    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 */
    017package org.apache.commons.compress.harmony.unpack200.bytecode;
    018
    019import java.io.DataOutputStream;
    020import java.io.IOException;
    021
    022/**
    023 * The abstract superclass for all types of class file entries.
    024 */
    025public abstract class ClassFileEntry {
    026
    027    protected static final ClassFileEntry[] NONE = {};
    028    private boolean resolved;
    029
    030    protected abstract void doWrite(DataOutputStream dos) throws IOException;
    031
    032    @Override
    033    public abstract boolean equals(Object arg0);
    034
    035    protected ClassFileEntry[] getNestedClassFileEntries() {
    036        return NONE;
    037    }
    038
    039    @Override
    040    public abstract int hashCode();
    041
    042    /**
    043     * Allows the constant pool entries to resolve their nested entries.
    044     *
    045     * @param pool TODO
    046     */
    047    protected void resolve(final ClassConstantPool pool) {
    048        resolved = true;
    049    }
    050
    051    protected int objectHashCode() {
    052        return super.hashCode();
    053    }
    054
    055    @Override
    056    public abstract String toString();
    057
    058    public final void write(final DataOutputStream dos) throws IOException {
    059        if (!resolved) {
    060            throw new IllegalStateException("Entry has not been resolved");
    061        }
    062        doWrite(dos);
    063    }
    064
    065}