Java Build Examples
Example Builds for Real Projects
Mill comes bundled with example builds for real-world open-source projects, demonstrating how Mill can be used to build code outside of tiny example codebases:
JimFS
package build
import mill._, javalib._, publish._
def sharedCompileIvyDeps = Task {
Agg(
ivy"com.google.auto.service:auto-service:1.0.1",
ivy"com.google.code.findbugs:jsr305:3.0.2",
ivy"org.checkerframework:checker-compat-qual:2.5.5",
ivy"com.ibm.icu:icu4j:73.1"
)
}
object jimfs extends PublishModule with MavenModule {
def publishVersion = "1.3.3.7"
def pomSettings = PomSettings(
description = artifactName(),
organization = "com.google",
url = "https://github.com/google/jimfs",
licenses = Seq(License.MIT),
versionControl = VersionControl.github(owner = "google", repo = "jimfs"),
developers = Nil
)
def ivyDeps = sharedCompileIvyDeps() ++ Agg(
ivy"com.google.guava:guava:31.1-android"
)
def javacOptions = Seq("-processor", "com.google.auto.service.processor.AutoServiceProcessor")
object test extends MavenTests {
def ivyDeps = sharedCompileIvyDeps() ++ Agg(
ivy"junit:junit:4.13.2",
ivy"com.google.guava:guava-testlib:31.1-android",
ivy"com.google.truth:truth:1.1.3",
ivy"com.github.sbt:junit-interface:0.13.2",
ivy"com.ibm.icu:icu4j:73.1"
)
def testFramework = "com.novocode.junit.JUnitFramework"
}
}JimFS is a small Java library implementing an in-memory filesystem. It is commonly used in test suites to validate filesystem operations without needing to write to disk.
It has a relatively simple codebase structure, a single module and test suite.
It has a number of compile-time-only dependencies shared between the library and
test suite. One wrinkle is that it uses annotation processors as part of its build,
which Mill supports by providing the relevant ivyDeps of the annotation processor
and providing javacOptions to invoke it.
Project home: https://github.com/google/jimfs
> ./mill jimfs.test
Test run com.google.common.jimfs.FileTest started
Test run com.google.common.jimfs.FileTest finished: 0 failed, 0 ignored, 7 total...
...Apache Commons IO
package build
import mill._, javalib._, publish._
import mill.define.ModuleRef
import $ivy.`com.lihaoyi::mill-contrib-jmh:$MILL_VERSION`
import contrib.jmh.JmhModule
object `package` extends RootModule with PublishModule with MavenModule {
object ZincWorkerJava11 extends ZincWorkerModule {
def jvmId = "temurin:11.0.24"
}
override def zincWorker = ModuleRef(ZincWorkerJava11)
def javacOptions = Seq("-encoding", "UTF-8")
def publishVersion = "2.17.0-SNAPSHOT"
def pomSettings = PomSettings(
description = artifactName(),
organization = "org.apache.commons",
url = "https://github.com/apache/commons-io",
licenses = Seq(License.`Apache-2.0`),
versionControl = VersionControl.github(owner = "apache", repo = "commons-io"),
developers = Nil
)
object test extends MavenTests with TestModule.Junit5 with JmhModule {
def testSandboxWorkingDir = false
def jmhCoreVersion = "1.37"
def ivyDeps = super.ivyDeps() ++ Agg(
ivy"org.junit.jupiter:junit-jupiter:5.10.3",
ivy"org.junit-pioneer:junit-pioneer:1.9.1",
ivy"net.bytebuddy:byte-buddy:1.14.18",
ivy"net.bytebuddy:byte-buddy-agent:1.14.18",
ivy"org.mockito:mockito-inline:4.11.0",
ivy"com.google.jimfs:jimfs:1.3.0",
ivy"org.apache.commons:commons-lang3:3.14.0",
ivy"commons-codec:commons-codec:1.17.1",
ivy"org.openjdk.jmh:jmh-core:1.37",
ivy"org.openjdk.jmh:jmh-generator-annprocess:1.37"
)
}
}The Apache Commons IO library contains utility classes, stream implementations, file filters, file comparators, endian transformation classes, and much more.
The core library commonsio is dependency-free, but the test suite commonsio.test
as a number of libraries included. It also ships with JMH benchmarks, which Mill
supports via the built in JMH plugin
Project home: https://github.com/apache/commons-io
> ./mill compile
compiling 254 Java sources...
...
> ./mill test.compile
compiling 261 Java sources...
...
> ./mill test.testOnly org.apache.commons.io.FileUtilsTest
Test org.apache.commons.io.FileUtilsTest#testCopyFile1() started
Test org.apache.commons.io.FileUtilsTest#testCopyFile1() finished, took ...
...
> ./mill test.testOnly org.apache.commons.io.FileSystemTest
Test org.apache.commons.io.FileSystemTest#testIsLegalName() started
Test org.apache.commons.io.FileSystemTest#testIsLegalName() finished, took ...
...
> ./mill test.runJmh '.*PathUtilsContentEqualsBenchmark' -bm SingleShotTime
Benchmark Mode Cnt ...
PathUtilsContentEqualsBenchmark.testCurrent_fileContentEquals ss 5 ...
PathUtilsContentEqualsBenchmark.testCurrent_fileContentEquals_Blackhole ss 5 ...
PathUtilsContentEqualsBenchmark.testProposal_contentEquals ss 5 ...
PathUtilsContentEqualsBenchmark.testProposal_contentEquals_Blackhole ss 5 ...Real World Mill Builds
C3P0
C3P0 is a JDBC connection pooling library written in Java, built using the Mill build tool.