This repo provides Java rules for the please build system.

See ./example in this repo for a working example.

# BUILD
# This adds the plugin to your project
github_repo(
    name = "java_rules",
    repo = "please-build/java-rules",
    revision = "<Some git tag, commit, or other reference>",
)

# src/main/java/build/please/foo/BUILD
# This defines a java library that can be depended on by other Java rules
java_library(
    name = "foo",
    srcs = ["Foo.java"],
    visibility = ["//src/test/java/build/please/..."]
)

# src/test/java/build/please/foo/BUILD
# A test for the above library. 
java_test(
    name = "foo_test",
    srcs = ["FooTest.java"],
    deps = [
        "//third_party/java:junit", 
        "//src/main/java/build/please/foo",
    ]
)

# src/main/java/build/please/foo/BUILD
# This produces a self-executing .jar 
java_binary(
    name = "app",
    main_class = "build.please.Main",
    srcs = ["Main.java"],
    deps = ["//src/main/java/build/please/foo"]
)

# third_party/java/BUILD
# These rules pull down third party dependencies from maven. 
maven_jar(
    name = "junit",
    hash = "59721f0805e223d84b90677887d9ff567dc534d7c502ca903c0c2b17f05c116a",
    id = "junit:junit:4.12",
    deps = [
        ":hamcrest",
    ],
)

maven_jar(
    name = "hamcrest",
    hash = "4877670629ab96f34f5f90ab283125fcd9acb7e683e66319a68be6eb2cca60de",
    id = "org.hamcrest:hamcrest-all:1.3",
)

Then add this to your .plzconfig:

[Parse]
PreloadSubincludes = @java_rules//build_defs:java

Alternatively, if you're not using Java everywhere, you may add subinclude("@java_rules//build_defs:java") to each BUILD individually.

By default, Please will use the JDK on the path. Optionally, you may use java_toolchain() to manage your JDK:

# third_party/java/BUILD
java_toolchain(
    name = "toolchain",
    jdk_url = "https://corretto.aws/downloads/resources/11.0.8.10.1/amazon-corretto-11.0.8.10.1-linux-x64.tar.gz",
)

This can then be configured to be used by adding the following config:

[Plugin "Java"]
Toolchain = //third_party/java:toolchain

Plugins are configured through the Plugin section like so:

[Plugin "java"]
SomeConfig = some value

The available configuration options for this plugin are documented here.

The path to the Java compiler to use. Defaults to javac.

[Plugin "java"]
JavacTool = /opt/java/bin/javac

Any additional flags to apply to the javac tool.

[Plugin "java"]
JavacFalgs = --flag1 --flag2

Any additional flags to apply to the javac tool when compiling tests.

[Plugin "java"]
TestJavacFlags = --flag1 --flag2

The tool used to run Java tests. Defaults to the junit runner for this plugin version i.e. @java_rules//tools:junit_runner

[Plugin "java"]
JunitRunner = /opts/please/bin/junit_runner

or

[Plugin "java"]
JunitRunner = //tools:my_custom_junit_runner

The source level of the project. Defaults to 8.

[Plugin "java"]
SourceLevel = 15

The target level of the project. Defaults to 8.

[Plugin "java"]
TargetLevel = 15

The release level of the project. Defaults to 8.

[Plugin "java"]
ReleaseLevel = 15

If set, Please will use this javac worker rather than javac directly. This can speed up compile times as the javac process can be reused between build actions.

To start using the javac worker, add this config to your repo, where java_rules is the name of the plugin's github_repo() rule:

[Plugin "java"]
JavacWorker = @java_rules//tools:javac_worker

If set, please will use the jdk provided by the java_toolchain() rule specified by this build label. See the toolchain section above for more info.

[Plugin "java"]
Toolchain = //third_party/java:toolchain

The test package to use when none is specifically set on the java_test() rule. If not set, Please will run all tests present in the .jar that are not from third party code.

[Plugin "java"]
DefaultTestPackage = please.build.

The maven repositories to load jars from. This value can be repeated and defaults to https://repo1.maven.org/maven2 and https://repo.maven.apache.org/maven2, the canonical Maven Central repository URLs.

To add a custom repo, you may do so by setting the following:

[Plugin "java"]
MavenRepo = https://repo1.maven.org/maven2
MavenRepo = https://repo.maven.apache.org/maven2
MavenRepo = https://maven.repo.org