fieldormethod.java

该开源工具主要用于class文件的操作

package org.apache.bcel.generic;

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2001 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" and
 *    "Apache BCEL" must not be used to endorse or promote products
 *    derived from this software without prior written permission. For
 *    written permission, please contact [e-mail].
 *
 * 5. Products derived from this software may not be called "Apache",
 *    "Apache BCEL", nor may "Apache" appear in their name, without
 *    prior written permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */
import org.apache.bcel.classfile.*;

/**
 * Super class for InvokeInstruction and FieldInstruction, since they have
 * some methods in common!
 *
 * @version $Id: FieldOrMethod.java,v 1.1.1.1 2001/10/29 20:00:13 jvanzyl Exp $
 * @author  <A HREF="mailto:[e-mail]">M. Dahm</A>
 */
public abstract class FieldOrMethod extends CPInstruction implements LoadClass {
  /**
   * Empty constructor needed for the Class.newInstance() statement in
   * Instruction.readInstruction(). Not to be used otherwise.
   */
  FieldOrMethod() {}

  /**
   * @param index to constant pool
   */
  protected FieldOrMethod(short opcode, int index) {
    super(opcode, index);
  }

  /** @return signature of referenced method/field.
   */
  public String getSignature(ConstantPoolGen cpg) {
    ConstantPool        cp   = cpg.getConstantPool();
    ConstantCP          cmr  = (ConstantCP)cp.getConstant(index);
    ConstantNameAndType cnat = (ConstantNameAndType)cp.getConstant(cmr.getNameAndTypeIndex());

    return ((ConstantUtf8)cp.getConstant(cnat.getSignatureIndex())).getBytes();
  }

  /** @return name of referenced method/field.
   */
  public String getName(ConstantPoolGen cpg) {
    ConstantPool        cp   = cpg.getConstantPool();
    ConstantCP          cmr  = (ConstantCP)cp.getConstant(index);
    ConstantNameAndType cnat = (ConstantNameAndType)cp.getConstant(cmr.getNameAndTypeIndex());
    return ((ConstantUtf8)cp.getConstant(cnat.getNameIndex())).getBytes();
  }

  /** @return name of the referenced class/interface
   */
  public String getClassName(ConstantPoolGen cpg) {
    ConstantPool cp  = cpg.getConstantPool();
    ConstantCP   cmr = (ConstantCP)cp.getConstant(index);
    return cp.getConstantString(cmr.getClassIndex(), org.apache.bcel.Constants.CONSTANT_Class).replace('/', '.');
  }

  /** @return type of the referenced class/interface
   */
  public ObjectType getClassType(ConstantPoolGen cpg) {
    return new ObjectType(getClassName(cpg));
  }

  /** @return type of the referenced class/interface
   */
  public ObjectType getLoadClassType(ConstantPoolGen cpg) {
    return getClassType(cpg);
  }
}