No overwrite on Ant UNZIP

I want to unzip a file, but if some file exists, this mustn´t be replaced.

I tried this:

<unzip src="compress.zip" dest="dirTo" overwrite="false">
<patternset>
    <include name="dirFrom/**"/>
</patternset>

"dirFrom", is the name from the directory IN the compress file, what I want to extract. I use "overwrite" to false, but it doesn´t work, and it ovewrites.

I have a directory, and this has different subdirectories. I want one of those subdirectories, with it´s files and sub-subdirectories.

Solution

I found how to do it.

1st, I extract everything to auxiliar directory. 2nd, I make a loop, to compare file by file, if that file exists. 3rd, If the file doesn´t exists, I copy it.

    <unzip src="compressFile.zip" dest="dirAux">
    <patternset>
        <include name="mySubDir/**"/>
    </patternset>
</unzip>

<fileset id="fileset1" dir="dirAux/mySubDir" />
<property name="newContentMySubDir" refid="fileset1"/>

<for param="nameFile" list="${newContentMySubDir}" delimiter=";">
    <sequential>

        <if>
            <not><available file="${finalDir}/mySubDir/@{nameFile}" type="file"/></not>
            <then>
                <copy tofile="${finalDir}/mySubDir/@{nameFile}" file="dirAux/mySubDir/@{nameFile}"/>
            </then>
        </if>

    </sequential>
</for>