grpc-java/examples

grpc Examples

The examples require grpc-java to already be built. You are strongly encouraged to check out a git release tag, since there will already be a build of grpc available. Otherwise you must follow COMPILING.

You may want to read through the Quick Start Guide before trying out the examples.

Basic examples

• Hello world

• Route guide

• Metadata

• Error handling

• Compression

• Flow control

• Json serialization

• Authentication

• Google Authentication

To build the examples

1. Install gRPC Java library SNAPSHOT locally, including code generation plugin (Only need this step for non-released versions, e.g. master HEAD).

2. Run in this directory:

$ ./gradlew installDist

This creates the scripts hello-world-server, hello-world-client, route-guide-server, route-guide-client, etc. in the build/install/examples/bin/ directory that run the examples. Each example requires the server to be running before starting the client.

For example, to try the hello world example first run:

$ ./build/install/examples/bin/hello-world-server

And in a different terminal window run:

$ ./build/install/examples/bin/hello-world-client

That's it!

Please refer to gRPC Java's README and tutorial for more information.

Maven

If you prefer to use Maven:

1. Install gRPC Java library SNAPSHOT locally, including code generation plugin (Only need this step for non-released versions, e.g. master HEAD).

2. Run in this directory:

$ mvn verify
$ # Run the server
$ mvn exec:java -Dexec.mainClass=io.grpc.examples.helloworld.HelloWorldServer
$ # In another terminal run the client
$ mvn exec:java -Dexec.mainClass=io.grpc.examples.helloworld.HelloWorldClient

Bazel

If you prefer to use Bazel:

$ bazel build :hello-world-server :hello-world-client
$ # Run the server
$ bazel-bin/hello-world-server
$ # In another terminal run the client
$ bazel-bin/hello-world-client

Other examples

• Android examples

• Secure channel examples

  • TLS examples

  • ALTS examples

• Kotlin examples

• Kotlin Android examples

Unit test examples

Examples for unit testing gRPC clients and servers are located in examples/src/test.

In general, we DO NOT allow overriding the client stub. We encourage users to leverage InProcessTransport as demonstrated in the examples to write unit tests. InProcessTransport is light-weight and runs the server and client in the same process without any socket/TCP connection.

For testing a gRPC client, create the client with a real stub using an InProcessChannel, and test it against an InProcessServer with a mock/fake service implementation.

For testing a gRPC server, create the server as an InProcessServer, and test it against a real client stub with an InProcessChannel.

The gRPC-java library also provides a JUnit rule, GrpcCleanupRule, to do the graceful shutdown boilerplate for you.

Even more examples

A wide variety of third-party examples can be found here.