Building gRPC-Java

Building is only necessary if you are making changes to gRPC-Java.

Building requires JDK 8, as our tests use TLS.

grpc-java has a C++ code generation plugin for protoc. Since many Java developers don't have C compilers installed and don't need to modify the codegen, the build can skip it. To skip, create the file <project-root>/gradle.properties and add skipCodegen=true.

Then, to build, run:

$ ./gradlew build

To install the artifacts to your Maven local repository for use in your own project, run:

$ ./gradlew install

How to Build Code Generation Plugin

This section is only necessary if you are making changes to the code generation. Most users only need to use skipCodegen=true as discussed above.

Build Protobuf

The codegen plugin is C++ code and requires protobuf 3.0.0-beta-1.

For Linux, Mac and MinGW:

$ git clone https://github.com/google/protobuf.git
$ cd protobuf
$ git checkout v3.0.0-beta-1
$ ./autogen.sh
$ ./configure
$ make
$ make check
$ sudo make install

If you are comfortable with C++ compilation and autotools, you can specify a --prefix for Protobuf and use -I in CXXFLAGS, -L in LDFLAGS, LD_LIBRARY_PATH, and PATH to reference it. The environment variables will be used when building grpc-java.

Protobuf installs to /usr/local by default.

For Visual C++, please refer to the Protobuf README for how to compile Protobuf.

Linux and MinGW

If /usr/local/lib is not in your library search path, you can add it by running:

$ sudo sh -c 'echo /usr/local/lib >> /etc/ld.so.conf'
$ sudo ldconfig

Mac

Some versions of Mac OS X (e.g., 10.10) doesn't have /usr/local in the default search paths for header files and libraries. It will fail the build of the codegen. To work around this, you will need to set environment variables:

$ export CXXFLAGS="-I/usr/local/include" LDFLAGS="-L/usr/local/lib"

Notes for Visual C++

When building on Windows and VC++, you need to specify project properties for Gradle to find protobuf:

.\gradlew install ^
    -PvcProtobufInclude=C:\path\to\protobuf-3.0.0-beta-1\src ^
    -PvcProtobufLibs=C:\path\to\protobuf-3.0.0-beta-1\vsprojects\Release

Since specifying those properties every build is bothersome, you can instead create <project-root>\gradle.properties with contents like:

vcProtobufInclude=C:\\path\\to\\protobuf-3.0.0-beta-1\\src
vcProtobufLibs=C:\\path\\to\\protobuf-3.0.0-beta-1\\vsprojects\\Release

The build script will build the codegen for the same architecture as the Java runtime installed on your system. If you are using 64-bit JVM, the codegen will be compiled for 64-bit, that means you must have compiled Protobuf in 64-bit.

Notes for MinGW on Windows

If you have both MinGW and VC++ installed on Windows, VC++ will be used by default. To override this default and use MinGW, add -PvcDisable=true to your Gradle command line or add vcDisable=true to your <project-root>\gradle.properties.

Notes for Unsupported Operating Systems

The build script pulls pre-compiled protoc from Maven Central by default. We have built protoc binaries for popular systems, but they may not work for your system. If protoc cannot be downloaded or would not run, you can use the one that has been built by your own, by adding this property to <project-root>/gradle.properties:

protoc=/path/to/protoc