Spring Cache 应用

这节我们主要从应用的角度上，讲解下spring Cache在项目的应用。

1、首先引入spring cache的jar包，最好引入下第三方的缓存jar包

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-cache</artifactId>
</dependency>

<dependency>
    <groupId>com.google.guava</groupId>
    <artifactId>guava</artifactId>
    <version>28.0-jre</version>
</dependency>

 2、开启缓存注解--EnableCaching

@EnableCaching
public class Application {

    public static void main(String[] args) {
//        aes();
//        testJson();
        SpringApplication.run(Application.class, args);
    }
}

3、自定义CacheManager  

@Configuration
public class CacheConfig {


    @Bean
    @Primary
    public GuavaCacheManager guavaCacheManager() {
        GuavaCacheManager guavaCacheManager = new GuavaCacheManager() {
            /**
             * 设置数量限制、超时时间
             * @param name
             * @return
             */
            @Override
            protected com.google.common.cache.Cache<Object, Object> createNativeGuavaCache(String name) {
                return CacheBuilder.newBuilder()
                        .maximumSize(1000)
                        .expireAfterWrite(24, TimeUnit.HOURS)
                        .build();
            }
        };
        guavaCacheManager.setAllowNullValues(false);
        return guavaCacheManager;
    }

}

4、缓存使用

    @GetMapping
    @ApiOperation("")
    @Cacheable(key = "'templates'", cacheNames = "templates")
    public List<Template> obtain() throws Exception {
        String result = restService.getInfo(tUrl, HttpMethod.GET, headService.headers(null), false, false);
        JsonNode root = mapper.readTree(result);
        JavaType javaType = mapper.getTypeFactory().constructParametricType(List.class, Template.class);
        List<Template> list = (List<Template>) mapper.readValue(root.get("root").get("template").toString(), javaType);
        return list;
    }

 上述代码在第一次的时候，会执行方法中的逻辑，当第二次的时候，变回通过缓存进行获取。