Hello Patrick,
This is a known bug https://bugs.openjdk.org/browse/JDK-8315993 which
gets triggered when the getResource() gets called on a URL returned
through the URLClassLoader. We know what's causing this but the fix
isn't straightforward and is currently under investigation.
-Jaikiran
On 10/10/24 7:43 pm, Patrick Reinhart wrote:
Hi Everybody,
I recently stumbled over a strange behavior within the URLClassLoader under
Windows regarding a left open file handle even though everything is handled
within try-with-resources blocks.
Here is simple test that passes under Linux & Mac but fails under Windows:
import java.io.*;
import java.net.*;
import java.nio.file.*;
import java.util.jar.*;
public class TestURLClassLoader {
public static void main(String[] args) throws Exception {
var testJar = setupJar();
try (URLClassLoader cl = new URLClassLoader(new URL[] {
testJar.toUri().toURL() })) {
var testResource = cl.getResource("testResource");
assert testResource != null;
try (InputStream in = testResource.openStream()) {
in.transferTo(System.out);
}
}
Files.delete(testJar);
assert !Files.exists(testJar);
}
// setting up a simple .jar file with a single resource as example
private static Path setupJar() throws IOException {
var testJar = Paths.get("test.jar");
try (var out = new FileOutputStream("test.jar");
var jar = new JarOutputStream(out)) {
jar.putNextEntry(new JarEntry("testResource"));
var testData = "some data\n".getBytes();
jar.write(testData, 0, testData.length);
}
assert Files.exists(testJar);
return testJar;
}
}
