how to create a bundled runnable jar using Ant

Question

I looked at this question, but it didn't really solve my problem, so I figured I'd post a new one.

I need to create a runnable jar (runnable simply by double clicking) using Ant. I have the following java code and build.xml file, which compiles the code just fine and creates a jar file, but when I try to run the jar by double clicking, i get a message saying "Could not find main class: HttpController.java."

I have the suspicion that my problem has to do with loading the external Apache Http.jar, as I have successfully built and run a jar for a project that is identical, except that it does not reference any external jars.

Here is my code:

HttpController.java:

package pack;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

import org.apache.http.HttpEntity;
import org.apache.http.HttpHost;
import org.apache.http.HttpMessage;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

public class HttpController {
        public static void main(String[] args) {

        DefaultHttpClient client = new DefaultHttpClient();
        HttpHost httphost = new HttpHost("localhost", 80);

        try {

            HttpMessage req = new HttpGet("/test.html");
            HttpResponse resp = client.execute(httphost, (HttpGet) req);
            HttpEntity entity = resp.getEntity();

            BufferedReader in = new BufferedReader(new InputStreamReader(
                    entity.getContent()));

            String line = null;
            while ((line = in.readLine()) != null) {
                System.out.println(line);
            }

        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            // shutdown the connection
            client.getConnectionManager().shutdown();
        }
    }
}

build.xml:

    <?xml version="1.0" encoding="ISO-8859-1"?>
    <project name="Test" basedir="." default="jar">
    <property name="source.dir"     value="src"/>
    <property name="lib.dir"        value="lib"/>
    <property name="class.dir"      value="bin"/>
    <property name="jar.dir"        value="dist"/>
    <property name="main-class"     value="pack.HttpController"/>

    <path id="libraries.path">    
        <fileset dir="${lib.dir}">
            <include name="*.jar"/>
        </fileset>
    </path>

    <target name="clean" description="delete old files">
        <delete dir="${class.dir}"/>
        <delete dir="${jar.dir}"/>
    </target>

    <target name="compile" description="build class files" depends="clean">
        <mkdir dir="${class.dir}"/>
        <javac srcdir="${source.dir}" destdir="${class.dir}">
            <classpath refid="libraries.path"/>
        </javac>
    </target>

    <target name="jar" depends="compile">
        <mkdir dir="${jar.dir}"/>
        <mkdir dir="${jar.dir}/${lib.dir}"/>
        <copy todir="${jar.dir}/${lib.dir}" flatten="true">
            <path refid="libraries.path"/>
        </copy>
        <jar destfile="${jar.dir}/${ant.project.name}.jar" basedir="${class.dir}">
            <manifest>
                <attribute name="Main-Class" value="${main-class}"/>
                <attribute name="Class-Path" value="${jar.dir}/${lib.dir}/Apache HTTP.jar"/>
            </manifest>
        </jar>  
    </target>

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

MANIFEST.MF:

Manifest-Version: 1.0
Ant-Version: Apache Ant 1.8.3
Created-By: 1.6.0_31-b05 (Sun Microsystems Inc.)
Main-Class: HttpController
Class-Path: dist/lib

EDIT build.xml has been updated as per Mike's answer. Problem is still not solved. Also posted contents of manifest file, as per Danation's answer.

Answer 1

Snip...

I have reworked your build.xml file to properly include the libraries in the jar file and in the Manifest classpath. I'm assuming that your "apache http.jar" file is a wrapper for Apache Core, and contains several other jar files in it for the apache client, etc.

build.xml

<?xml version="1.0" encoding="ISO-8859-1"?>
<project name="Test" basedir="." default="jar">
    <property name="source.dir"     value="src"/>
    <property name="lib.dir"        value="lib"/>
    <property name="class.dir"      value="bin"/>
    <property name="jar.dir"        value="dist"/>
    <property name="jar.file"        value="${jar.dir}/${ant.project.name}.jar"/>
    <property name="main-class"     value="pack.HttpController"/>

    <path id="libraries.path">    
        <fileset dir="${lib.dir}">
            <include name="*.jar"/>
        </fileset>
    </path>

    <target name="clean" description="delete old files">
        <delete dir="${class.dir}"/>
        <delete dir="${jar.dir}"/>
    </target>

    <target name="compile" description="build class files" depends="clean">
        <mkdir dir="${class.dir}"/>
        <javac srcdir="${source.dir}" destdir="${class.dir}">
            <classpath refid="libraries.path"/>
        </javac>
    </target>

    <target name="jar" depends="compile">
        <mkdir dir="${jar.dir}"/>
        <mkdir dir="${class.dir}/${lib.dir}"/>
        <copy todir="${class.dir}/${lib.dir}" flatten="true">
            <path refid="libraries.path"/>
        </copy>

        <manifestclasspath property="manifest.classpath" jarfile="${jar.file}">
            <classpath refid="libraries.path"/>
        </manifestclasspath>

        <jar destfile="${jar.file}" basedir="${class.dir}">
            <manifest>
                <attribute name="Main-Class" value="${main-class}"/>
                <attribute name="Class-Path" value="${manifest.classpath}"/>
            </manifest>
        </jar>  
    </target>

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

</project>

Answer 2

Your Class-Path entry is wrong, you have to specify each jar file individually, you cannot specify a directory with .jar files (only directories with .class files)

This is documented in the JAR File specification and explained quite nicely in the Java tutorial

If you have two libraries name FirstLib.jar and SeconLib.jar your Class-Path entry should look like this:

Class-Path: lib/FirstLib.jar lib/SecondLib.jar 

Edit:
Inside your build.xml this would look like this:

<jar destfile="${jar.dir}/${ant.project.name}.jar" basedir="${class.dir}">
    <manifest>
        <attribute name="Main-Class" value="${main-class}"/>
        <attribute name="Class-Path" value="${lib.dir}/FirstLib.jar ${lib.dir}/SecondLib.jar"/>
    </manifest>
</jar>