基于openfeign+sentinel的统一降级服务代码

package com.sean.han.common.sentinel.feign; import com.alibaba.cloud.sentinel.feign.SentinelContractHolder; import com.alibaba.cloud.sentinel.feign.SentinelInvocationHandler; import com.alibaba.csp.sentinel.Entry; import com.alibaba.csp.sentinel.EntryType; import com.alibaba.csp.sentinel.SphU; import com.alibaba.csp.sentinel.Tracer; import com.alibaba.csp.sentinel.context.ContextUtil; import com.alibaba.csp.sentinel.slots.block.BlockException; import com.sean.han.common.core.util.R; import feign.Feign; import feign.InvocationHandlerFactory; import feign.MethodMetadata; import feign.Target; import lombok.extern.slf4j.Slf4j; import org.springframework.cloud.openfeign.FallbackFactory; import java.lang.reflect.InvocationHandler; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import java.lang.reflect.Proxy; import java.util.LinkedHashMap; import java.util.Map; import static feign.Util.checkNotNull; /** * @Author: Sean * @Date: 2023/11/19 11:20 * @Description: 重写 {@link com.alibaba.cloud.sentinel.feign.SentinelInvocationHandler} 支持自动降级注入 */ @Slf4j public class HanSentinelInvocationHandler implements InvocationHandler { public static final String EQUALS = "equals"; public static final String HASH_CODE = "hashCode"; public static final String TO_STRING = "toString"; private final Target<?> target; private final Map<Method, InvocationHandlerFactory.MethodHandler> dispatch; private FallbackFactory fallbackFactory; private Map<Method, Method> fallbackMethodMap; private boolean autoFallback; HanSentinelInvocationHandler(Target<?> target, Map<Method, InvocationHandlerFactory.MethodHandler> dispatch, FallbackFactory fallbackFactory, boolean autoFallback) { this.target = checkNotNull(target, "target"); this.dispatch = checkNotNull(dispatch, "dispatch"); this.fallbackFactory = fallbackFactory; this.fallbackMethodMap = toFallbackMethod(dispatch); this.autoFallback = autoFallback; } HanSentinelInvocationHandler(Target<?> target, Map<Method, InvocationHandlerFactory.MethodHandler> dispatch, boolean autoFallback) { this.target = checkNotNull(target, "target"); this.dispatch = checkNotNull(dispatch, "dispatch"); this.autoFallback = autoFallback; } @Override public Object invoke(final Object proxy, final Method method, final Object[] args) throws Throwable { if (EQUALS.equals(method.getName())) { try { Object otherHandler = args.length > 0 && args[0] != null ? Proxy.getInvocationHandler(args[0]) : null; return equals(otherHandler); } catch (IllegalArgumentException e) { return false; } } else if (HASH_CODE.equals(method.getName())) { return hashCode(); } else if (TO_STRING.equals(method.getName())) { return toString(); } Object result; InvocationHandlerFactory.MethodHandler methodHandler = this.dispatch.get(method); // only handle by HardCodedTarget if (target instanceof Target.HardCodedTarget) { Target.HardCodedTarget hardCodedTarget = (Target.HardCodedTarget) target; MethodMetadata methodMetadata = SentinelContractHolder.METADATA_MAP .get(hardCodedTarget.type().getName() + Feign.configKey(hardCodedTarget.type(), method)); // resource default is HttpMethod:protocol://url if (methodMetadata == null) { result = methodHandler.invoke(args); } else { String resourceName = methodMetadata.template().method().toUpperCase() + ":" + hardCodedTarget.url() + methodMetadata.template().path(); Entry entry = null; try { ContextUtil.enter(resourceName); entry = SphU.entry(resourceName, EntryType.OUT, 1, args); result = methodHandler.invoke(args); } catch (Throwable ex) { // fallback handle if (!BlockException.isBlockException(ex)) { Tracer.trace(ex); } if (fallbackFactory != null) { try { Object fallbackResult = fallbackMethodMap.get(method).invoke(fallbackFactory.create(ex), args); return fallbackResult; } catch (IllegalAccessException e) { // shouldn't happen as method is public due to being an // interface throw new AssertionError(e); } catch (InvocationTargetException e) { throw new AssertionError(e.getCause()); } } else { //没有自定义降级处理，如果自动降级且返回格式是R，则进行统一降级处理 if (autoFallback && method.getReturnType().equals(R.class)) { String failMsg = "远程调用" + method.getDeclaringClass().getName() + "." + method.getName() + "异常！"; log.error(failMsg); log.error(ex.getMessage(), ex); return R.failed(failMsg); } throw ex; } } finally { if (entry != null) { entry.exit(1, args); } ContextUtil.exit(); } } } else { // other target type using default strategy result = methodHandler.invoke(args); } return result; } @Override public boolean equals(Object obj) { if (obj instanceof SentinelInvocationHandler) { HanSentinelInvocationHandler other = (HanSentinelInvocationHandler) obj; return target.equals(other.target); } return false; } @Override public int hashCode() { return target.hashCode(); } @Override public String toString() { return target.toString(); } static Map<Method, Method> toFallbackMethod(Map<Method, InvocationHandlerFactory.MethodHandler> dispatch) { Map<Method, Method> result = new LinkedHashMap<>(); for (Method method : dispatch.keySet()) { method.setAccessible(true); result.put(method, method); } return result; } }