JarURLConnection.getJarFile() resource leak when file is not found

[Neon Ngo]

The test program below shows a resource leak in
java.net.JarURLConnection's getJarFile() when given an non-existent
file to lookup in the jar file.

Under Windows, the last printout shows that it is not able to remove
the test input jar file.
Any input jar file can be used to test this as long as it does not
contain "/testNonExistentFile.xyz" in the jar file.

Warning, this test program will try to delete the input file, so use
with a "temporary" copy of an existing jar file.

This happens under all current Oracle and OpenJDK Java versions: 6, 7,
and 8 (I have not tried beta versions of 9).

I could not find a matching BUG for this issue on both the Oracle and
OpenJDK websites.
So would like to start the conversation here since my submission on
the Oracle website almost a month ago seems to have been lost.

Anyone know of a workaround for this issue?

Regards,

Neon

=== test.java ===
package nxm.test.lib;

import java.io.File;
import java.net.JarURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.util.jar.JarFile;

public class test {

  public static void getJarFile(String urlstr) throws Exception {
    System.out.println("testing URL: " + urlstr);
    URL url = new URL(urlstr);
    URLConnection urlConnection = url.openConnection();
    if (urlConnection instanceof JarURLConnection) {
      JarURLConnection jarUrlConnection = (JarURLConnection) urlConnection;
      JarFile jarFile = jarUrlConnection.getJarFile();
      System.out.println(" Got JarFile  : " + jarFile);
      System.out.println(" JarFile.name : " + ((jarFile != null) ?
jarFile.getName() : ""));
      jarFile.close();
      System.out.println(" Closed JarFile " + jarFile);

    } else if (urlConnection != null) {
      System.err.println(" URLConnection.class: " + urlConnection.getClass());
    }
  }

  public static void main(String[] args) {
    if (args.length < 1) {
      error("Usage: <file.jar>");
    }
    String jarFilename = args[0];
    File file = new File(jarFilename);
    if (!file.exists()) {
      error("input jar file does not exists: " + file);
    }

    String nonExistentFileInJar = "jar:file:" + jarFilename +
"!/testNonExistentFile.xyz";
    try {
      getJarFile(nonExistentFileInJar);
    } catch (Exception e) {
      e.printStackTrace();
    }

    boolean result = file.delete();
    System.out.println("Able to remove test jar file? " + result);

    if (!result) {
      error("Unable to remove test jar file: " + jarFilename);
    }
  }

  static void error(String msg) {
    System.err.println(msg);
    System.exit(1);
  }
}

=== end test.java ===
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.openjdk.java.net/pipermail/net-dev/attachments/20150817/50d98017/attachment.html>