system class loader can not find initial class of working program

Name: szC45993 Date: 05/24/98



The
vm/constantpool/ClassInterf/ClassInterf021/ClassInterf02101/ClassInterf02101.html
vm/constantpool/ClassInterf/ClassInterf023/ClassInterf02301/ClassInterf02301.html
vm/constantpool/ClassInterf/ClassInterf025/ClassInterf02501/ClassInterf02501.html
vm/constantpool/ClassInterf/ClassInterf028/ClassInterf02801/ClassInterf02801.html
vm/constantpool/ClassInterf/ClassInterf029/ClassInterf02901/ClassInterf02901.html
vm/constantpool/ClassInterf/ClassInterf030/ClassInterf03001/ClassInterf03001.html
vm/constantpool/ClassInterf/ClassInterf032/ClassInterf03201/ClassInterf03201.html
vm/constantpool/ClassInterf/ClassInterf033/ClassInterf03301/ClassInterf03301.html
vm/constantpool/ClassInterf/ClassInterf037/ClassInterf03701/ClassInterf03701.html
vm/constantpool/ClassInterf/ClassInterf040/ClassInterf04001/ClassInterf04001.html
vm/constantpool/ClassInterf/ClassInterf044/ClassInterf04401/ClassInterf04401.html
vm/constantpool/ClassInterf/ClassInterf045/ClassInterf04501/ClassInterf04501.html
vm/constantpool/ClassInterf/ClassInterf046/ClassInterf04601/ClassInterf04601.html
vm/constantpool/ClassInterf/ClassInterf057/ClassInterf05701/ClassInterf05701.html
vm/constantpool/ClassInterf/ClassInterf056/ClassInterf05601/ClassInterf05601.html
tests show
that jdk1.2b4C erroneously uses non-system class loader for the loading
of the initial class of java program (it contradicts to vm spec).
Besides of that, may be as consequence of this,
SYSTEM CLASS LOADER CAN NOT FIND INITIAL CLASS OF WORKING PROGRAM when system
loader is used inside own class loader of this program.

Short test placed below demonstrates the incorrect jvm behaviour:

novo7% /export/ld14/java/dest/jdk1.2b4G/solaris/bin/javac ClassInterf02101.java
novo7% /export/ld14/java/dest/jdk1.2b4G/solaris/bin/java -verify ClassInterf02101

ERROR1: Class loader of initial class must be system class loader (i.e. the following must be true: getClassLoader() == null) but really class loader of initial class is sun.misc.Launcher$AppClassLoader@1903304a

(((loadClass: ClassInterf02101


findSystemClass correctly belongs to the system class loader (getClassLoader= null)

(((findSystemClass: ClassInterf02101
java.lang.ClassNotFoundException: ClassInterf02101

ERROR3: System class loader (findSystemClass) used by user class loader has not found initial class of running java program.

novo7%

SOURCE:


--------------------- ClassInterf02101.java
import java.io.PrintStream;
import java.util.*;

class myClassLoader extends java.lang.ClassLoader {
  Hashtable cache = new Hashtable();

  public synchronized Class loadClass(String name, boolean resolve) {
Class c = (Class) cache.get(name);

/**/ ClassInterf02101.o.println(" (((loadClass: "+name);


ClassInterf02101.o.println();
try{
if (findSystemClass("java/lang/Class").getClassLoader() == null) {
ClassInterf02101.o.println();
ClassInterf02101.o.println("findSystemClass correctly belongs to the system class loader (getClassLoader= "+findSystemClass("java/lang/Class").getClassLoader()+")");
} else {
ClassInterf02101.o.println("ERROR2: findSystemClass erroneously belongs to non-system class loader (getClassLoader= "+findSystemClass("java/lang/Class").getClassLoader()+")");
}
}
catch (java.lang.Throwable e) {
ClassInterf02101.o.println(e);
};
ClassInterf02101.o.println();
if (c == null) {
try{
/**/ ClassInterf02101.o.println(" (((findSystemClass: "+name);
c = findSystemClass(name);
/**/ ClassInterf02101.o.println(" )))findSystemClass: "+name);
}
catch (java.lang.ClassNotFoundException e) {
ClassInterf02101.o.println(" "+e);
return null;
};
cache.put(name, c);
return c;
}

if (resolve){
/**/ ClassInterf02101.o.println(" (((resolveClass: "+c);
resolveClass(c);
/**/ ClassInterf02101.o.println(" )))resolveClass: "+c);
}

/**/ ClassInterf02101.o.println(" )))loadClass: "+name);
return c;
  }

}

public class ClassInterf02101 {

  public static PrintStream o;

  public static int run(String argv[], PrintStream out) {
    try{
myClassLoader mcl = new myClassLoader();

o = out;

if (ClassInterf02101.class.getClassLoader() != null) {
out.println();
out.println("ERROR1: Class loader of initial class must be system class loader (i.e. the following must be true: getClassLoader() == null) but really class loader of initial class is "+ClassInterf02101.class.getClassLoader());
out.println();
}
try{
if (mcl.loadClass("ClassInterf02101", true) == (Class) null) {
out.println();
out.println("ERROR3: System class loader (findSystemClass) used by user class loader has not found initial class of running java program.");
out.println();
return 2;
}
}
catch (java.lang.Throwable e) {
out.println(" "+e);
return 2;
};

return 0;

    } catch (SecurityException e) {
out.println(" "+e);
out.println("Could not setup test.");
return 0;
    }
  }

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

}
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Hook 5(hook5): test

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