在spring boot环境中使用fastjson + redis的高速缓存技术

因为项目需求，需要在spring boot环境中使用redis作数据缓存。之前的解决方案是参考的http://wiselyman.iteye.com/blog/2184884，具体使用的是Jackson2JsonRedisSerializer。但是使用后发现性能并不理想，一个简单的json请求就需要几百毫秒。

后来项目的json统一换成了fastjson，使用了FastJsonRedisSerializer后，性能大幅提升，一个请求通常只要10几毫秒。

1.添加redis、fastjson的支持

 <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-redis</artifactId>
 </dependency>
   <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>fastjson</artifactId>
        <version>1.2.31</version>
    </dependency>

2.在application.properties中配置redis

spring.redis.host=localhost
spring.redis.port=6379
spring.redis.pool.max-idle=8
spring.redis.pool.min-idle=0
spring.redis.pool.max-active=8
spring.redis.pool.max-wait=-1

3。在Application中

@SpringBootApplication
public class Application extends WebMvcConfigurerAdapter{
    public static void main(String[] args) {
        ParserConfig.getGlobalInstance().addAccept("com. mypackage.entity.");
        SpringApplication.run(Application.class,args);
    }

@Override
    public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
        super.configureMessageConverters(converters);

        FastJsonHttpMessageConverter4 converter = new FastJsonHttpMessageConverter4();
        FastJsonConfig config = new FastJsonConfig();
        config.setSerializerFeatures(SerializerFeature.WriteMapNullValue,SerializerFeature.PrettyFormat,SerializerFeature.WriteNullListAsEmpty);

        converter.setFastJsonConfig(config);

        converters.add(converter);

    }
}

　这里的ParserConfig.getGlobalInstance().addAccept是因为在fastjson 1.2.25之后的版本，autotype功能是受限的，需要添加白名单。具体参考https://github.com/alibaba/fastjson/wiki/enable_autotype。或者使用

ParserConfig.getGlobalInstance().setAutoTypeSupport(true); 

4。配置RedisConfig，具体代码如下：

@Configuration
@EnableCaching
public class RedisConfig extends CachingConfigurerSupport {
    @Bean
    public KeyGenerator wiselyKeyGenerator(){
        return new KeyGenerator() {
            @Override
            public Object generate(Object target, Method method, Object... params) {
                StringBuilder sb = new StringBuilder();
                sb.append(target.getClass().getName());
                sb.append(method.getName());
                for (Object obj : params) {
                    sb.append(obj.toString());
                }
                return sb.toString();
            }
        };

    }
    @Bean
    public CacheManager cacheManager(
            @SuppressWarnings("rawtypes") RedisTemplate redisTemplate) {
        return new RedisCacheManager(redisTemplate);
    }

    @Bean
    public RedisTemplate<String, String> redisTemplate(
            RedisConnectionFactory factory) {
        StringRedisTemplate template = new StringRedisTemplate(factory);
        FastJsonRedisSerializer<Object> serializer = new FastJsonRedisSerializer<>(Object.class);
        template.setValueSerializer(serializer);
        template.afterPropertiesSet();
        return template;
    }

    private static class FastJsonRedisSerializer<T> implements RedisSerializer<T> {

        private static final Charset DEFAULT_CHARSET = Charset.forName("UTF-8");

        private Class<T> clazz;

        public FastJsonRedisSerializer(Class<T> clazz) {
            this.clazz = clazz;
        }

        @Override
        public byte[] serialize(T t) throws SerializationException {
            if (t == null) {
                return new byte[0];
            }
            return JSON.toJSONString(t, SerializerFeature.WriteClassName).getBytes(DEFAULT_CHARSET);
        }

        @Override
        public T deserialize(byte[] bytes) throws SerializationException {
            if (bytes == null || bytes.length <= 0) {
                return null;
            }
            String str = new String(bytes, DEFAULT_CHARSET);
            return (T) JSON.parseObject(str, clazz);
        }
    }

}

这里的SerializerFeature.WriteClassName是必须的