Taskdef class com.temp.install.common.action.UserInstallDirRule cannot be found using the classloader AntClassLoader

Question

I have created a jar with the .class files and the dependency libraries which are required for executing the class files using the below jar code

<target name="jar" depends="clean">
    <jar destfile="${basedir}/lib/HelloWorld.jar">
        <zipgroupfileset dir="${basedir}/lib" includes="*.jar" />
        <fileset dir="${basedir}" includes="/com/temp/**" />
        <fileset dir="${basedir}" includes="build.properties"/>
        <manifest>
        <attribute name="Class-Path" value="./HelloWorld.jar"/>
        </manifest>
    </jar>
</target>

Now i have written other build.xml to run taskdef actions using this jar but the following error occurs when i try to invoke the class files using the taskdef actions even though the class files and their dependencies are present in the same jar.

BUILD FAILED C:\Users\kh2139\Desktop\New folder\build.xml:4: taskdef class com.temp.install.common.action.UserInstallDirRule cannot be found using the classloader AntClassLoader[C:\Users\kh2139\Desktop\New folder\HelloWorld.jar]

Attaching my build.xml code below which is used to run taskdef actions on the HelloWorld.jar

<?xml version="1.0" encoding="ISO-8859-1"?>
    <project name="MyTask" basedir="." default="use">
<target name="use" description="Use the Task" >
    <taskdef name="helloworld1" classname="com.temp.install.common.action.UserInstallDirRule" classpath="HelloWorld.jar"/>
    <helloworld1/>
    <taskdef name="helloworld" classname="com.temp.install.common.action.EncryptionGUID" classpath="HelloWorld.jar"/>
    <helloworld/>
</target>
</project>

PS: I could able to run the build.xml file successfully without errors when i specify the lib folder in the location where i place HelloWorld.jar and give the classpath to the lib folder in the taskdef actions.

But my issue is i want to use the same jar to contain the dependencies that are used while executing the classes.

Answer 1

The error indicates that Java cannot find UserInstallDirRule.class in HelloWorld.jar. To determine if HelloWorld.jar contains the class, try running the jar.exe program included with the JDK.

Here's an example of running jar.exe in a Windows Command Prompt:

C:\>jar.exe tf "C:\Users\kh2139\Desktop\New folder\HelloWorld.jar"

The output will show whether UserInstallDirRule.class is in the JAR file.