diff --git a/contrib/grpc-contrib/src/main/java/com/salesforce/grpc/contrib/interceptor/TransmitUnexpectedExceptionInterceptor.java b/contrib/grpc-contrib/src/main/java/com/salesforce/grpc/contrib/interceptor/TransmitUnexpectedExceptionInterceptor.java
new file mode 100644
index 00000000..26cc9575
--- /dev/null
+++ b/contrib/grpc-contrib/src/main/java/com/salesforce/grpc/contrib/interceptor/TransmitUnexpectedExceptionInterceptor.java
@@ -0,0 +1,151 @@
+/*
+ * Copyright (c) 2019, Salesforce.com, Inc.
+ * All rights reserved.
+ * Licensed under the BSD 3-Clause license.
+ * For full license text, see LICENSE.txt file in the repo root or https://opensource.org/licenses/BSD-3-Clause
+ */
+
+package com.salesforce.grpc.contrib.interceptor;
+
+import io.grpc.*;
+
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * A class that intercepts uncaught exceptions of all types and handles them by closing the {@link ServerCall}, and
+ * transmitting the exception's description and stack trace to the client. This class is a complement to gRPC's
+ * {@code TransmitStatusRuntimeExceptionInterceptor}.
+ *
+ * Without this interceptor, gRPC will strip all details and close the {@link ServerCall} with
+ * a generic {@link Status#UNKNOWN} code.
+ *
+ *
Security warning: the exception description and stack trace may contain sensitive server-side
+ * state information, and generally should not be sent to clients. Only install this interceptor
+ * if all clients are trusted.
+ */
+// Heavily inspired by https://github.com/saturnism/grpc-java-by-example/blob/master/error-handling-example/error-server/src/main/java/com/example/grpc/server/UnknownStatusDescriptionInterceptor.java
+public class TransmitUnexpectedExceptionInterceptor implements ServerInterceptor {
+
+ private final Set> exactTypes = new HashSet<>();
+ private final Set> parentTypes = new HashSet<>();
+
+ /**
+ * Allows this interceptor to match on an exact exception type.
+ * @param exactType The exact type to match on.
+ * @return this
+ */
+ public TransmitUnexpectedExceptionInterceptor forExactType(Class exactType) {
+ this.exactTypes.add(exactType);
+ return this;
+ }
+
+ /**
+ * Allows this interceptor to match on a set of exact exception type.
+ * @param exactTypes The set of exact types to match on.
+ * @return this
+ */
+ public TransmitUnexpectedExceptionInterceptor forExactTypes(Collection> exactTypes) {
+ this.exactTypes.addAll(exactTypes);
+ return this;
+ }
+
+ /**
+ * Allows this interceptor to match on any exception type deriving from {@code parentType}.
+ * @param parentType The parent type to match on.
+ * @return this
+ */
+ public TransmitUnexpectedExceptionInterceptor forParentType(Class parentType) {
+ this.parentTypes.add(parentType);
+ return this;
+ }
+
+ /**
+ * Allows this interceptor to match on any exception type deriving from any element of {@code parentTypes}.
+ * @param parentTypes The set of parent types to match on.
+ * @return this
+ */
+ public TransmitUnexpectedExceptionInterceptor forParentTypes(Collection> parentTypes) {
+ this.parentTypes.addAll(parentTypes);
+ return this;
+ }
+
+ /**
+ * Allows this interceptor to match all exceptions. Use with caution!
