/**
* Copyright 2012 Netflix, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.netflix.hystrix.examples.basic;
import static org.junit.Assert.*;
import org.junit.Test;
import com.netflix.hystrix.HystrixCommand;
import com.netflix.hystrix.HystrixCommandGroupKey;
import com.netflix.hystrix.strategy.concurrency.HystrixRequestContext;
/**
* Sample {@link HystrixCommand} showing how implementing the {@link #getCacheKey()} method
* enables request caching for eliminating duplicate calls within the same request context.
*/
public class CommandUsingRequestCache extends HystrixCommand<Boolean> {
private final int value;
protected CommandUsingRequestCache(int value) {
super(HystrixCommandGroupKey.Factory.asKey("ExampleGroup"));
this.value = value;
}
@Override
protected Boolean run() {
return value == 0 || value % 2 == 0;
}
@Override
protected String getCacheKey() {
return String.valueOf(value);
}
public static class UnitTest {
@Test
public void testWithoutCacheHits() {
HystrixRequestContext context = HystrixRequestContext.initializeContext();
try {
assertTrue(new CommandUsingRequestCache(2).execute());
assertFalse(new CommandUsingRequestCache(1).execute());
assertTrue(new CommandUsingRequestCache(0).execute());
assertTrue(new CommandUsingRequestCache(58672).execute());
} finally {
context.shutdown();
}
}
@Test
public void testWithCacheHits() {
HystrixRequestContext context = HystrixRequestContext.initializeContext();
try {
CommandUsingRequestCache command2a = new CommandUsingRequestCache(2);
CommandUsingRequestCache command2b = new CommandUsingRequestCache(2);
assertTrue(command2a.execute());
// this is the first time we've executed this command with the value of "2" so it should not be from cache
assertFalse(command2a.isResponseFromCache());
assertTrue(command2b.execute());
// this is the second time we've executed this command with the same value so it should return from cache
assertTrue(command2b.isResponseFromCache());
} finally {
context.shutdown();
}
// start a new request context
context = HystrixRequestContext.initializeContext();
try {
CommandUsingRequestCache command3b = new CommandUsingRequestCache(2);
assertTrue(command3b.execute());
// this is a new request context so this should not come from cache
assertFalse(command3b.isResponseFromCache());
} finally {
context.shutdown();
}
}
}
}