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javamavenjpackage

ClassNotFoundException when launching an installed executable created with jpackage

My process for generating the MSI installer is as follows.

  1. Run mvn install to generate Example-1.0-SNAPSHOT-jar-with-dependencies.jar.
  2. Run windows-executable.bat to generate Example-1.0.0.msi.
  3. Install Example-1.0.0.msi.
  4. Go to the install directory, open a terminal, and run Example-1.0.0.exe to see any errors preventing the application from launching.

This POM file (irrelevant sections removed) is used during mvn install to generate Example-1.0-SNAPSHOT-jar-with-dependencies.jar.

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.github.Valkryst</groupId>
    <artifactId>Example</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>11</maven.compiler.source>
        <maven.compiler.target>11</maven.compiler.target>
        <maven.compiler.release>11</maven.compiler.release>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    </properties>

    <repositories>
        <!-- REMOVED -->
    </repositories>

    <dependencies>
        <!-- REMOVED -->
    </dependencies>

    <build>
        <sourceDirectory>src</sourceDirectory>
        <resources>
            <resource>
                <directory>res</directory>
            </resource>
        </resources>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <compilerArgs>
                        <arg>--add-exports=java.desktop/sun.java2d.d3d=ALL-UNNAMED</arg>
                        <arg>--add-exports=java.desktop/sun.java2d.pipe.hw=ALL-UNNAMED</arg>
                        <arg>--add-exports=java.desktop/java.awt.peer=ALL-UNNAMED</arg>
                        <arg>--add-exports=java.desktop/sun.java2d=ALL-UNNAMED</arg>
                    </compilerArgs>
                    <fork>true</fork>
                </configuration>
            </plugin>

            <!-- Used, during the test phase of the build, to run the unit tests -->
            <plugin>
                <groupId>org.apache.maven.surefire</groupId>
                <artifactId>surefire</artifactId>
                <version>2.21.0</version>
            </plugin>

            <!-- Used to include all of the dependencies in the packaged Jar file -->
            <plugin>
                <artifactId>maven-assembly-plugin</artifactId>
                <configuration>
                    <archive>
                        <manifest>
                            <mainClass>com.valkryst.Example.Driver</mainClass>
                        </manifest>
                    </archive>
                    <descriptorRefs>
                        <descriptorRef>jar-with-dependencies</descriptorRef>
                    </descriptorRefs>
                </configuration>
                <executions>
                    <execution>
                        <id>make-assembly</id> <!-- this is used for inheritance merges -->
                        <phase>package</phase> <!-- bind to the packaging phase -->
                        <goals>
                            <goal>single</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

This script uses jpackage to generate the MSI installer.

mkdir temp
mklink "%~dp0temp\Example-1.0-SNAPSHOT-jar-with-dependencies.jar" "%~dp0..\..\target\Example-1.0-SNAPSHOT-jar-with-dependencies.jar"

"C:\Program Files\Java\jdk-14\bin\jpackage.exe" ^
--type msi ^
--app-version "1.0.0" ^
--copyright "Valkryst, 2020" ^
--name "Example" ^
--vendor "Valkryst" ^
--verbose ^
--icon "%~dp0..\..\res\icon\icon.ico" ^
--input "%~dp0temp" ^
--java-options "-Djdk.module.illegalAccess=permit" ^
--main-class "com.valkryst.Example.Driver" ^
--main-jar "Example-1.0-SNAPSHOT-jar-with-dependencies.jar" ^
--win-dir-chooser ^
--win-shortcut ^
--win-console

del "%~dp0temp\Example-1.0-SNAPSHOT-jar-with-dependencies.jar"
rmdir "%~dp0temp
pause

This is the output from step #4.

PS C:\Program Files\Example> .\Example.exe
Error: Could not find or load main class com.valkryst.Example.Driver
Caused by: java.lang.ClassNotFoundException: com.valkryst.Example.Driver
Solution

  • After further investigation, it appears as though the jpackage utility doesn't support symbolic links. It wasn't packaging the Example-1.0-SNAPSHOT-jar-with-dependencies.jar into the executable, so the installed Example-1.0.0.exe was unable to load the main Driver class because it didn't exist in the installation directory.

    mkdir temp
copy "%~dp0..\..\target\Example-1.0-SNAPSHOT-jar-with-dependencies.jar" "%~dp0temp\Example-1.0-SNAPSHOT-jar-with-dependencies.jar"

"C:\Program Files\Java\jdk-14\bin\jpackage.exe" ^
--type msi ^
--app-version "1.0.0" ^
--copyright "Valkryst, 2020" ^
--name "Example" ^
--vendor "Valkryst" ^
--verbose ^
--icon "%~dp0..\..\res\icon\icon.ico" ^
--input "%~dp0temp" ^
--java-options "-Djdk.module.illegalAccess=permit" ^
--main-class "com.valkryst.Example.Driver" ^
--main-jar "Example-1.0-SNAPSHOT-jar-with-dependencies.jar" ^
--win-dir-chooser ^
--win-shortcut ^
--win-console

rmdir /S /Q "%~dp0temp
pause