+ * @return this
+ */
+ public TransmitUnexpectedExceptionInterceptor forAllExceptions() {
+ return forParentType(Throwable.class);
+ }
+
+ @Override
+ public ServerCall.Listener interceptCall(ServerCall call, Metadata headers, ServerCallHandler next) {
+ ServerCall wrappedCall = new ForwardingServerCall.SimpleForwardingServerCall(call) {
+ @Override
+ public void sendMessage(RespT message) {
+ super.sendMessage(message);
+ }
+
+ @Override
+ public void close(Status status, Metadata trailers) {
+
+ if (status.getCode() == Status.Code.UNKNOWN &&
+ status.getDescription() == null &&
+ status.getCause() != null &&
+ exceptionTypeIsAllowed(status.getCause().getClass())) {
+ Throwable e = status.getCause();
+ status = Status.INTERNAL
+ .withDescription(e.getMessage())
+ .augmentDescription(stacktraceToString(e));
+ }
+ super.close(status, trailers);
+ }
+ };
+
+ return new ForwardingServerCallListener.SimpleForwardingServerCallListener(next.startCall(wrappedCall, headers)) {
+ @Override
+ public void onHalfClose() {
+ try {
+ super.onHalfClose();
+ } catch (Throwable e) {
+ if (exceptionTypeIsAllowed(e.getClass())) {
+ call.close(Status.INTERNAL
+ .withDescription(e.getMessage())
+ .augmentDescription(stacktraceToString(e)), new Metadata());
+ } else {
+ throw e;
+ }
+ }
+ }
+ };
+ }
+
+ private boolean exceptionTypeIsAllowed(Class exceptionClass) {
+ // exact matches
+ for (Class clazz : exactTypes) {
+ if (clazz.equals(exceptionClass)) {
+ return true;
+ }
+ }
+
+ // parent type matches
+ for (Class clazz : parentTypes) {
+ if (clazz.isAssignableFrom(exceptionClass)) {
+ return true;
+ }
+ }
+
+ // no match
+ return false;
+ }
+
+ private String stacktraceToString(Throwable e) {
+ StringWriter stringWriter = new StringWriter();
+ PrintWriter printWriter = new PrintWriter(stringWriter);
+ e.printStackTrace(printWriter);
+ return stringWriter.toString();
+ }
+}
\ No newline at end of file
diff --git a/contrib/grpc-contrib/src/test/java/com/salesforce/grpc/contrib/interceptor/TransmitUnexpectedExceptionInterceptorTest.java b/contrib/grpc-contrib/src/test/java/com/salesforce/grpc/contrib/interceptor/TransmitUnexpectedExceptionInterceptorTest.java
new file mode 100644
index 00000000..9cdcde4c
--- /dev/null
+++ b/contrib/grpc-contrib/src/test/java/com/salesforce/grpc/contrib/interceptor/TransmitUnexpectedExceptionInterceptorTest.java
@@ -0,0 +1,212 @@
+/*
+ * Copyright (c) 2019, Salesforce.com, Inc.
+ * All rights reserved.
+ * Licensed under the BSD 3-Clause license.
+ * For full license text, see LICENSE.txt file in the repo root or https://opensource.org/licenses/BSD-3-Clause
+ */
+
+package com.salesforce.grpc.contrib.interceptor;
+
+import com.salesforce.grpc.contrib.GreeterGrpc;
+import com.salesforce.grpc.contrib.HelloRequest;
+import com.salesforce.grpc.contrib.HelloResponse;
+import io.grpc.ServerInterceptor;
+import io.grpc.ServerInterceptors;
+import io.grpc.Status;
+import io.grpc.StatusRuntimeException;
+import io.grpc.stub.StreamObserver;
+import io.grpc.testing.GrpcServerRule;
+import org.junit.Rule;
+import org.junit.Test;
+
+import java.util.Iterator;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+public class TransmitUnexpectedExceptionInterceptorTest {
+ @Rule
+ public final GrpcServerRule serverRule = new GrpcServerRule();
+
+ @Test
+ public void noExceptionDoesNotInterfere() {
+ GreeterGrpc.GreeterImplBase svc = new GreeterGrpc.GreeterImplBase() {
+ @Override
+ public void sayHello(HelloRequest request, StreamObserver responseObserver) {
+ responseObserver.onNext(HelloResponse.newBuilder().setMessage("Hello " + request.getName()).build());
+ responseObserver.onCompleted();
+ }
+ };
+
+ ServerInterceptor interceptor = new TransmitUnexpectedExceptionInterceptor();
+
+ serverRule.getServiceRegistry().addService(ServerInterceptors.intercept(svc, interceptor));
+ GreeterGrpc.GreeterBlockingStub stub = GreeterGrpc.newBlockingStub(serverRule.getChannel());
+
+ stub.sayHello(HelloRequest.newBuilder().setName("World").build());
+ }
+
+ @Test
