    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 *  Unless required by applicable law or agreed to in writing, software
    012 *  distributed under the License is distributed on an "AS IS" BASIS,
    013 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 *  See the License for the specific language governing permissions and
    015 *  limitations under the License.
    016 *
    017 */
    018package org.apache.bcel.generic;
    019
    020import org.apache.bcel.Const;
    021import org.apache.bcel.classfile.ConstantCP;
    022import org.apache.bcel.classfile.ConstantNameAndType;
    023import org.apache.bcel.classfile.ConstantPool;
    024import org.apache.bcel.classfile.ConstantUtf8;
    025import org.apache.bcel.classfile.Utility;
    026
    027/**
    028 * Super class for InvokeInstruction and FieldInstruction, since they have some methods in common!
    029 *
    030 */
    031public abstract class FieldOrMethod extends CPInstruction implements LoadClass {
    032
    033    /**
    034     * Empty constructor needed for Instruction.readInstruction. Not to be used otherwise.
    035     */
    036    FieldOrMethod() {
    037        // no init
    038    }
    039
    040    /**
    041     * @param index to constant pool
    042     */
    043    protected FieldOrMethod(final short opcode, final int index) {
    044        super(opcode, index);
    045    }
    046
    047    /**
    048     * @return name of the referenced class/interface
    049     * @deprecated If the instruction references an array class, this method will return "java.lang.Object". For code
    050     *             generated by Java 1.5, this answer is sometimes wrong (e.g., if the "clone()" method is called on an
    051     *             array). A better idea is to use the {@link #getReferenceType(ConstantPoolGen)} method, which correctly
    052     *             distinguishes between class types and array types.
    053     *
    054     */
    055    @Deprecated
    056    public String getClassName(final ConstantPoolGen cpg) {
    057        final ConstantPool cp = cpg.getConstantPool();
    058        final ConstantCP cmr = (ConstantCP) cp.getConstant(super.getIndex());
    059        final String className = cp.getConstantString(cmr.getClassIndex(), Const.CONSTANT_Class);
    060        if (className.startsWith("[")) {
    061            // Turn array classes into java.lang.Object.
    062            return "java.lang.Object";
    063        }
    064        return Utility.pathToPackage(className);
    065    }
    066
    067    /**
    068     * @return type of the referenced class/interface
    069     * @deprecated If the instruction references an array class, the ObjectType returned will be invalid. Use
    070     *             getReferenceType() instead.
    071     */
    072    @Deprecated
    073    public ObjectType getClassType(final ConstantPoolGen cpg) {
    074        return ObjectType.getInstance(getClassName(cpg));
    075    }
    076
    077    /**
    078     * Gets the ObjectType of the method return or field.
    079     *
    080     * @return type of the referenced class/interface
    081     * @throws ClassGenException when the field is (or method returns) an array,
    082     */
    083    @Override
    084    public ObjectType getLoadClassType(final ConstantPoolGen cpg) {
    085        final ReferenceType rt = getReferenceType(cpg);
    086        if (rt instanceof ObjectType) {
    087            return (ObjectType) rt;
    088        }
    089        throw new ClassGenException(rt.getClass().getCanonicalName() + " " + rt.getSignature() + " does not represent an ObjectType");
    090    }
    091
    092    /**
    093     * @return name of referenced method/field.
    094     */
    095    public String getName(final ConstantPoolGen cpg) {
    096        final ConstantPool cp = cpg.getConstantPool();
    097        final ConstantCP cmr = (ConstantCP) cp.getConstant(super.getIndex());
    098        final ConstantNameAndType cnat = (ConstantNameAndType) cp.getConstant(cmr.getNameAndTypeIndex());
    099        return ((ConstantUtf8) cp.getConstant(cnat.getNameIndex())).getBytes();
    100    }
    101
    102    /**
    103     * Gets the reference type representing the class, interface, or array class referenced by the instruction.
    104     *
    105     * @param cpg the ConstantPoolGen used to create the instruction
    106     * @return an ObjectType (if the referenced class type is a class or interface), or an ArrayType (if the referenced
    107     *         class type is an array class)
    108     */
    109    public ReferenceType getReferenceType(final ConstantPoolGen cpg) {
    110        final ConstantPool cp = cpg.getConstantPool();
    111        final ConstantCP cmr = (ConstantCP) cp.getConstant(super.getIndex());
    112        String className = cp.getConstantString(cmr.getClassIndex(), Const.CONSTANT_Class);
    113        if (className.startsWith("[")) {
    114            return (ArrayType) Type.getType(className);
    115        }
    116        className = Utility.pathToPackage(className);
    117        return ObjectType.getInstance(className);
    118    }
    119
    120    /**
    121     * @return signature of referenced method/field.
    122     */
    123    public String getSignature(final ConstantPoolGen cpg) {
    124        final ConstantPool cp = cpg.getConstantPool();
    125        final ConstantCP cmr = (ConstantCP) cp.getConstant(super.getIndex());
    126        final ConstantNameAndType cnat = (ConstantNameAndType) cp.getConstant(cmr.getNameAndTypeIndex());
    127        return ((ConstantUtf8) cp.getConstant(cnat.getSignatureIndex())).getBytes();
    128    }
    129}