problems with a simple HelloWorld.jar

Ninca · Mar 15, 2007

I know such questions have been posted a lot, but I read the answers to some and still got the same problem:

I can`t produce a simple jar-File:

Typing ant jar results in:

Buildfile: build.xml
init:
compile:
jar:
[jar] Warning: skipping jar archive AntHelloWorld\jar\HelloWorld.jar because no files were included.

BUILD SUCCESSFUL
Total time: 0 seconds

Typing java -jar jar/HelloWorld.jar results in:
Exception in thread "main" java.lang.NoClassDefFoundError: HelloWorld

In the HelloWorld.jar is only the Manifst.MF included, this looks like:
Manifest-Version: 1.0
Ant-Version: Apache Ant 1.7.0
Created-By: 1.6.0-b105 (Sun Microsystems Inc.)
Main-Class: HelloWorld

The HelloWorld.java is directly in the folder java.
The build.xml looks like:


<project name="AntHelloWorld" default="jar" basedir=".">
<description>Test
</description>


<property name="java" location="java"/>
<property name="class" location="class"/>
<property name="jar" location="jar"/>


<target name="init">
<tstamp>
<format property="TODAY_UK" pattern="MM-dd-yyyy" locale="en"/>
</tstamp>
<mkdir dir="$(class)"/>
<mkdir dir="$(jar)"/>
</target>


<target name="compile" depends="init">
<javac srcdir="${java}" destdir="${class}">
</javac>
</target>


<target name="jar" depends="compile">
<jar jarfile="${jar}/HelloWorld.jar"
basedir="$(class)"
includes="**/*.class">
<manifest>
<attribute name="Main-Class" value="HelloWorld"/>
</manifest>
</jar>
</target>


<target name="run" depends="jar">
<java jar="${jar}/HelloWorld.jar" fork="true">
</java>
</target>


<target name="clean">
<delete dir="${class}"/>
<delete dir="${jar}"/>
</target>

</project>

Can somebody help me?

timw · Mar 15, 2007

It may sound like a daft question, but can you confirm that the java file(s) compiled okay? If you do an ant compile do you get any .class files in the class directory?

Tim

Ninca · Mar 15, 2007

Yes, of course, the HelloWorld.class is put in the folder class. To be sure, I just tried out ant compile (before I had deleted the .class file).

In the main-method of the HelloWorld.java is only an
System.out.println("HelloWorld");

timw · Mar 15, 2007

Mmmm. Try

Code:

<target name="jar" depends="compile">
   <jar jarfile="${jar}/HelloWorld.jar"
        basedir="[b]${class}[/b]"
        includes="**/*.class">
      <manifest>
         <attribute name="Main-Class" value="HelloWorld"/>
      </manifest>
   </jar>
</target>

You need the curly braces instead of ordinary parentheses.

Tim

Ninca · Mar 15, 2007

Thanks a lot!

It works now(with curly braces instead of ordinary parentheses)!

Ninca

timw · Mar 15, 2007

One tip, Ninca. I would have spotted that much sooner had you not posted the script in the colour you did. It's always best to put code and scripts in a post with the TGML code tags as I did in my last post above. Much easier on the eye.

Tim

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problems with a simple HelloWorld.jar

Ninca

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timw

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Ninca

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timw

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Ninca

Programmer

timw

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