/*
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* Copyright 2013-2018 the original author or authors.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* https://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package org.springblade.core.cloud.sentinel;
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import com.alibaba.cloud.sentinel.feign.SentinelContractHolder;
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import feign.Contract;
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import feign.Feign;
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import feign.InvocationHandlerFactory;
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import feign.Target;
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import org.springframework.cloud.openfeign.FallbackFactory;
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import lombok.SneakyThrows;
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import org.springblade.core.cloud.feign.BladeFallbackFactory;
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import org.springframework.beans.BeansException;
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import org.springframework.cloud.openfeign.FeignClient;
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import org.springframework.cloud.openfeign.FeignContext;
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import org.springframework.context.ApplicationContext;
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import org.springframework.context.ApplicationContextAware;
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import org.springframework.core.annotation.AnnotationUtils;
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import org.springframework.util.StringUtils;
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import java.lang.reflect.InvocationHandler;
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import java.lang.reflect.Method;
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import java.util.Map;
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/**
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* feign集成sentinel自动配置
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* 重写 {@link com.alibaba.cloud.sentinel.feign.SentinelFeign} 适配最新API
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*
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* @author Chill
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*/
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public class BladeFeignSentinel {
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public static Builder builder() {
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return new Builder();
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}
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public static final class Builder extends Feign.Builder implements ApplicationContextAware {
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private Contract contract = new Contract.Default();
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private ApplicationContext applicationContext;
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private FeignContext feignContext;
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@Override
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public Feign.Builder invocationHandlerFactory(
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InvocationHandlerFactory invocationHandlerFactory) {
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throw new UnsupportedOperationException();
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}
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@Override
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public Builder contract(Contract contract) {
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this.contract = contract;
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return this;
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}
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@Override
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public Feign build() {
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super.invocationHandlerFactory(new InvocationHandlerFactory() {
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@SneakyThrows
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@Override
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public InvocationHandler create(Target target, Map<Method, MethodHandler> dispatch) {
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// 注解取值以避免循环依赖的问题
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FeignClient feignClient = AnnotationUtils.findAnnotation(target.type(), FeignClient.class);
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Class fallback = feignClient.fallback();
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Class fallbackFactory = feignClient.fallbackFactory();
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String contextId = feignClient.contextId();
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if (!StringUtils.hasText(contextId)) {
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contextId = feignClient.name();
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}
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Object fallbackInstance;
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FallbackFactory fallbackFactoryInstance;
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// 判断fallback类型
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if (void.class != fallback) {
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fallbackInstance = getFromContext(contextId, "fallback", fallback, target.type());
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return new BladeSentinelInvocationHandler(target, dispatch, new FallbackFactory.Default(fallbackInstance));
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}
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if (void.class != fallbackFactory) {
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fallbackFactoryInstance = (FallbackFactory) getFromContext(contextId, "fallbackFactory", fallbackFactory, FallbackFactory.class);
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return new BladeSentinelInvocationHandler(target, dispatch, fallbackFactoryInstance);
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}
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// 默认fallbackFactory
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BladeFallbackFactory bladeFallbackFactory = new BladeFallbackFactory(target);
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return new BladeSentinelInvocationHandler(target, dispatch, bladeFallbackFactory);
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}
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private Object getFromContext(String name, String type, Class fallbackType, Class targetType) {
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Object fallbackInstance = feignContext.getInstance(name, fallbackType);
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if (fallbackInstance == null) {
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throw new IllegalStateException(
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String.format("No %s instance of type %s found for feign client %s",
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type, fallbackType, name)
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);
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}
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if (!targetType.isAssignableFrom(fallbackType)) {
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throw new IllegalStateException(
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String.format("Incompatible %s instance. Fallback/fallbackFactory of type %s is not assignable to %s for feign client %s",
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type, fallbackType, targetType, name)
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);
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}
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return fallbackInstance;
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}
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});
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super.contract(new SentinelContractHolder(contract));
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return super.build();
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}
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@Override
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public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
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this.applicationContext = applicationContext;
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feignContext = this.applicationContext.getBean(FeignContext.class);
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}
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}
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}
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