Link

Since Apache Ant 1.10.6

Description

Assembles jmod files into an executable image. Equivalent to the JDK's jlink tool.

Requires Java 9 or later.

Parameters

Parameters specified as nested elements

<link> can have the following nested elements:

• modulepath
• module
• observableModule
• launcher
• locale
• resourceOrder
• excludeResources
• excludeFiles
• compress
• releaseInfo

modulepath

Path-like structure pointing to jmod files to link into image.

module

Names a single module to be placed in the linked image. This may be specified multiple times.

Attributes:

observableModule

Names a module visible to the linking process, instead of every module in the module path being considered. This may be specified multiple times.

Attributes:

launcher

Specifies an executable file which will be added to the linked image, which executes a particular module's main class. Attributes:

locale

Specifies locales to include in linked image. May be specified multiple times. Requires jdk.localedata module. Attributes:

resourceOrder

Explicit resource search order in linked image. May be specified multiple times. Attributes:

If the resourceOrder attribute is also present on the task, its patterns are treated as if they occur before patterns in nested <resourceOrder> elements.

excludeResources

Excludes files from linked image tree. May be specified multiple times. Attributes:

excludeFiles

Excludes files from linked image. May be specified multiple times. Attributes:

compress

Describes how image should be compressed. Attributes:

<compress> can also have any number of nested <files> elements, with these attributes:

releaseInfo

Replaces, augments, or trims the image's release info properties. Can be specified multiple times. Attributes:

<releaseInfo> can also have any number of these nested elements:

add

Specifies additional release info properties. Attributes:

delete

Property keys to remove from applicaiton's release info. Attributes:

Examples

Basic linking

<jmod destfile="MyApp.jmod" classpath="build/myapp.jar"/>
<link destDir="build/image" modulepath="MyApp.jmod"
      modules="com.example.myapp"/>

Custom binaries

This will cause a bin/MyEditor script to appear in the image:

<jmod destfile="MyApp.jmod" classpath="build/myapp.jar"/>
<link destDir="build/image" modulepath="MyApp.jmod"
      modules="com.example.myapp"
      launchers="MyEditor=com.example.myapp/com.example.myapp.editors.EditorMain"/>

Same thing, using a nested launcher element:

<jmod destfile="MyApp.jmod" classpath="build/myapp.jar"/>
<link destDir="build/image" modulepath="MyApp.jmod"
      modules="com.example.myapp">

    <launcher name="MyEditor" module="com.example.myapp"
              mainClass="com.example.myapp.editors.EditorMain"/>

</link>

Limiting locales

Include just the locales needed by the application from the jdk.localedata module:

<jmod destfile="MyApp.jmod" classpath="build/myapp.jar"/>
<link destDir="build/image" modulepath="MyApp.jmod"
      modules="com.example.myapp,jdk.localedata"
      locales="zh,jp-*"/>

Compressed image

Compress entire image:

<jmod destfile="MyApp.jmod" classpath="build/myapp.jar"/>
<link destDir="build/image" modulepath="MyApp.jmod"
      modules="com.example.myapp,jdk.localedata"
      compress="zip"/>

Compress only some files in the image:

<jmod destfile="MyApp.jmod" classpath="build/myapp.jar"/>
<link destDir="build/image" modulepath="MyApp.jmod"
      modules="com.example.myapp,jdk.localedata">

    <compress level="zip" files=".*\.xml"/>

</link>

Cross-compiling

To create an image for a different platform:

• Download the JDK for that platform, and expand the archive manually into a directory of your choice. (Downloading a zip or tar.gz version of a JDK instead of an installer will make this easier.)
• Determine the foreign JDK's platform string. This can be done with a command that examines the JDK's jmods/java.base.jmod file:

  jmod describe "$FOREIGN_JDK_HOME"/jmods/java.base.jmod | grep '^platform'
  

• Create your jmod using the foreign JDK's platform string:

  <jmod destfile="MyApp.jmod" classpath="build/myapp.jar" platform="windows-amd64"/>
  

• Link with the foreign JDK's jmods directory in the module path:

  <link destDir="build/image"
        modulepath="MyApp.jmod;${foreign-jdk-home}/jmods"
        modules="com.example.myapp"/>