Spring Boot教程（三十四）使用Redis数据库

Posted 2020-10-26 allalongx

除了String类型，实战中我们还经常会在Redis中存储对象，这时候我们就会想是否可以使用类似RedisTemplate<String, User>来初始化并进行操作。但是Spring Boot并不支持直接使用，需要我们自己实现RedisSerializer<T>接口来对传入对象进行序列化和反序列化，下面我们通过一个实例来完成对象的读写操作。

• 创建要存储的对象：User

  public class User implements Serializable {
  
      private static final long serialVersionUID = -1L;
  
      private String username;
      private Integer age;
  
      public User(String username, Integer age) {
          this.username = username;
          this.age = age;
      }
  
      // 省略getter和setter
  
  }
  

  　　

   

• 实现对象的序列化接口

  public class RedisObjectSerializer implements RedisSerializer<Object> {
  
    private Converter<Object, byte[]> serializer = new SerializingConverter();
    private Converter<byte[], Object> deserializer = new DeserializingConverter();
  
    static final byte[] EMPTY_ARRAY = new byte[0];
  
    public Object deserialize(byte[] bytes) {
      if (isEmpty(bytes)) {
        return null;
      }
  
      try {
        return deserializer.convert(bytes);
      } catch (Exception ex) {
        throw new SerializationException("Cannot deserialize", ex);
      }
    }
  
    public byte[] serialize(Object object) {
      if (object == null) {
        return EMPTY_ARRAY;
      }
  
      try {
        return serializer.convert(object);
      } catch (Exception ex) {
        return EMPTY_ARRAY;
      }
    }
  
    private boolean isEmpty(byte[] data) {
      return (data == null || data.length == 0);
    }
  }
   
  

  　　

• 配置针对User的RedisTemplate实例

  @Configuration
  public class RedisConfig {
  
      @Bean
      JedisConnectionFactory jedisConnectionFactory() {
          return new JedisConnectionFactory();
      }
  
      @Bean
      public RedisTemplate<String, User> redisTemplate(RedisConnectionFactory factory) {
          RedisTemplate<String, User> template = new RedisTemplate<String, User>();
          template.setConnectionFactory(jedisConnectionFactory());
          template.setKeySerializer(new StringRedisSerializer());
          template.setValueSerializer(new RedisObjectSerializer());
          return template;
      }
  
  
  }
   
  

  　　

• 完成了配置工作后，编写测试用例实验效果

  @RunWith(SpringJUnit4ClassRunner.class)
  @SpringApplicationConfiguration(Application.class)
  public class ApplicationTests {
  
  	@Autowired
  	private RedisTemplate<String, User> redisTemplate;
  
  	@Test
  	public void test() throws Exception {
  
  		// 保存对象
  		User user = new User("超人", 20);
  		redisTemplate.opsForValue().set(user.getUsername(), user);
  
  		user = new User("蝙蝠侠", 30);
  		redisTemplate.opsForValue().set(user.getUsername(), user);
  
  		user = new User("蜘蛛侠", 40);
  		redisTemplate.opsForValue().set(user.getUsername(), user);
  
  		Assert.assertEquals(20, redisTemplate.opsForValue().get("超人").getAge().longValue());
  		Assert.assertEquals(30, redisTemplate.opsForValue().get("蝙蝠侠").getAge().longValue());
  		Assert.assertEquals(40, redisTemplate.opsForValue().get("蜘蛛侠").getAge().longValue());
  
  	}
  
  }
  

  　　

  当然spring-data-redis中提供的数据操作远不止这些，本文仅作为在Spring Boot中使用redis时的配置参考，更多对于redis的操作使用，请参考Spring-data-redis Reference。

• 源码来源