Name: akC45999 Date: 07/06/98



The Java VM spec chapter "4.6 Methods" reads:
...
Is abstract; no implementation is provided.

But the attached test shows that VM doesn't reject a class which contain an abstract method with Code attribute.

--------------------------------- test.java

import java.io.PrintStream;

public class test {
  
  public static void main(String argv[]) {

try {
Class.forName("BadClass");
System.out.println("Very bad");
} catch (Throwable e) {
System.out.println("Exception " + e);
}
  }
}

--------------------------------- BadClass.jasm

abstract class BadClass
{

abstract Method "testMethod":"()V"
{
return;
}
}

------------------------------------- dotest

#!/bin/sh
TESTCLASSES=/opt/home/testclasses
CLASSPATH=$TESTCLASSES
export CLASSPATH

jasm -d $TESTCLASSES *.jasm
javac -d $TESTCLASSES *.java
java -verify test;

----------------------------------------
Running the test:

novo48% dotest
Very bad
novo48%
======================================================================

======================================================================

Name: akC45999 Date: 07/07/98



The Java VM spec chapter "4.6 Methods" reads:
...
If the method is either native or abstract, its method_info structure must not have a Code attribut.

But the attached test shows that VM doesn't reject a class which contain an abstract method with Code attribute.

--------------------------------- test.java

import java.io.PrintStream;

public class test {
  
  public static void main(String argv[]) {

try {
Class.forName("BadClass");
System.out.println("Very bad");
} catch (Throwable e) {
System.out.println("Exception " + e);
}
  }
}

--------------------------------- BadClass.jasm

abstract class BadClass
{

abstract Method "testMethod":"()V"
{
return;
}
}

------------------------------------- dotest

#!/bin/sh
TESTCLASSES=/opt/home/testclasses
CLASSPATH=$TESTCLASSES
export CLASSPATH

jasm -d $TESTCLASSES *.jasm
javac -d $TESTCLASSES *.java
java -verify test;

----------------------------------------
Running the test:

novo48% dotest
Very bad
novo48%
======================================================================

======================================================================

Name: akC45999 Date: 07/07/98



The Java VM spec chapter "4.6 Methods" reads:
...
If the method is either native or abstract, its method_info structure must not have a Code attribute.

But the attached test shows that VM doesn't reject a class which contain an abstract method with Code attribute.

--------------------------------- test.java

import java.io.PrintStream;

public class test {
  
  public static void main(String argv[]) {

try {
Class.forName("BadClass");
System.out.println("Very bad");
} catch (Throwable e) {
System.out.println("Exception " + e);
}
  }
}

--------------------------------- BadClass.jasm

abstract class BadClass
{

abstract Method "testMethod":"()V"
{
return;
}
}

------------------------------------- dotest

#!/bin/sh
TESTCLASSES=/opt/home/testclasses
CLASSPATH=$TESTCLASSES
export CLASSPATH

jasm -d $TESTCLASSES *.jasm
javac -d $TESTCLASSES *.java
java -verify test;

----------------------------------------
Running the test:

novo48% dotest
Very bad
novo48%

======================================================================

======================================================================