Name: akC45999 Date: 06/01/98



The Java VM spec chapter 5.3.1 Loading Using the Default Class Loader reads:
...
5.This phase of loading must detect the following errors:
       If the purported representation is not in ClassFile format (§4.1,
       pass 1 of §4.9.1), or is not of a supported major or minor version
       (§4.1), loading throws a ClassFormatError.
       Otherwise, if the purported representation does not actually
       represent C, loading throws an instance of
       NoClassDefFoundError or an instance of one of its subclasses.

But the attached test shows that ClassFormatError is thrown when "the purported
representation does not actually represent C", that is, the name stored in the class file
differs from the file name.

--------------------------------- defaultLoader00301.java

import java.io.PrintStream;

public class defaultLoader00301 {

  public static int run(String argv[], PrintStream out) {

try{
Class.forName("BadClass");
out.println("No exception ");
return 2;
} catch (NoClassDefFoundError e) {
return 0;
} catch (Throwable e) {
out.println("Unexpected exception " + e);
return 2;
}
  }

  public static void main(String argv[]) {
System.exit(run(argv, System.out) + 95/*STATUS_TEMP*/);
  }

} // end class defaultLoader00301

--------------------------------- BadClass.jcod
class BadClass {
  0xCAFEBABE;
  3; // minor version
  45; // version
  [] { // Constant Pool
    ; // first element is empty
    class #7; // #1
    class #12; // #2
    Method #2 #4; // #3
    NameAndType #6 #5; // #4
    Utf8 "()V"; // #5
    Utf8 "<init>"; // #6
// Utf8 "BadClass"; // #7 // right
    Utf8 "BadClassName"; // #7 // wrong
    Utf8 "BadClass.java"; // #8
    Utf8 "Code"; // #9
    Utf8 "I"; // #10
    Utf8 "aField"; // #11
    Utf8 "java/lang/Object"; // #12
  } // Constant Pool

  0x0020; // access
  #1;// this_cpx
  #2;// super_cpx

  [] { // Interfaces
  } // Interfaces

  [] { // fields
    { // Member
      0x0008; // access
      #11; // name_cpx
      #10; // sig_cpx
      [] { // Attributes
      } // Attributes
    } // Member
  } // fields

  [] { // methods
  } // methods

  [] { // Attributes
  } // Attributes
} // end class BadClass
------------------------------------- runtest
#!/bin/ksh

javac defaultLoader00301.java
jcoder BadClass.jcod
java -verify defaultLoader00301
echo res=$?
----------------------------------------
Running the test:

novo64% runtest
Unexpected exception java.lang.ClassFormatError: BadClass (Wrong name: BadClassName)
res=97
novo64%


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