WIP - initial code

anjeyy · anjeyy · commit 0511a5c598f5 · 2021-01-10T10:17:38.000+01:00
diff --git a/docs/en/index.md b/docs/en/index.md
@@ -1,9 +1,9 @@
 # gRPC-Spring-Boot-Starter Documentation
 
 gRPC-spring-boot-starter combines [google's open-source high performance RPC-framework](https://grpc.io) with
-[spring boot's ease of setup](https://spring.io/projects/spring-boot).
-This project simplifies the gRPC-server/client setup to adding one dependency to your project and adding a single
-annotation to your service class / client (stub) field.
+[spring boot's ease of setup](https://spring.io/projects/spring-boot). 
+This project simplifies the gRPC-server/client setup to adding one dependency to your project and adding a single 
+annotation to your service class / client (stub) field. 
 The features of this library are meant to complement your experience with gRPC and still allow you to do any
 customization you need for your project.
 
@@ -12,6 +12,7 @@ customization you need for your project.
 - Server
   - [Getting Started](server/getting-started.md)
   - [Configuration](server/configuration.md)
+  - [Exception Handling](server/exception-handling.md)
   - [Contextual Data / Scoped Beans](server/contextual-data.md)
   - [Testing the Service](server/testing.md)
   - [Security](server/security.md)
diff --git a/docs/en/server/configuration.md b/docs/en/server/configuration.md
@@ -17,6 +17,7 @@ This section describes how you can configure your grpc-spring-boot-starter appli
 
 - [Getting Started](getting-started.md)
 - *Configuration*
+- [Exception Handling](exception-handling.md)
 - [Contextual Data / Scoped Beans](contextual-data.md)
 - [Testing the Service](testing.md)
 - [Security](security.md)
@@ -121,6 +122,7 @@ public GrpcServerConfigurer keepAliveServerConfigurer() {
 
 - [Getting Started](getting-started.md)
 - *Configuration*
+- [Exception Handling](exception-handling.md)  
 - [Contextual Data / Scoped Beans](contextual-data.md)
 - [Testing the Service](testing.md)
 - [Security](security.md)
diff --git a/docs/en/server/contextual-data.md b/docs/en/server/contextual-data.md
@@ -13,6 +13,7 @@ This section describes how you can store contextual / per request data.
 
 - [Getting Started](getting-started.md)
 - [Configuration](configuration.md)
+- [Exception Handling](exception-handling.md)  
 - *Contextual Data / Scoped Beans*
 - [Testing the Service](testing.md)
 - [Security](security.md)
@@ -61,6 +62,7 @@ public void grpcMethod(Request request, StreamObserver<Response> responseObserve
 
 - [Getting Started](getting-started.md)
 - [Configuration](configuration.md)
+- [Exception Handling](exception-handling.md)  
 - *Contextual Data / Scoped Beans*
 - [Testing the Service](testing.md)
 - [Security](security.md)
diff --git a/docs/en/server/exception-handling.md b/docs/en/server/exception-handling.md
@@ -0,0 +1,36 @@
+# Exception Handling inside GrpcService
+
+[<- Back to Index](../index.md)
+
+This section describes how you can handle exceptions inside GrpcService layer without cluttering up your code.
+
+## Table of Contents <!-- omit in toc -->
+
+- [A Word of Warning](#a-word-of-warning)
+- [grpcRequest Scope](#grpcrequest-scope)
+
+## Additional Topics <!-- omit in toc -->
+
+- [Getting Started](getting-started.md)
+- [Configuration](configuration.md)
+- [Contextual Data](contextual-data.md)
+- *Exception Handling*
+- [Testing the Service](testing.md)
+- [Security](security.md)
+
+## TODO ...
+
+> TODO ...
+
+## Additional Topics <!-- omit in toc -->
+
+- [Getting Started](getting-started.md)
+- [Configuration](configuration.md)
+- [Contextual Data](contextual-data.md)
+- *Exception Handling*
+- [Testing the Service](testing.md)
+- [Security](security.md)
+
+----------
+
+[<- Back to Index](../index.md)
diff --git a/docs/en/server/getting-started.md b/docs/en/server/getting-started.md
@@ -18,6 +18,7 @@ This section describes the steps necessary to convert your application into a gr
 
 - *Getting started*
 - [Configuration](configuration.md)
+- [Exception Handling](exception-handling.md)  
 - [Contextual Data / Scoped Beans](contextual-data.md)
 - [Testing the Service](testing.md)
 - [Security](security.md)
@@ -316,6 +317,7 @@ See [here](testing.md#grpcurl) for `gRPCurl` example command output and addition
 
 - *Getting Started*
 - [Configuration](configuration.md)
+- [Exception Handling](exception-handling.md)  
 - [Contextual Data / Scoped Beans](contextual-data.md)
 - [Testing the Service](testing.md)
 - [Security](security.md)
diff --git a/docs/en/server/security.md b/docs/en/server/security.md
@@ -19,6 +19,7 @@ We strongly recommend enabling at least transport layer security.
 
 - [Getting Started](getting-started.md)
 - [Configuration](configuration.md)
+- [Exception Handling](exception-handling.md)  
 - [Contextual Data / Scoped Beans](contextual-data.md)
 - [Testing the Service](testing.md)
 - *Security*
@@ -279,6 +280,7 @@ public void methodX(Request request, StreamObserver<Response> responseObserver)
 
 - [Getting Started](getting-started.md)
 - [Configuration](configuration.md)
+- [Exception Handling](exception-handling.md)  
 - [Contextual Data / Scoped Beans](contextual-data.md)
 - [Testing the Service](testing.md)
 - *Security*
diff --git a/docs/en/server/testing.md b/docs/en/server/testing.md
@@ -22,6 +22,7 @@ Please refer to [Tests with Grpc-Stubs](../client/testing.md).
 
 - [Getting Started](getting-started.md)
 - [Configuration](configuration.md)
+- [Exception Handling](exception-handling.md)  
 - [Contextual Data / Scoped Beans](contextual-data.md)
 - *Testing the Service*
 - [Security](security.md)
@@ -368,6 +369,7 @@ For more information regarding `gRPCurl` please refer to their [official documen
 
 - [Getting Started](getting-started.md)
 - [Configuration](configuration.md)
+- [Exception Handling](exception-handling.md)  
 - [Contextual Data / Scoped Beans](contextual-data.md)
 - *Testing the Service*
 - [Security](security.md)
diff --git a/grpc-server-spring-boot-autoconfigure/src/main/java/net/devh/boot/grpc/server/autoconfigure/GrpcServerAutoConfiguration.java b/grpc-server-spring-boot-autoconfigure/src/main/java/net/devh/boot/grpc/server/autoconfigure/GrpcServerAutoConfiguration.java
@@ -108,6 +108,8 @@ public GrpcServiceDiscoverer defaultGrpcServiceDiscoverer() {
         return new AnnotationGrpcServiceDiscoverer();
     }
 
