}
Spring 同时也封装了几种 Serializer, 如 JdkSerializationRedisSerializer, GenericJackson2JsonRedisSerializer, StringRedisSerializer 等，详见下图：
自定义 RedisTemplate
添加依赖
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.9.8</version>
</dependency>
配置 Serializer
下面代码分别使用了 GenericJackson2JsonRedisSerializer 和 Jackson2JsonRedisSerializer
@Configuration
public class RedisConfig {
@Bean
public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory){
RedisTemplate<String, Object> template = new RedisTemplate<>();
template.setConnectionFactory(factory);
template.setKeySerializer(RedisSerializer.string());
template.setHashKeySerializer(RedisSerializer.string());
// 使用 GenericJackson2JsonRedisSerializer
template.setValueSerializer(RedisSerializer.json());
template.setHashValueSerializer(RedisSerializer.json());
// 使用 Jackson2JsonRedisSerializer
// Jackson2JsonRedisSerializer<Object> jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer<>(Object.class);
// ObjectMapper objectMapper = new ObjectMapper();
// objectMapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
// objectMapper.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
// jackson2JsonRedisSerializer.setObjectMapper(objectMapper);
//
// template.setValueSerializer(jackson2JsonRedisSerializer);
// template.setHashValueSerializer(jackson2JsonRedisSerializer);
return template;
}
}
测试
@Component
public class ObjectRunner implements CommandLineRunner {
@Autowired
private RedisTemplate redisTemplate;
@Override
public void run(String... args) throws Exception {
String key;
System.out.println("====== Object ======");
User user = new User();
user.setId(1);
user.setName("admin");
key = "user:id:" + user.getId();
redisTemplate.opsForValue().set(key, user);
user = (User)redisTemplate.opsForValue().get(key);
System.out.println(user.getName());
}
}
P.S. 用冒号作为分割在 Redis 中是设计 key 的一种不成文原则
源码：GitHub
本人 C# 转 Java 的 newbie, 如果错误或不足欢迎指正，谢谢
参考：