+ public void exactTypeMatches() {
+ GreeterGrpc.GreeterImplBase svc = new GreeterGrpc.GreeterImplBase() {
+ @Override
+ public void sayHello(HelloRequest request, StreamObserver responseObserver) {
+ responseObserver.onError(new ArithmeticException("Divide by zero"));
+ }
+ };
+
+ ServerInterceptor interceptor = new TransmitUnexpectedExceptionInterceptor().forExactType(ArithmeticException.class);
+
+ serverRule.getServiceRegistry().addService(ServerInterceptors.intercept(svc, interceptor));
+ GreeterGrpc.GreeterBlockingStub stub = GreeterGrpc.newBlockingStub(serverRule.getChannel());
+
+ assertThatThrownBy(() -> stub.sayHello(HelloRequest.newBuilder().setName("World").build()))
+ .isInstanceOf(StatusRuntimeException.class)
+ .matches(sre -> ((StatusRuntimeException) sre).getStatus().getCode().equals(Status.INTERNAL.getCode()), "is Status.INTERNAL")
+ .hasMessageContaining("Divide by zero");
+ }
+
+ @Test
+ public void parentTypeMatches() {
+ GreeterGrpc.GreeterImplBase svc = new GreeterGrpc.GreeterImplBase() {
+ @Override
+ public void sayHello(HelloRequest request, StreamObserver responseObserver) {
+ responseObserver.onError(new ArithmeticException("Divide by zero"));
+ }
+ };
+
+ ServerInterceptor interceptor = new TransmitUnexpectedExceptionInterceptor().forParentType(RuntimeException.class);
+
+ serverRule.getServiceRegistry().addService(ServerInterceptors.intercept(svc, interceptor));
+ GreeterGrpc.GreeterBlockingStub stub = GreeterGrpc.newBlockingStub(serverRule.getChannel());
+
+ assertThatThrownBy(() -> stub.sayHello(HelloRequest.newBuilder().setName("World").build()))
+ .isInstanceOf(StatusRuntimeException.class)
+ .matches(sre -> ((StatusRuntimeException) sre).getStatus().getCode().equals(Status.INTERNAL.getCode()), "is Status.INTERNAL")
+ .hasMessageContaining("Divide by zero");
+ }
+
+ @Test
+ public void parentTypeMatchesExactly() {
+ GreeterGrpc.GreeterImplBase svc = new GreeterGrpc.GreeterImplBase() {
+ @Override
+ public void sayHello(HelloRequest request, StreamObserver responseObserver) {
+ responseObserver.onError(new RuntimeException("Divide by zero"));
+ }
+ };
+
+ ServerInterceptor interceptor = new TransmitUnexpectedExceptionInterceptor().forParentType(RuntimeException.class);
+
+ serverRule.getServiceRegistry().addService(ServerInterceptors.intercept(svc, interceptor));
+ GreeterGrpc.GreeterBlockingStub stub = GreeterGrpc.newBlockingStub(serverRule.getChannel());
+
+ assertThatThrownBy(() -> stub.sayHello(HelloRequest.newBuilder().setName("World").build()))
+ .isInstanceOf(StatusRuntimeException.class)
+ .matches(sre -> ((StatusRuntimeException) sre).getStatus().getCode().equals(Status.INTERNAL.getCode()), "is Status.INTERNAL")
+ .hasMessageContaining("Divide by zero");
+ }
+
+ @Test
+ public void alleMatches() {
+ GreeterGrpc.GreeterImplBase svc = new GreeterGrpc.GreeterImplBase() {
+ @Override
+ public void sayHello(HelloRequest request, StreamObserver responseObserver) {
+ responseObserver.onError(new ArithmeticException("Divide by zero"));
+ }
+ };
+
+ ServerInterceptor interceptor = new TransmitUnexpectedExceptionInterceptor().forAllExceptions();
+
+ serverRule.getServiceRegistry().addService(ServerInterceptors.intercept(svc, interceptor));
+ GreeterGrpc.GreeterBlockingStub stub = GreeterGrpc.newBlockingStub(serverRule.getChannel());
+
+ assertThatThrownBy(() -> stub.sayHello(HelloRequest.newBuilder().setName("World").build()))
+ .isInstanceOf(StatusRuntimeException.class)
+ .matches(sre -> ((StatusRuntimeException) sre).getStatus().getCode().equals(Status.INTERNAL.getCode()), "is Status.INTERNAL")
+ .hasMessageContaining("Divide by zero");
+ }
+
+ @Test
+ public void unknownTypeDoesNotMatch() {
+ GreeterGrpc.GreeterImplBase svc = new GreeterGrpc.GreeterImplBase() {
+ @Override
+ public void sayHello(HelloRequest request, StreamObserver responseObserver) {
+ responseObserver.onError(new NullPointerException("Bananas!"));
+ }
+ };
+
+ ServerInterceptor interceptor = new TransmitUnexpectedExceptionInterceptor().forExactType(ArithmeticException.class);
