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  1. Hadoop Common
  2. HADOOP-13410

RunJar adds the content of the jar twice to the classpath

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    Details

    • Type: Bug
    • Status: Resolved
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 3.0.0-alpha1
    • Component/s: util
    • Labels:
      None

      Description

      Today when you run a "hadoop jar" command, the jar is unzipped to a temporary location and gets added to the classloader.

      However, the original jar itself is still added to the classpath.

            List<URL> classPath = new ArrayList<>();
            classPath.add(new File(workDir + "/").toURI().toURL());
            classPath.add(file.toURI().toURL());
            classPath.add(new File(workDir, "classes/").toURI().toURL());
            File[] libs = new File(workDir, "lib").listFiles();
            if (libs != null) {
              for (File lib : libs) {
                classPath.add(lib.toURI().toURL());
              }
            }
      

      As a result, the contents of the jar are present in the classpath twice and are completely redundant. Although this does not necessarily cause correctness issues, some stricter code written to require a single presence of files may fail.

      I cannot think of a good reason why the jar should be added to the classpath if the unjarred content was added to it. I think we should remove the jar from the classpath.

        Attachments

        1. HADOOP-13410.002.patch
          1 kB
          Sangjin Lee
        2. HADOOP-13410.001.patch
          2 kB
          Yuanbo Liu

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              • Assignee:
                yuanbo Yuanbo Liu
                Reporter:
                sjlee0 Sangjin Lee
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                • Created:
                  Updated:
                  Resolved: