/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package org.apache.commons.compress.harmony.unpack200.bytecode;

import java.io.DataOutputStream;
import java.io.IOException;

/**
 * The abstract superclass for all types of class file entries.
 */
public abstract class ClassFileEntry {

    protected static final ClassFileEntry[] NONE = {};
    private boolean resolved;

    protected abstract void doWrite(DataOutputStream dos) throws IOException;

    @Override
    public abstract boolean equals(Object arg0);

    protected ClassFileEntry[] getNestedClassFileEntries() {
        return NONE;
    }

    @Override
    public abstract int hashCode();

    /**
     * Allows the constant pool entries to resolve their nested entries.
     *
     * @param pool TODO
     */
    protected void resolve(final ClassConstantPool pool) {
        resolved = true;
    }

    protected int objectHashCode() {
        return super.hashCode();
    }

    @Override
    public abstract String toString();

    public final void write(final DataOutputStream dos) throws IOException {
        if (!resolved) {
            throw new IllegalStateException("Entry has not been resolved");
        }
        doWrite(dos);
    }

}
