@SentinelResource注解使用方法总结

@SentinelResource注解总结

• @SentinelResource 用于定义资源，并提供可选的异常处理和 fallback 配置项。其主要参数如下:

  • 属性	作用
    value	资源名称
    entryType	entry类型，标记流量的方向，取值IN/OUT，默认是OUT
    blockHandler	处理BlockException的函数名称,函数要求：1. 必须是 public2. 返回类型 参数与原方法一致3. 默认需和原方法在同一个类中。若希望使用其他类 的函数，可配置blockHandlerClass ，并指定blockHandlerClass里面的 方法。
    blockHandlerClass	存放blockHandler的类,对应的处理函数必须static修饰。
    fallback	用于在抛出异常的时候提供fallback处理逻辑。fallback函数可以针对所 有类型的异常（除了exceptionsToIgnore 里面排除掉的异常类型）进行 处理。函数要求：1. 返回类型与原方法一致2. 参数类型需要和原方法相 匹配3. 默认需和原方法在同一个类中。若希望使用其他类的函数，可配 置fallbackClass ，并指定fallbackClass里面的方法。
    fallbackClass	存放fallback的类。对应的处理函数必须static修饰。
    defaultFallback	用于通用的 fallback 逻辑。默认fallback函数可以针对所有类型的异常进 行处理。若同时配置了 fallback 和 defaultFallback，以fallback为准。函 数要求：1. 返回类型与原方法一致2. 方法参数列表为空，或者有一个 Throwable 类型的参数。3. 默认需要和原方法在同一个类中。若希望使 用其他类的函数，可配置fallbackClass ，并指定 fallbackClass 里面的方 法。
    exceptionsToIgnore	指定排除掉哪些异常。排除的异常不会计入异常统计，也不会进入 fallback逻辑，而是原样抛出
    exceptionsToTrace	需要trace的异常

  • 在定义了资源点之后，我们可以通过Dashboard来设置限流和降级策略来对资源点进行保护。同时还能通过@SentinelResource来指定出现异常时的处理策略

定义限流和降级后的处理方法

blockHandler fallback

• blockHandler 指定发生BlockException时进入的方法
• fallback 指定发生异常都会到这里，而且你可以打印具体的异常信息常用

@ApiOperation(value = "测试SentinelResource定义资源，异常", httpMethod = "GET")
@RequestMapping("/message6")
public String message6(String name, Integer age) {
     
    sentinelService.SentinelResource(name, age);
    return "message6";
}

@Slf4j
@Service
public class SentinelService {
     
    int i = 0;

    /**
     *	自己添加一个运行时异常实验效果
     */
    @SentinelResource(value = "message6", blockHandler = "blockHandler", fallback = "fallback")
    public String SentinelResource(String name, Integer age) {
     
        i++;
        if (i % 3 == 0) {
     
            throw new RuntimeException();
        }
        log.info(name, age);
        return "SentinelResource success";
    }


    public String blockHandler(String name, Integer age,BlockException ex) {
     
        log.error("BlockException异常:{}", ex.getMessage());
        return "BlockException，接口被限流或降级";
    }

    public String fallback(String name, Integer age,Throwable throwable) {
     
        log.error("fallback异常：{}", throwable);
        return "接口发生throwable异常";
    }

}

sentinel定义限流、降级

• 这个步骤我就不写了不会的可以去参考之前的文章：SpringCloud Alibaba Sentinel

测试效果日志

2021-02-04 14:05:59.249  INFO 24868 --- [nio-9001-exec-2] c.z.a.s.controller.SentinelService       : 1
2021-02-04 14:05:59.464 ERROR 24868 --- [nio-9001-exec-3] c.z.a.s.controller.SentinelService       : BlockException异常:null
2021-02-04 14:05:59.649 ERROR 24868 --- [nio-9001-exec-4] c.z.a.s.controller.SentinelService       : BlockException异常:null
2021-02-04 14:05:59.841 ERROR 24868 --- [nio-9001-exec-5] c.z.a.s.controller.SentinelService       : BlockException异常:null
2021-02-04 14:06:00.070 ERROR 24868 --- [nio-9001-exec-6] c.z.a.s.controller.SentinelService       : fallback异常：{}

