Uploaded image for project: 'JDK'
  1. JDK
  2. JDK-8155607

Closing an URLClassLoader instance affect another URLClassLoader instance when getResourceAsStream() is being used

    Details

    • Subcomponent:
    • CPU:
      generic
    • OS:
      generic

      Description

      FULL PRODUCT VERSION :
      java version "1.8.0_92"
      Java(TM) SE Runtime Environment (build 1.8.0_92-b14)
      Java HotSpot(TM) 64-Bit Server VM (build 25.92-b14, mixed mode)

      ADDITIONAL OS VERSION INFORMATION :
      Darwin Terences-MacBook-Pro.local 15.4.0 Darwin Kernel Version 15.4.0: Fri Feb 26 22:08:05 PST 2016; root:xnu-3248.40.184~3/RELEASE_X86_64 x86_64

      A DESCRIPTION OF THE PROBLEM :
      When having two different instances of URLClassLoader sharing the same set of URLs, closing one instance will close the InputStream returned by getResourceAsStream() from another URLClassLoader instance.

      STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
      With the simple application posted in "Source code for an executable test case", compile it and run it.

      1. javac SimpleTest.java
      2. java SimpleTest

      EXPECTED VERSUS ACTUAL BEHAVIOR :
      EXPECTED -
      First stream: sun.net.www.protocol.jar.JarURLConnection$JarURLInputStream@3cd1a2f1
      Second stream: sun.net.www.protocol.jar.JarURLConnection$JarURLInputStream@49476842
      ACTUAL -
      First stream: sun.net.www.protocol.jar.JarURLConnection$JarURLInputStream@3cd1a2f1
      Second stream: sun.net.www.protocol.jar.JarURLConnection$JarURLInputStream@49476842
      Exception in thread "main" java.io.IOException: Stream closed
      at java.util.zip.InflaterInputStream.ensureOpen(InflaterInputStream.java:67)
      at java.util.zip.InflaterInputStream.read(InflaterInputStream.java:121)
      at java.io.FilterInputStream.read(FilterInputStream.java:83)
      at SimpleTest.main(SimpleTest.java:53)

      ERROR MESSAGES/STACK TRACES THAT OCCUR :
      Exception in thread "main" java.io.IOException: Stream closed
      at java.util.zip.InflaterInputStream.ensureOpen(InflaterInputStream.java:67)
      at java.util.zip.InflaterInputStream.read(InflaterInputStream.java:121)
      at java.io.FilterInputStream.read(FilterInputStream.java:83)
      at SimpleTest.main(SimpleTest.java:53)

      REPRODUCIBILITY :
      This bug can be reproduced always.

      ---------- BEGIN SOURCE ----------
      import java.io.File;
      import java.io.FileOutputStream;
      import java.io.InputStream;
      import java.net.URL;
      import java.net.URLClassLoader;
      import java.util.jar.JarEntry;
      import java.util.jar.JarOutputStream;

      public class SimpleTest {

        public static void main(String[] args) throws Exception {
          // Generate a jar file with a file inside
          File jarFile = File.createTempFile("test", ".jar");
          try {
            try (JarOutputStream jarOutput = new JarOutputStream(new FileOutputStream(jarFile))) {
              jarOutput.putNextEntry(new JarEntry("file.txt"));
              jarOutput.write("Hello World".getBytes("UTF-8"));
              jarOutput.closeEntry();
            }

            // Define two different instances of URLClassLoader from the same set of urls.
            URL[] urls = new URL[]{ jarFile.toURI().toURL() };
            URLClassLoader cl1 = new URLClassLoader(urls, null);
            URLClassLoader cl2 = new URLClassLoader(urls, null);

            // Open a resource stream from the first CL
            try (InputStream is = cl1.getResourceAsStream("file.txt")) {
              System.out.println("First stream: " + is);
            }

            // Open another resource stream from the second CL, with the same resource name
            try (InputStream is = cl2.getResourceAsStream("file.txt")) {
              System.out.println("Second stream: " + is);
              while (is.read() >= 0) {
                // While reading, close the first CL, the next is.read() will throw a "java.io.IOException: Stream closed"
                cl1.close();
              }
            }

            cl2.close();
          } finally {
            jarFile.delete();
          }
        }
      }

      ---------- END SOURCE ----------

        Attachments

          Issue Links

            Activity

              People

              • Assignee:
                chegar Chris Hegarty
                Reporter:
                webbuggrp Webbug Group
              • Votes:
                0 Vote for this issue
                Watchers:
                5 Start watching this issue

                Dates

                • Created:
                  Updated:
                  Resolved: