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
18 package org.apache.bcel.classfile;
19
20 import java.io.DataInput;
21 import java.io.DataOutputStream;
22 import java.io.IOException;
23
24 import org.apache.bcel.Const;
25
26 /**
27 * This class represents an entry in the requires table of the Module attribute. Each entry describes a module on which
28 * the parent module depends.
29 *
30 * @see Module
31 * @since 6.4.0
32 */
33 public final class ModuleRequires implements Cloneable, Node {
34
35 private final int requiresIndex; // points to CONSTANT_Module_info
36 private final int requiresFlags;
37 private final int requiresVersionIndex; // either 0 or points to CONSTANT_Utf8_info
38
39 /**
40 * Constructs object from file stream.
41 *
42 * @param file Input stream
43 * @throws IOException if an I/O Exception occurs in readUnsignedShort
44 */
45 ModuleRequires(final DataInput file) throws IOException {
46 requiresIndex = file.readUnsignedShort();
47 requiresFlags = file.readUnsignedShort();
48 requiresVersionIndex = file.readUnsignedShort();
49 }
50
51 /**
52 * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class.
53 * I.e., the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.
54 *
55 * @param v Visitor object
56 */
57 @Override
58 public void accept(final Visitor v) {
59 v.visitModuleRequires(this);
60 }
61
62 // TODO add more getters and setters?
63
64 /**
65 * @return deep copy of this object
66 */
67 public ModuleRequires copy() {
68 try {
69 return (ModuleRequires) clone();
70 } catch (final CloneNotSupportedException e) {
71 // TODO should this throw?
72 }
73 return null;
74 }
75
76 /**
77 * Dump table entry to file stream in binary format.
78 *
79 * @param file Output file stream
80 * @throws IOException if an I/O Exception occurs in writeShort
81 */
82 public void dump(final DataOutputStream file) throws IOException {
83 file.writeShort(requiresIndex);
84 file.writeShort(requiresFlags);
85 file.writeShort(requiresVersionIndex);
86 }
87
88 /**
89 * @return String representation
90 */
91 @Override
92 public String toString() {
93 return "requires(" + requiresIndex + ", " + String.format("%04x", requiresFlags) + ", " + requiresVersionIndex + ")";
94 }
95
96 /**
97 * @return Resolved string representation
98 */
99 public String toString(final ConstantPool constantPool) {
100 final StringBuilder buf = new StringBuilder();
101 final String moduleName = constantPool.constantToString(requiresIndex, Const.CONSTANT_Module);
102 buf.append(Utility.compactClassName(moduleName, false));
103 buf.append(", ").append(String.format("%04x", requiresFlags));
104 final String version = requiresVersionIndex == 0 ? "0" : constantPool.getConstantString(requiresVersionIndex, Const.CONSTANT_Utf8);
105 buf.append(", ").append(version);
106 return buf.toString();
107 }
108 }