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  1. JDK
  2. JDK-8016445

UnsupportedClassVersionError should be more informative

    Details

    • Type: Bug
    • Status: Closed
    • Priority: P3
    • Resolution: Duplicate
    • Affects Version/s: 7
    • Fix Version/s: None
    • Component/s: hotspot
    • Labels:

      Description

      FULL PRODUCT VERSION :
      any

      EXTRA RELEVANT SYSTEM CONFIGURATION :
      Current version of JRE, Beta version of JDK

      A DESCRIPTION OF THE PROBLEM :
      Developers using the newest version of Java are penalized by users who think there is a problem in the developer's code. The code returned is rather obscure and appears to be a problem with the code at first glance.

      The problem is that the user automatically assumes that the code is flawed. I see this error coming up repeatedly because I develop on Java 1.7 and I release nightly. When users run my application, they are greeted with an exception so they send me a bug report. Because my application isn't even running, I get spammed with text instead of my own logging system.

      This is a horrible way to say " Java is out of date " .

      STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
      java -jar path_to/LatestJava.jar

      EXPECTED VERSUS ACTUAL BEHAVIOR :
      EXPECTED -
        " Java attempted to launch this app with API Level 47, but Level 51 is needed to run this application. A Java update is required. "

      ERROR MESSAGES/STACK TRACES THAT OCCUR :
      Exception in thread " main " java.lang.UnsupportedClassVersionError: CASUAL/CASUALApp : Unsupported major.minor version 51.0
      at java.lang.ClassLoader.defineClass1(Native Method)
      at java.lang.ClassLoader.defineClass(ClassLoader.java:634)
      at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
      at java.net.URLClassLoader.defineClass(URLClassLoader.java:277)
      at java.net.URLClassLoader.access$000(URLClassLoader.java:73)
      at java.net.URLClassLoader$1.run(URLClassLoader.java:212)
      at java.security.AccessController.doPrivileged(Native Method)
      at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:321)
      at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
      Could not find the main class: CASUAL.CASUALApp. Program will exit.

      REPRODUCIBILITY :
      This bug can be reproduced always.

      ---------- BEGIN SOURCE ----------
      Compile this on a new version of Java and run it on an older version.


      public static void main(String[] args) {}
      ---------- END SOURCE ----------

      CUSTOMER SUBMITTED WORKAROUND :
      There is no way to work around this issue. Code will not launch at this point.

      Suggestion:
      Parse the exception for " Unsupported major.minor version " and just output the text if run from command line.

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              • Assignee:
                Unassigned
                Reporter:
                webbuggrp Webbug Group
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                Dates

                • Created:
                  Updated:
                  Resolved: