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

Notes for IntelliJ

Building in IntelliJ works best when you import the project as a Gradle project and delegate IDE
build/run actions to Gradle.

You can find this setting at:
Settings -> Build, Execution, Deployment -> Build Tools -> Gradle -> Runner -> Delegate IDE build/run actions to gradle.

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 or later.

For Linux, Mac and MinGW:
$ git clone https://github.com/google/protobuf.git $ cd protobuf $ git checkout v3.5.1 $ ./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. gRPC-java assumes a Release build.

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-3.5.1\src ^ -PvcProtobufLibs=C:\path\to\protobuf-3.5.1\vsprojects\Release ^ -PtargetArch=x86_32

Since specifying those properties every build is bothersome, you can instead
create <project-root>\gradle.properties with contents like:
vcProtobufInclude=C:\\path\\to\\protobuf-3.5.1\\src vcProtobufLibs=C:\\path\\to\\protobuf-3.5.1\\vsprojects\\Release targetArch=x86_32

By default, 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. Since Protobuf is only built for 32-bit by
default, the targetArch=x86_32 is necessary.

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