+
+ serverRule.getServiceRegistry().addService(ServerInterceptors.intercept(svc, interceptor));
+ GreeterGrpc.GreeterBlockingStub stub = GreeterGrpc.newBlockingStub(serverRule.getChannel());
+
+ assertThatThrownBy(() -> stub.sayHello(HelloRequest.newBuilder().setName("World").build()))
+ .isInstanceOf(StatusRuntimeException.class)
+ .matches(sre -> ((StatusRuntimeException) sre).getStatus().getCode().equals(Status.UNKNOWN.getCode()), "is Status.UNKNOWN")
+ .hasMessageContaining("UNKNOWN");
+ }
+
+ @Test
+ public void unexpectedExceptionCanMatch() {
+ GreeterGrpc.GreeterImplBase svc = new GreeterGrpc.GreeterImplBase() {
+ @Override
+ public void sayHello(HelloRequest request, StreamObserver responseObserver) {
+ throw new ArithmeticException("Divide by zero");
+ }
+ };
+
+ ServerInterceptor interceptor = new TransmitUnexpectedExceptionInterceptor().forExactType(ArithmeticException.class);
+
+ serverRule.getServiceRegistry().addService(ServerInterceptors.intercept(svc, interceptor));
+ GreeterGrpc.GreeterBlockingStub stub = GreeterGrpc.newBlockingStub(serverRule.getChannel());
+
+ assertThatThrownBy(() -> stub.sayHello(HelloRequest.newBuilder().setName("World").build()))
+ .isInstanceOf(StatusRuntimeException.class)
+ .matches(sre -> ((StatusRuntimeException) sre).getStatus().getCode().equals(Status.INTERNAL.getCode()), "is Status.INTERNAL")
+ .hasMessageContaining("Divide by zero");
+ }
+
+ @Test
+ public void unexpectedExceptionCanNotMatch() {
+ GreeterGrpc.GreeterImplBase svc = new GreeterGrpc.GreeterImplBase() {
+ @Override
+ public void sayHello(HelloRequest request, StreamObserver responseObserver) {
+ throw new ArithmeticException("Divide by zero");
+ }
+ };
+
+ ServerInterceptor interceptor = new TransmitUnexpectedExceptionInterceptor().forExactType(NullPointerException.class);
+
+ serverRule.getServiceRegistry().addService(ServerInterceptors.intercept(svc, interceptor));
+ GreeterGrpc.GreeterBlockingStub stub = GreeterGrpc.newBlockingStub(serverRule.getChannel());
+
+ assertThatThrownBy(() -> stub.sayHello(HelloRequest.newBuilder().setName("World").build()))
+ .isInstanceOf(StatusRuntimeException.class)
+ .matches(sre -> ((StatusRuntimeException) sre).getStatus().getCode().equals(Status.UNKNOWN.getCode()), "is Status.UNKNOWN")
+ .hasMessageContaining("UNKNOWN");
+ }
+
+ @Test
+ public void unexpectedExceptionCanMatchStreaming() {
+ GreeterGrpc.GreeterImplBase svc = new GreeterGrpc.GreeterImplBase() {
+ @Override
+ public void sayHelloStream(HelloRequest request, StreamObserver responseObserver) {
+ responseObserver.onNext(HelloResponse.getDefaultInstance());
+ responseObserver.onNext(HelloResponse.getDefaultInstance());
+ throw new ArithmeticException("Divide by zero");
+ }
+ };
+
+ ServerInterceptor interceptor = new TransmitUnexpectedExceptionInterceptor().forExactType(ArithmeticException.class);
+
+ serverRule.getServiceRegistry().addService(ServerInterceptors.intercept(svc, interceptor));
+ GreeterGrpc.GreeterBlockingStub stub = GreeterGrpc.newBlockingStub(serverRule.getChannel());
+
+ Iterator it = stub.sayHelloStream(HelloRequest.newBuilder().setName("World").build());
+ it.next();
+ it.next();
+ assertThatThrownBy(it::next)
+ .isInstanceOf(StatusRuntimeException.class)
+ .matches(sre -> ((StatusRuntimeException) sre).getStatus().getCode().equals(Status.INTERNAL.getCode()), "is Status.INTERNAL")
+ .hasMessageContaining("Divide by zero");
+ }
+}
diff --git a/contrib/grpc-contrib/src/test/proto/helloworld.proto b/contrib/grpc-contrib/src/test/proto/helloworld.proto
index d1abddce..a68cb492 100644
--- a/contrib/grpc-contrib/src/test/proto/helloworld.proto
+++ b/contrib/grpc-contrib/src/test/proto/helloworld.proto
@@ -14,6 +14,9 @@ service Greeter {
// Sends a greeting
rpc SayHello (HelloRequest) returns (HelloResponse) {}
+ // Sends many greetings
+ rpc SayHelloStream (HelloRequest) returns (stream HelloResponse) {}
+
// Sends the current time
rpc SayTime (google.protobuf.Empty) returns (TimeResponse) {}
}