+    // TODO eventually insert @Conditional
+
     @ConditionalOnMissingBean
     @Bean
     public HealthStatusManager healthStatusManager() {
diff --git a/grpc-server-spring-boot-autoconfigure/src/main/java/net/devh/boot/grpc/server/service/exceptionhandling/GrpcExceptionAspect.java b/grpc-server-spring-boot-autoconfigure/src/main/java/net/devh/boot/grpc/server/service/exceptionhandling/GrpcExceptionAspect.java
@@ -0,0 +1,141 @@
+/*
+ * Copyright (c) 2016-2020 Michael Zhang <yidongnan@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated
+ * documentation files (the "Software"), to deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+ * WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+package net.devh.boot.grpc.server.service.exceptionhandling;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.lang.reflect.Parameter;
+import java.util.Map.Entry;
+import java.util.Optional;
+
+import org.aspectj.lang.JoinPoint;
+import org.aspectj.lang.annotation.AfterThrowing;
+import org.aspectj.lang.annotation.Aspect;
+import org.aspectj.lang.annotation.Pointcut;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
+import org.springframework.stereotype.Component;
+
+import io.grpc.stub.StreamObserver;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+
+/**
+ * Exception handling for thrown {@link RuntimeException} inside gRPC service classes, which implements
+ * {@link io.grpc.BindableService}.
+ */
+@Slf4j
+@Aspect
+@Component
+@RequiredArgsConstructor
+@ConditionalOnBean(annotation = GrpcServiceAdvice.class)
+public class GrpcExceptionAspect {
+
+    private final GrpcExceptionHandlerMethodResolver exceptionHandlerMethodResolver;
+
+    private Throwable exception;
+    private Method mappedMethod;
+    private Object instanceOfMappedMethod;
+
+
+    @Pointcut("within(@net.devh.boot.grpc.server.service.GrpcService *)")
+    void grpcServiceAnnotatedPointcut() {}
+
+    @Pointcut("within(io.grpc.BindableService+)")
+    void implementedBindableServicePointcut() {}
+
+    @AfterThrowing(
+            pointcut = "grpcServiceAnnotatedPointcut() && implementedBindableServicePointcut()",
+            throwing = "exception")
+    public <E extends Throwable> void handleExceptionInsideGrpcService(JoinPoint joinPoint, E exception) {
+        log.error("Runtimeexception caught during gRPC service execution: ", exception);
+        this.exception = exception;
+
+        extractNecessaryInformation();
+        Throwable throwable = invokeMappedMethodSafely();
+        closeStreamObserverOnError(joinPoint.getArgs(), throwable);
+    }
+
+    private void extractNecessaryInformation() {
+
+        final Class<? extends Throwable> exceptionClass = exception.getClass();
+
+        Entry<Object, Method> methodWithInstance =
+                exceptionHandlerMethodResolver.resolveMethodWithInstance(exceptionClass);
+        mappedMethod =
+                Optional.of(methodWithInstance)
+                        .map(Entry::getValue)
+                        .orElseThrow(() -> new IllegalStateException(
+                                "No mapped method found for Exception " + exceptionClass));
+        instanceOfMappedMethod =
+                Optional.of(methodWithInstance)
+                        .map(Entry::getKey)
+                        .orElseThrow(() -> new IllegalStateException(
+                                " No mapped instance found for Exception " + exceptionClass));
+    }
+
+    private Throwable invokeMappedMethodSafely() {
+        try {
+            Object[] instancedParams = determineInstancedParameters(mappedMethod);
+            Object statusThrowable = mappedMethod.invoke(instanceOfMappedMethod, instancedParams);
+            return castToThrowable(statusThrowable);
+        } catch (InvocationTargetException | IllegalAccessException e) {
+            throw new IllegalStateException("No mapped instance found for Exception " + exception);
+        }
+    }
+
+    private Object[] determineInstancedParameters(Method mappedMethod) {
+
+        Parameter[] parameters = mappedMethod.getParameters();
+        Object[] instancedParams = new Object[parameters.length];
+
+        for (int i = 0; i < parameters.length; i++) {
+            Class<?> parameterClass = convertToClass(parameters[i]);
+            if (parameterClass.equals(exception.getClass())) {
+                instancedParams[i] = exception;
+                break;
+            }
+        }
+        return instancedParams;
+    }
+
+    private Class<?> convertToClass(Parameter parameter) {
+        return Optional.of(parameter)
+                .map(Parameter::getParameterizedType)
+                .filter(type -> type instanceof Class)
+                .map(type -> (Class<?>) type)
+                .orElseThrow();
+    }
+
+    private Throwable castToThrowable(Object statusThrowable) {
+        return Optional.of(statusThrowable)
+                .filter(thrbl -> thrbl instanceof Throwable)
+                .map(thrbl -> (Throwable) thrbl)
+                .orElseThrow(() -> new IllegalStateException(
+                        "Return type has to beo f type java.lang.Throable: " + statusThrowable));
+    }
+
+    private void closeStreamObserverOnError(Object[] joinPointParams, Throwable throwable) {
+        for (Object param : joinPointParams) {
+            if (param instanceof StreamObserver) {
+                StreamObserver<?> streamObserver = (StreamObserver<?>) param;
+                streamObserver.onError(throwable);
+            }
+        }
+    }
+
+}
diff --git a/grpc-server-spring-boot-autoconfigure/src/main/java/net/devh/boot/grpc/server/service/exceptionhandling/GrpcExceptionHandler.java b/grpc-server-spring-boot-autoconfigure/src/main/java/net/devh/boot/grpc/server/service/exceptionhandling/GrpcExceptionHandler.java
@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2016-2020 Michael Zhang <yidongnan@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated
+ * documentation files (the "Software"), to deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
+ * WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+package net.devh.boot.grpc.server.service.exceptionhandling;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Documented
+@Target(ElementType.METHOD)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface GrpcExceptionHandler {
+
+    /**
+     * Exceptions handled by the annotated method. If empty, will default to any exceptions listed in the method
+     * argument list.
+     */
+    Class<? extends Throwable>[] value() default {};
+}
diff --git a/grpc-server-spring-boot-autoconfigure/src/main/java/net/devh/boot/grpc/server/service/exceptionhandling/GrpcExceptionHandlerMethodResolver.java b/grpc-server-spring-boot-autoconfigure/src/main/java/net/devh/boot/grpc/server/service/exceptionhandling/GrpcExceptionHandlerMethodResolver.java
diff --git a/grpc-server-spring-boot-autoconfigure/src/main/java/net/devh/boot/grpc/server/service/exceptionhandling/GrpcServiceAdvice.java b/grpc-server-spring-boot-autoconfigure/src/main/java/net/devh/boot/grpc/server/service/exceptionhandling/GrpcServiceAdvice.java

Original file line number	Diff line number	Diff line change
`@@ -108,6 +108,8 @@ public GrpcServiceDiscoverer defaultGrpcServiceDiscoverer() {`
`108`	`108`	`return new AnnotationGrpcServiceDiscoverer();`
`109`	`109`	`}`
`110`	`110`
	`111`	`+ // TODO eventually insert @Conditional`
	`112`	`+`
`111`	`113`	`@ConditionalOnMissingBean`
`112`	`114`	`@Bean`
`113`	`115`	`public HealthStatusManager healthStatusManager() {`