java.lang.RuntimeException: null
	at com.zxx.alibaba.sentinel.controller.SentinelService.SentinelResource(SentinelService.java:30) ~[classes/:na]
	at com.zxx.alibaba.sentinel.controller.SentinelService$$FastClassBySpringCGLIB$$a947b896.invoke() ~[classes/:na]
	at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218) [spring-core-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:769) [spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163) ~[spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:747) [spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:88) ~[spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at com.alibaba.csp.sentinel.annotation.aspectj.SentinelResourceAspect.invokeResourceWithSentinel(SentinelResourceAspect.java:57) ~[sentinel-annotation-aspectj-1.8.0.jar:na]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_191]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_191]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_191]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_191]
	at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:644) ~[spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:633) ~[spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:70) ~[spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:175) ~[spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:747) [spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:93) [spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:747) [spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:689) [spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at com.zxx.alibaba.sentinel.controller.SentinelService$$EnhancerBySpringCGLIB$$121cb23d.SentinelResource() [classes/:na]
	at com.zxx.alibaba.sentinel.controller.DemoController1.message6(DemoController1.java:69) [classes/:na]
	at com.zxx.alibaba.sentinel.controller.DemoController1$$FastClassBySpringCGLIB$$18d1f0d7.invoke() [classes/:na]
	at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218) [spring-core-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:769) [spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163) ~[spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:747) [spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:93) [spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:747) [spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:689) [spring-aop-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at com.zxx.alibaba.sentinel.controller.DemoController1$$EnhancerBySpringCGLIB$$675c0ba0.message6() [classes/:na]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_191]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_191]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_191]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_191]
	at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190) [spring-web-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) [spring-web-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:106) [spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:888) [spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:793) [spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) [spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040) [spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) [spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) [spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) [spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) [tomcat-embed-core-9.0.27.jar:9.0.27]
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) [spring-webmvc-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) [tomcat-embed-core-9.0.27.jar:9.0.27]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) [tomcat-embed-core-9.0.27.jar:9.0.27]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.27.jar:9.0.27]
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) [tomcat-embed-websocket-9.0.27.jar:9.0.27]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-9.0.27.jar:9.0.27]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.27.jar:9.0.27]
	at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) [spring-web-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) [spring-web-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-9.0.27.jar:9.0.27]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.27.jar:9.0.27]
	at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) [spring-web-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) [spring-web-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-9.0.27.jar:9.0.27]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.27.jar:9.0.27]
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) [spring-web-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) [spring-web-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-9.0.27.jar:9.0.27]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.27.jar:9.0.27]
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) [tomcat-embed-core-9.0.27.jar:9.0.27]
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-9.0.27.jar:9.0.27]
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:526) [tomcat-embed-core-9.0.27.jar:9.0.27]
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) [tomcat-embed-core-9.0.27.jar:9.0.27]
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.27.jar:9.0.27]
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) [tomcat-embed-core-9.0.27.jar:9.0.27]
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) [tomcat-embed-core-9.0.27.jar:9.0.27]
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408) [tomcat-embed-core-9.0.27.jar:9.0.27]
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-9.0.27.jar:9.0.27]
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:861) [tomcat-embed-core-9.0.27.jar:9.0.27]
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1579) [tomcat-embed-core-9.0.27.jar:9.0.27]
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.27.jar:9.0.27]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_191]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_191]
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.27.jar:9.0.27]
	at java.lang.Thread.run(Thread.java:748) [na:1.8.0_191]

blockHandlerClass fallbackClass

• 将限流和降级方法外置到单独的类中
• 注意如果使用blockHandlerClass、fallbackClass一定要注意要加上blockHandler和fallback要和处理类里面的方法名保持一直不然会找不到的！

@SentinelResource(value = "message6",
            blockHandlerClass = BlockHandlerClass.class, blockHandler = "blockHandlerMethod",
            fallbackClass = FallbackClass.class, fallback = "fallbackMethod"
    )
public String SentinelResource(String name, Integer age) {
     
    i++;
    if (i % 3 == 0) {
     
        throw new RuntimeException();
    }
    log.info(name, age);
    return "SentinelResource success";
}

• fallbackClass

@Slf4j
public class FallbackClass {
     

    public static String fallbackMethod(String name, Integer age, Throwable throwable) {
     
        log.error("fallback异常：{}", throwable);
        return "接口发生throwable异常";
    }
}

• blockHandlerClass

@Slf4j
public class BlockHandlerClass {
     

    public static String blockHandlerMethod(String name, Integer age, BlockException ex) {
     
        log.error("BlockException异常:{}", ex.getMessage());
        return "BlockException，接口被限流或降级";
    }

}

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