> [JDK-6956385](https://bugs.openjdk.org/browse/JDK-6956385): > `JarURLConnection` properly tracks any `InputStream` it itself opened, and > correspondingly closes the `JarFile` if necessary (when caches are disabled). > However if its underlying `FileURLConnection` was used to retrieve a header > field, that would have caused a `FileInputStream` to be opened which never > gets closed until it is garbage collected. This means that an application > which calls certain methods on `jar:file:/…something.jar!/…` URLs will leak > file handles, even if `URLConnection` caches are supposed to be turned off. > This can delay release of system resources, and on Windows can prevent the > JAR file from being deleted even after it is no longer in use (for example > after `URLClassLoader.close`). > > [JDK-8224095](https://bugs.openjdk.org/browse/JDK-8224095) was marked as a > duplicate, but I think incorrectly. It refers to `FileURLConnection`, and > seems to be complaining about the confusing API design of `URLConnection` > generally: that it is an object which you might expect to be `Closeable` but > in fact it is its `inputStream` which must be `close`d. In JDK-6956385, even > when the caller _does_ specifically call `InputStream.close`, a file handle > may be leaked. > > I managed to build the JDK on both Linux and (Cygwin) Windows to confirm the > fix via > > > ./build/…-x86_64-server-release/jdk/bin/java > test/jdk/sun/net/www/protocol/jar/FileURLConnectionLeak.java > > > I also ran jtreg on Linux (this test and various others in nearby packages); > on Windows the `make test` target just hung for some reason. > > I marked the test `othervm` out of caution, since it is mutating global > state, and if it fails will leak a handle and prevent scratch dir cleanup on > Windows. > > (This is my first contribution, at least after the move to GitHub, so let me > know if something is missing here technically or stylistically. None of the > contribution guides appear to be up to date.)
Jesse Glick has updated the pull request incrementally with one additional commit since the last revision: Leaving `FileURLConnection.is` non-null, and claiming `connected`, even after `closeInputStream` https://github.com/openjdk/jdk/pull/12871#discussion_r1199085883 ------------- Changes: - all: https://git.openjdk.org/jdk/pull/12871/files - new: https://git.openjdk.org/jdk/pull/12871/files/37b042c1..232e4f2e Webrevs: - full: https://webrevs.openjdk.org/?repo=jdk&pr=12871&range=02 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=12871&range=01-02 Stats: 2 lines in 1 file changed: 0 ins; 2 del; 0 mod Patch: https://git.openjdk.org/jdk/pull/12871.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/12871/head:pull/12871 PR: https://git.openjdk.org/jdk/pull/12871
