referencetype.java

代码是一个分类器的实现,其中使用了部分weka的源代码。可以将项目导入eclipse运行

package de.fub.bytecode.generic;
import de.fub.bytecode.Constants;
import de.fub.bytecode.Repository;
import de.fub.bytecode.classfile.JavaClass;

/** 
 * Super class for objects and arrays.
 *
 * @version $Id: ReferenceType.java,v 1.11 2001/08/21 17:44:13 ehaase Exp $
 * @author  <A HREF="http://www.berlin.de/~markus.dahm/">M. Dahm</A>
 */
public class ReferenceType extends Type {
  protected ReferenceType(byte t, String s) {
    super(t, s);
  }

  /** Class is non-abstract but not instantiable from the outside
   */
  ReferenceType() {
    super(Constants.T_OBJECT, "<null object>");
  }

  /**
   * Return true iff this type is castable to another type t as defined in
   * the JVM specification.  The case where this is Type.NULL is not
   * defined (see the CHECKCAST definition in the JVM specification).
   * However, because e.g. CHECKCAST doesn't throw a
   * ClassCastException when casting a null reference to any Object,
   * true is returned in this case.
   */
  public boolean isCastableTo(Type t){
    if(this.equals(Type.NULL))
      return true;		// If this is ever changed in isAssignmentCompatible()

    return isAssignmentCompatibleWith(t); /* Yes, it's true: It's the same definition.
					   * See vmspec2 AASTORE / CHECKCAST definitions.
					   */
  }

  /**
   * Return true iff this is assignment compatible with another type t
   * as defined in the JVM specification; see the AASTORE definition
   * there.
   */
  public boolean isAssignmentCompatibleWith(Type t) {
    if(!(t instanceof ReferenceType))
      return false;

    ReferenceType T = (ReferenceType)t;

    if(this.equals(Type.NULL))
      return true; // This is not explicitely stated, but clear. Isn't it?

    /* If this is a class type then
     */
    if((this instanceof ObjectType) && (((ObjectType) this).referencesClass())) {
      /* If T is a class type, then this must be the same class as T,
         or this must be a subclass of T;
      */
      if((T instanceof ObjectType) && (((ObjectType) T).referencesClass())) {
	if(this.equals(T))
	  return true;

	if(Repository.instanceOf( ((ObjectType) this).getClassName(),
				  ((ObjectType) T).getClassName()))
	  return true;
      }

      /* If T is an interface type, this must implement interface T.
       */
      if ((T instanceof ObjectType) && (((ObjectType) T).referencesInterface())) {
	if (Repository.implementationOf( ((ObjectType) this).getClassName(),
					 ((ObjectType) T).getClassName() ))
	  return true;
      }
    }

    /* If this is an interface type, then:
     */
    if ((this instanceof ObjectType) && (((ObjectType) this).referencesInterface())){
      /* If T is a class type, then T must be Object (