Hystrix缓存策略

一 命令执行流程

二 测试代码

package org.crazyit.cloud.cache;

import com.netflix.hystrix.HystrixCommand;
import com.netflix.hystrix.HystrixCommandGroupKey;
import com.netflix.hystrix.HystrixCommandKey;
import com.netflix.hystrix.HystrixRequestCache;
import com.netflix.hystrix.HystrixThreadPoolKey;
import com.netflix.hystrix.HystrixCommand.Setter;
import com.netflix.hystrix.strategy.concurrency.HystrixConcurrencyStrategy;
import com.netflix.hystrix.strategy.concurrency.HystrixConcurrencyStrategyDefault;
import com.netflix.hystrix.strategy.concurrency.HystrixRequestContext;

public class CacheMain {

    public static void main(String[] args) {
        HystrixRequestContext ctx = HystrixRequestContext.initializeContext();
        String key = "cache-key";
        CacheCommand c1 = new CacheCommand(key);
        CacheCommand c2 = new CacheCommand(key);
        CacheCommand c3 = new CacheCommand(key);
        c1.execute();
        c2.execute();
        c3.execute();
        
        System.out.println("命令c1，是否读取缓存：" + c1.isResponseFromCache());
        System.out.println("命令c2，是否读取缓存：" + c2.isResponseFromCache());
        System.out.println("命令c3，是否读取缓存：" + c3.isResponseFromCache());
        
        HystrixRequestCache cache = HystrixRequestCache.getInstance(HystrixCommandKey.Factory.asKey("MyCommandKey"),
                HystrixConcurrencyStrategyDefault.getInstance());
        cache.clear(key);
        CacheCommand c4 = new CacheCommand(key);
        c4.execute();
        System.out.println("命令c4，是否读取缓存：" + c4.isResponseFromCache());
        
        ctx.shutdown();
    }

    static class CacheCommand extends HystrixCommand<String> {
        private String cacheKey;
        public CacheCommand(String cacheKey) {
            super(Setter.withGroupKey(
                    HystrixCommandGroupKey.Factory.asKey("TestGroupKey"))
                    .andCommandKey(
                            HystrixCommandKey.Factory.asKey("MyCommandKey")));
            this.cacheKey = cacheKey;
        }
        @Override
        protected String run() throws Exception {
            System.out.println("执行方法");
            return "";
        }
        @Override
        protected String getFallback() {
            System.out.println("执行回退");
            return "";
        }
        @Override
        protected String getCacheKey() {
            return this.cacheKey;
        }
        
    }
}

三 测试结果

执行方法

命令c1，是否读取缓存：false

命令c2，是否读取缓存：true

命令c3，是否读取缓存：true

执行方法

命令c4，是否读取缓存：false