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Table of contents

• Introduction
• Tasks
• Configuration
• Launch4jLibraryTask
• Launch4jExternalTask
• Kotlin
• Contributors
• Version (see VERSION.md)

Introduction

The gradle-launch4j plugin uses launch4j to create windows .exe files for java applications. This plugin is compatible with the Gradle versions 2 and later.

Tasks

There are 3 tasks:

• createExe - Backward compatible task to generate an .exe file. Execute this task to generate an executable. With default settings this creates the executable under ${project.buildDir}/launch4j and puts all runtime libraries into the lib subfolder.
• createAllExecutables - Helper task to run all tasks of the Launch4jExternalTask and Launch4jLibraryTask type.
• launch4j - Deprecated placeholder task that depends on the above. This task was deprecated in favor of the createExe task and to avoid the name conflict of launch4j on the project.

Launch4j no longer needs to be installed separately, but if you want, you can still use it from the PATH. Since version 2.0 use the Launch4jExternalTask to create your executable.

Configuration

The configuration follows the structure of the launch4j xml file. The gradle-launch4j plugin tries to pick sensible defaults based on the project. The only required value is the mainClassName.

How to include

An example configuration within your build.gradle for use in all Gradle versions might look like:

buildscript {
  repositories {
    jcenter()
  }
  dependencies {
    classpath 'edu.sc.seis.gradle:launch4j:2.4.7'
  }
}

repositories {
  jcenter()
}

apply plugin: 'java'
apply plugin: 'edu.sc.seis.launch4j'

launch4j {
  mainClassName = 'com.example.myapp.Start'
  icon = "${projectDir}/icons/myApp.ico"
}

The same script snippet for new, incubating, plugin mechanism introduced in Gradle 2.1:

plugins {
  id 'java'
  id 'edu.sc.seis.launch4j' version '2.4.7'
}

launch4j {
  mainClassName = 'com.example.myapp.Start'
  icon = "${projectDir}/icons/myApp.ico"
}

If no repository is configured before applying this plugin the Maven central repository will be added to the project.

See the Gradle User guide for more information on how to use a custom plugin and the plugin page for the above settings.

How to configure

The values configurable within the launch4j extension along with their defaults are:

Configurable input configuration

In order to configure the input of the copyL4jLib task set the copyConfigurable property. The following example shows how to use this plugin hand in hand with the shadow plugin:

launch4j {
    outfile = 'TestMain.exe'
    mainClassName = project.mainClassName
    copyConfigurable = []
    jar = "lib/${project.tasks.shadowJar.archiveName}"
}

If you use the outdated fatJar plugin the following configuration correctly wires the execution graph:

fatJar {
    classifier 'fat'
    with jar
    manifest {
        attributes 'Main-Class': project.mainClassName
    }
}

fatJarPrepareFiles.dependsOn jar

launch4j {
    outfile = 'TestMain.exe'
    mainClassName = project.mainClassName
    copyConfigurable = []
    jar = "lib/${project.tasks.fatJar.archiveName}"
}

Launch4jLibraryTask

This task type can be used to build multiple executables with Launch4j. The default launch4j configuration from how to configure is used for the default values but can be adjusted. To avoid replacing the resulting xml file or executable on each invocation, xmlFileName and outfile are set to the task name (name.xml and name.exe respectively).

Creating three executables is as easy as:

launch4j {
    outfile = 'MyApp.exe'
    mainClassName = 'com.example.myapp.Start'
    icon = "${projectDir}/icons/myApp.ico"
    productName = 'My App'
}

task createFastStart(type: edu.sc.seis.launch4j.tasks.Launch4jLibraryTask) {
    outfile = 'FastMyApp.exe'
    mainClassName = 'om.example.myapp.FastStart'
    icon = "${projectDir}/icons/myAppFast.ico"
    fileDescription = 'The lightning fast implementation'
}

task "MyApp-memory"(type: edu.sc.seis.launch4j.tasks.Launch4jLibraryTask) {
    fileDescription = 'The default implementation with increased heap size'
    maxHeapPercent = 50
}

Running the createAllExecutables task will create the following executables in the launch4j folder located in the buildDir:

• MyApp.exe
• FastMyApp.exe
• MyApp-memory.exe

Launch4jExternalTask

The section from above applies to this task, too. This task type has the following additional property:

• String launch4jCmd = "launch4j"

In order to use a launch4j instance named 'launch4j-test' located in the PATH create a task like the following:

launch4j {
    mainClassName = 'com.example.myapp.Start'
}

task createMyApp(type: edu.sc.seis.launch4j.tasks.Launch4jExternalTask) {
    launch4jCmd = 'launch4j-test'
    outfile = 'MyApp.exe'
}

Kotlin

To get started using this plugin from a kotlin build script the above example from the section Launch4jLibraryTask would be written as:

tasks.withType<edu.sc.seis.launch4j.tasks.DefaultLaunch4jTask> {
    outfile = "${appName}.exe"
    mainClassName = mainClass
    icon = "$projectDir/icons/myApp.ico"
    productName = "My App"
}

tasks.register<edu.sc.seis.launch4j.tasks.Launch4jLibraryTask>("createFastStart") {
    outfile = "FastMyApp.exe"
    mainClassName = "com.example.myapp.FastStart"
    icon = "$projectDir/icons/myAppFast.ico"
    fileDescription = "The lightning fast implementation"
}
tasks.register<edu.sc.seis.launch4j.tasks.Launch4jLibraryTask>("MyApp-memory") {
    fileDescription = "The default implementation with increased heap size"
    maxHeapPercent = 50
}

Debugging

To get insight into the launch4j creation process start a launch4j task, e.g. createExe, createExecutables or your custom task, with the script parameter -Pl4j-debug. This will copy the created xml into ${buildDir}/tmp/${task.name}.

In order to debug the created executable call it with the command line argument --l4j-debug. This will create the log file launch4j.log next to the executable.

Using SNAPSHOT versions

When you report a bug and it got fixed, you will have access to some -SNAPSHOT version. Adjust your buildscript to use the OJO repo:

buildscript {
  repositories {
    jcenter()
    maven { url "https://oss.jfrog.org/artifactory/oss-snapshot-local/" }
  }
  dependencies {
    classpath 'edu.sc.seis.gradle:launch4j:latest.integration'
  }
}

apply plugin: 'edu.sc.seis.launch4j'

Contributors

• Sebastian Bögl (Maintainer)
• Philip Crotwell (Creator)
• Sebastian Schuberth
• FourtyTwo

Version

See VERSION.md for more information.