How to unzip file that that is not in UTF8 format in java

Question

I have a file e.g. test.zip. If I use a ZIP-tool like winrar, it's easy to extract (unzip test.zip to test.csv). But test.csv is not in UTF8 format. My problem here is, when I use java to unzip it, it can't read this file.

ZipFile zf = new ZipFile("C:/test.zip");

The thrown exception says that there occurs an error by opening that file.

On java http://java.sun.com/developer/technicalArticles/Programming/compression/ is nothing written about data formatting. Maybe the whole API is designed only for UTF8-format data. So, if I have to unzip data except UTF8 format, how to unzip it? Especially the japanese and chinese characters that holds more space size (except UTF8). I also found an API at http://truezip.java.net/6/tutorial.html where this problem is mentioned. But, I didn't get a way on how to solve it. Is there any simple way to solve this problem? Especially from the API that is passed from JAVA specification request.

Answer 1

JDK6 has a bug in java.util.zip implementation it cannot handle non-USASCII characters. I use Apache Commons commons-compress-1.0.jar library to fix it. JDK7 has fixed java.util.zip implementation. http://docs.oracle.com/javase/7/docs/api/java/util/zip/ZipInputStream.html

import java.io.*;
import org.apache.commons.compress.archivers.ArchiveEntry;
import org.apache.commons.compress.archivers.zip.*;

public static int unzip(File inputZip, File outputFolder) throws IOException {
    int count=0;
    FileInputStream fis = null;
    ZipArchiveInputStream zis = null;
    FileOutputStream fos = null;
    try {
        byte[] buffer = new byte[8192];
        fis = new FileInputStream(inputZip);
        zis = new ZipArchiveInputStream(fis, "Cp1252", true); // this supports non-USACII names
        ArchiveEntry entry;
        while ((entry = zis.getNextEntry()) != null) {
            File file = new File(outputFolder, entry.getName());
            if (entry.isDirectory()) {
                file.mkdirs();
            } else {
                count++;
                file.getParentFile().mkdirs();
                fos = new FileOutputStream(file);
                int read;
                while ((read = zis.read(buffer,0,buffer.length)) != -1)
                    fos.write(buffer,0,read);
                fos.close();
                fos=null;
            }
        }
    } finally {
        try { zis.close(); } catch (Exception e) { }
        try { fis.close(); } catch (Exception e) { }
        try { if (fos!=null) fos.close(); } catch (Exception e) { }
    }
    return count;
}