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  1. JDK
  2. JDK-4715300

(cl spec) spec describes inappropriate exception for ClassLoader.defineClass()

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      Name: vrR10176 Date: 07/16/2002



      The API spec for method ClassLoader.defineClass(String name, byte[] b,
      int off, int len, ProtectionDomain protectionDomain) reads:

      "If the name parameter is not null, it must be equal to the name of the class
      specified by the byte array b, otherwise a ClassFormatError is raised."

      But the API spec for ClassFormatError reads:
      "Thrown when the Java Virtual Machine attempts to read a class file and determines
      that the file is malformed or otherwise cannot be interpreted as a class file."

      So if byte array b describes valid class file, the exception ClassFormatError
      looks like inappropriate in this case. More consistent exception in this case
      is NoClassDefFoundError. It also conforms to JVMS-2 specification:

      "5.3.5 Deriving a Class from a class File Representation

         2.Otherwise, the Java virtual machine attempts to parse the purported representation.
           However, the purported representation may not in fact be a valid representation of C.
           This phase of loading must detect the following errors:
             -If the purported representation is not in class file format, loading throws an instance of ClassFormatError.
             -Otherwise, if the purported representation is not of a supported major or minor version, loading throws an
               instance of UnsupportedClassVersionError.
             -Otherwise, if the purported representation does not actually represent a class named N, loading throws an
               instance of NoClassDefFoundError or an instance of one of its subclasses."

      Moreover JDKs (jdk1.4.0-b92, jdk1.4.1-b15) throw NoClassDefFoundError if name is not equal
      to the name of the class specified by the byte array b.

      Likely ClassFormatError should be replaced with NoClassDefFoundError in mentioned JavaDoc assertion.

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            • Assignee:
              iris Iris Clark
              Reporter:
              rslasunw Rsla Rsla (Inactive)
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