Unsign a JAR with Ant

unsignjar.xml

<!-- http://frank.zinepal.com/unsign-a-jar-with-ant -->
<macrodef name="unsignjar">
        
    <attribute name="jar"/>
            
    <sequential>
        <!-- Remove any existing signatures from a JAR file. -->
        <tempfile prefix="usignjar-" destdir="${java.io.tmpdir}" property="temp.file"/>
        <echo message="Removing signatures from JAR: @{jar}"/>
        <mkdir dir="${temp.file}"/>
                
        <unjar src="@{jar}" dest="${temp.file}">
            <patternset>
                <include name="**"/>
                <exclude name="META-INF/*.SF"/>
                <exclude name="META-INF/*.DSA"/>
                <exclude name="META-INF/*.RSA"/>
            </patternset>
        </unjar>
                
        <delete file="@{jar}" failonerror="true"/>
                
        <!-- Touch it in case the file didn't have a manifest.
             Otherwise the JAR task below will fail if the manifest 
             file doesn't exist. -->
        <mkdir dir="${temp.file}/META-INF"/>
        <touch file="${temp.file}/META-INF/MANIFEST.MF"/>
                
        <jar destfile="@{jar}" 
            basedir="${temp.file}" 
            includes="**" 
            manifest="${temp.file}/META-INF/MANIFEST.MF"/>
                
        <delete dir="${temp.file}" failonerror="true"/>
    </sequential>
</macrodef>

<!--unsign single jar -->
<unsignjar jar="/some/location/file.jar"/>

<!--unsign and then re-sign fileset -->
<for param="file">
    <path>
        <fileset dir="lib" includes="**/*.jar"/>
    </path>
    <sequential>
        <antcall target="unsignjar">
            <param name="jar" value="@{file}"/>
        </antcall>
        <signjar
            jar="@{file}"
            alias="myalias"
            storepass="mypass"
            keystore="keystore"/>
    </sequential>
</for>

Awesome. :)