Java tutorial
/** * Copyright 2015 Netflix, Inc. * <p/> * 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 * <p/> * http://www.apache.org/licenses/LICENSE-2.0 * <p/> * 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.contrib.javanica.command; import com.netflix.hystrix.HystrixCollapser; import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand; import com.netflix.hystrix.contrib.javanica.utils.FallbackMethod; import com.netflix.hystrix.contrib.javanica.utils.MethodProvider; import org.apache.commons.lang3.Validate; import java.lang.reflect.Method; import java.util.Collection; import java.util.Collections; import static com.netflix.hystrix.contrib.javanica.cache.CacheInvocationContextFactory.createCacheRemoveInvocationContext; import static com.netflix.hystrix.contrib.javanica.cache.CacheInvocationContextFactory.createCacheResultInvocationContext; import static com.netflix.hystrix.contrib.javanica.utils.EnvUtils.isCompileWeaving; import static com.netflix.hystrix.contrib.javanica.utils.ajc.AjcUtils.getAjcMethodAroundAdvice; /** * Created by dmgcodevil. */ public class HystrixCommandBuilderFactory { // todo Add Cache private static final HystrixCommandBuilderFactory INSTANCE = new HystrixCommandBuilderFactory(); public static HystrixCommandBuilderFactory getInstance() { return INSTANCE; } private HystrixCommandBuilderFactory() { } public HystrixCommandBuilder create(MetaHolder metaHolder) { return create(metaHolder, Collections.<HystrixCollapser.CollapsedRequest<Object, Object>>emptyList()); } public HystrixCommandBuilder create(MetaHolder metaHolder, Collection<HystrixCollapser.CollapsedRequest<Object, Object>> collapsedRequests) { validateMetaHolder(metaHolder); return HystrixCommandBuilder.builder().setterBuilder(createGenericSetterBuilder(metaHolder)) .commandActions(createCommandActions(metaHolder)).collapsedRequests(collapsedRequests) .cacheResultInvocationContext(createCacheResultInvocationContext(metaHolder)) .cacheRemoveInvocationContext(createCacheRemoveInvocationContext(metaHolder)) .ignoreExceptions(metaHolder.getCommandIgnoreExceptions()) .executionType(metaHolder.getExecutionType()).build(); } private void validateMetaHolder(MetaHolder metaHolder) { Validate.notNull(metaHolder, "metaHolder is required parameter and cannot be null"); Validate.isTrue(metaHolder.isCommandAnnotationPresent(), "hystrixCommand annotation is absent"); } private GenericSetterBuilder createGenericSetterBuilder(MetaHolder metaHolder) { GenericSetterBuilder.Builder setterBuilder = GenericSetterBuilder.builder() .groupKey(metaHolder.getCommandGroupKey()).threadPoolKey(metaHolder.getThreadPoolKey()) .commandKey(metaHolder.getCommandKey()).collapserKey(metaHolder.getCollapserKey()) .commandProperties(metaHolder.getCommandProperties()) .threadPoolProperties(metaHolder.getThreadPoolProperties()) .collapserProperties(metaHolder.getCollapserProperties()); if (metaHolder.isCollapserAnnotationPresent()) { setterBuilder.scope(metaHolder.getHystrixCollapser().scope()); } return setterBuilder.build(); } private CommandActions createCommandActions(MetaHolder metaHolder) { CommandAction commandAction = createCommandAction(metaHolder); CommandAction fallbackAction = createFallbackAction(metaHolder); return CommandActions.builder().commandAction(commandAction).fallbackAction(fallbackAction).build(); } private CommandAction createCommandAction(MetaHolder metaHolder) { return new MethodExecutionAction(metaHolder.getObj(), metaHolder.getMethod(), metaHolder.getArgs(), metaHolder); } private CommandAction createFallbackAction(MetaHolder metaHolder) { FallbackMethod fallbackMethod = MethodProvider.getInstance().getFallbackMethod( metaHolder.getObj().getClass(), metaHolder.getMethod(), metaHolder.isExtendedFallback()); fallbackMethod.validateReturnType(metaHolder.getMethod()); CommandAction fallbackAction = null; if (fallbackMethod.isPresent()) { Method fMethod = fallbackMethod.getMethod(); if (fallbackMethod.isCommand()) { fMethod.setAccessible(true); HystrixCommand hystrixCommand = fMethod.getAnnotation(HystrixCommand.class); MetaHolder fmMetaHolder = MetaHolder.builder().obj(metaHolder.getObj()).method(fMethod) .ajcMethod(getAjcMethod(metaHolder.getObj(), fMethod)).args(metaHolder.getArgs()) .fallback(true).defaultCollapserKey(metaHolder.getDefaultCollapserKey()) .fallbackMethod(fMethod).extendedFallback(fallbackMethod.isExtended()) .fallbackExecutionType(fallbackMethod.getExecutionType()) .extendedParentFallback(metaHolder.isExtendedFallback()) .observable(ExecutionType.OBSERVABLE == fallbackMethod.getExecutionType()) .defaultCommandKey(fMethod.getName()).defaultGroupKey(metaHolder.getDefaultGroupKey()) .defaultThreadPoolKey(metaHolder.getDefaultThreadPoolKey()) .defaultProperties(metaHolder.getDefaultProperties().orNull()) .hystrixCollapser(metaHolder.getHystrixCollapser()) .observableExecutionMode(hystrixCommand.observableExecutionMode()) .hystrixCommand(hystrixCommand).build(); fallbackAction = new LazyCommandExecutionAction(fmMetaHolder); } else { MetaHolder fmMetaHolder = MetaHolder.builder().obj(metaHolder.getObj()).method(fMethod) .fallbackExecutionType(ExecutionType.SYNCHRONOUS) .extendedFallback(fallbackMethod.isExtended()) .extendedParentFallback(metaHolder.isExtendedFallback()).ajcMethod(null) // if fallback method isn't annotated with command annotation then we don't need to get ajc method for this .args(metaHolder.getArgs()).build(); fallbackAction = new MethodExecutionAction(fmMetaHolder.getObj(), fMethod, fmMetaHolder.getArgs(), fmMetaHolder); } } return fallbackAction; } private Method getAjcMethod(Object target, Method fallback) { if (isCompileWeaving()) { return getAjcMethodAroundAdvice(target.getClass(), fallback); } return null; } }