调用org.apache.dubbo.rpc.support.RpcUtils#getReturnType引发NPE

[piliyouxia8987]

• [yes ] I have searched the issues of this repository and believe that this is not a duplicate.
• [ yes] I have checked the FAQ of this repository and believe that this is not a duplicate.

Environment

• Dubbo version: 2.7.8
• Operating System version: all
• Java version: 1.8.0_261

Steps to reproduce this issue

1. 调用返回值为void的Rpc方法

Pls. provide [GitHub address] to reproduce this issue.

Expected Result

What do you expected from the above steps？ 不引起空指针异常

Actual Result

抛空指针异常

What actually happens?

public static Class<?> getReturnType(Invocation invocation) {
        try {
            if (invocation != null && invocation.getInvoker() != null
                    && invocation.getInvoker().getUrl() != null
                    && invocation.getInvoker().getInterface() != GenericService.class
                    && !invocation.getMethodName().startsWith("$")) {
                String service = invocation.getInvoker().getUrl().getServiceInterface();
                if (StringUtils.isNotEmpty(service)) {
                    Method method = getMethodByService(invocation, service);
                    // method没有进行判空，直接调用，引发NPE
                    return method.getReturnType();
                }
            }
        } catch (Throwable t) {
            logger.warn(t.getMessage(), t);
        }
        return null;
    }

 private static Method getMethodByService(Invocation invocation, String service) throws NoSuchMethodException {
        Class<?> invokerInterface = invocation.getInvoker().getInterface();
        Class<?> cls = invokerInterface != null ? ReflectUtils.forName(invokerInterface.getClassLoader(), service)
                : ReflectUtils.forName(service);
        Method method = cls.getMethod(invocation.getMethodName(), invocation.getParameterTypes());
        if (method.getReturnType() == void.class) {
            // void时返回null
            return null;
        }
        return method;
    }

根据上边代码：

• Method method = getMethodByService(invocation, service);
• getMethodByService方法在返回值是void.class时，返回null
• method没有进行null判断，直接调用method.getReturnType(),导致空指针

If there is an exception, please attach the exception trace:

java.lang.NullPointerException: null
    at org.apache.dubbo.rpc.support.RpcUtils.getReturnType(RpcUtils.java:63)
    at org.apache.dubbo.monitor.dubbo.MetricsFilter.buildMethodName(MetricsFilter.java:137)
    at org.apache.dubbo.monitor.dubbo.MetricsFilter.reportMetrics(MetricsFilter.java:149)
    at org.apache.dubbo.monitor.dubbo.MetricsFilter.invoke(MetricsFilter.java:104)
    at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83)
    at com.skyeye.k12.teacher.common.filter.LogApacheDubboFilter.invoke(LogApacheDubboFilter.java:31)
    at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83)
    at org.apache.dubbo.rpc.filter.ExceptionFilter.invoke(ExceptionFilter.java:52)
    at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83)
    at com.alibaba.csp.sentinel.adapter.dubbo.SentinelDubboProviderFilter.invoke(SentinelDubboProviderFilter.java:73)
    at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83)
    at org.apache.dubbo.rpc.filter.TimeoutFilter.invoke(TimeoutFilter.java:46)
    at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83)
    at org.apache.dubbo.rpc.protocol.dubbo.filter.TraceFilter.invoke(TraceFilter.java:77)
    at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83)
    at com.koolearn.framework.monitor.dubbo.MicrometerMetricsFilter.invoke(MicrometerMetricsFilter.java:38)
    at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83)
    at org.apache.dubbo.monitor.support.MonitorFilter.invoke(MonitorFilter.java:89)
    at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83)
    at com.skyeye.k12.teacher.common.filter.LogApacheMDCClearDubboFilter.invoke(LogApacheMDCClearDubboFilter.java:19)
    at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83)
    at com.alibaba.dubbo.rpc.Invoker$CompatibleInvoker.invoke(Invoker.java:55)
    at net.dubboclub.catmonitor.CatTransaction.invoke(CatTransaction.java:37)
    at com.alibaba.dubbo.rpc.Filter.invoke(Filter.java:29)
    at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83)
    at org.apache.dubbo.rpc.filter.ContextFilter.invoke(ContextFilter.java:129)
    at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83)
    at org.apache.dubbo.rpc.filter.GenericFilter.invoke(GenericFilter.java:152)
    at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83)
    at org.apache.dubbo.rpc.filter.ClassLoaderFilter.invoke(ClassLoaderFilter.java:38)
    at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83)
    at org.apache.dubbo.rpc.filter.EchoFilter.invoke(EchoFilter.java:41)
    at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83)
    at org.apache.dubbo.rpc.protocol.injvm.InjvmInvoker.doInvoke(InjvmInvoker.java:63)
    at org.apache.dubbo.rpc.protocol.AbstractInvoker.invoke(AbstractInvoker.java:163)
    at org.apache.dubbo.rpc.protocol.AsyncToSyncInvoker.invoke(AsyncToSyncInvoker.java:52)
    at org.apache.dubbo.rpc.listener.ListenerInvokerWrapper.invoke(ListenerInvokerWrapper.java:78)
    at com.alibaba.dubbo.rpc.Invoker$CompatibleInvoker.invoke(Invoker.java:55)
    at net.dubboclub.catmonitor.AppNameAppendFilter.invoke(AppNameAppendFilter.java:16)
    at com.alibaba.dubbo.rpc.Filter.invoke(Filter.java:29)
    at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83)
    at com.alibaba.csp.sentinel.adapter.dubbo.DubboAppContextFilter.invoke(DubboAppContextFilter.java:43)
    at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83)
    at com.koolearn.framework.monitor.dubbo.MicrometerMetricsFilter.invoke(MicrometerMetricsFilter.java:38)
    at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83)
    at com.alibaba.csp.sentinel.adapter.dubbo.SentinelDubboConsumerFilter.invoke(SentinelDubboConsumerFilter.java:77)
    at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83)
    at org.apache.dubbo.monitor.support.MonitorFilter.invoke(MonitorFilter.java:89)
    at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83)
    at org.apache.dubbo.rpc.protocol.dubbo.filter.FutureFilter.invoke(FutureFilter.java:51)
    at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83)
    at com.alibaba.dubbo.rpc.Invoker$CompatibleInvoker.invoke(Invoker.java:55)
    at net.dubboclub.catmonitor.CatTransaction.invoke(CatTransaction.java:37)
    at com.alibaba.dubbo.rpc.Filter.invoke(Filter.java:29)
    at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83)
    at org.apache.dubbo.rpc.filter.ConsumerContextFilter.invoke(ConsumerContextFilter.java:69)
    at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83)
    at org.apache.dubbo.rpc.proxy.InvokerInvocationHandler.invoke(InvokerInvocationHandler.java:74)
    at org.apache.dubbo.common.bytecode.proxy11.processOffline(proxy11.java)

[longzhiwuing]

遇到同样的问题，这个bug也太明显了啊。。。。

[xiaoheng1]

let me have a look.

[AlbumenJ]

close #7626 via #7627