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1   /*
2    *  Licensed to the Apache Software Foundation (ASF) under one or more
3    *  contributor license agreements.  See the NOTICE file distributed with
4    *  this work for additional information regarding copyright ownership.
5    *  The ASF licenses this file to You under the Apache License, Version 2.0
6    *  (the "License"); you may not use this file except in compliance with
7    *  the License.  You may obtain a copy of the License at
8    *
9    *     http://www.apache.org/licenses/LICENSE-2.0
10   *
11   *  Unless required by applicable law or agreed to in writing, software
12   *  distributed under the License is distributed on an "AS IS" BASIS,
13   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   *  See the License for the specific language governing permissions and
15   *  limitations under the License.
16   */
17  package org.apache.commons.compress.harmony.unpack200.bytecode;
18  
19  import java.io.DataOutputStream;
20  import java.io.IOException;
21  
22  /**
23   * The abstract superclass for all types of class file entries.
24   */
25  public abstract class ClassFileEntry {
26  
27      protected static final ClassFileEntry[] NONE = {};
28      private boolean resolved;
29  
30      protected abstract void doWrite(DataOutputStream dos) throws IOException;
31  
32      @Override
33      public abstract boolean equals(Object arg0);
34  
35      protected ClassFileEntry[] getNestedClassFileEntries() {
36          return NONE;
37      }
38  
39      @Override
40      public abstract int hashCode();
41  
42      protected int objectHashCode() {
43          return super.hashCode();
44      }
45  
46      /**
47       * Allows the constant pool entries to resolve their nested entries.
48       *
49       * @param pool TODO
50       */
51      protected void resolve(final ClassConstantPool pool) {
52          resolved = true;
53      }
54  
55      @Override
56      public abstract String toString();
57  
58      public final void write(final DataOutputStream dos) throws IOException {
59          if (!resolved) {
60              throw new IllegalStateException("Entry has not been resolved");
61          }
62          doWrite(dos);
63      }
64  
65  }