    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.classfile;
    019
    020import java.io.DataInput;
    021import java.io.DataOutputStream;
    022import java.io.IOException;
    023
    024import org.apache.bcel.Const;
    025
    026/**
    027 * This class is derived from <em>Attribute</em> and represents the list of modules required, exported, opened or provided by a module.
    028 * There may be at most one Module attribute in a ClassFile structure.
    029 *
    030 * @see   Attribute
    031 * @since 6.4.0
    032 */
    033public final class Module extends Attribute {
    034
    035    private final int module_name_index;
    036    private final int module_flags;
    037    private final int module_version_index;
    038
    039    private ModuleRequires[] requires_table;
    040    private ModuleExports[] exports_table;
    041    private ModuleOpens[] opens_table;
    042    private final int uses_count;
    043    private final int[] uses_index;
    044    private ModuleProvides[] provides_table;
    045
    046    /**
    047     * Construct object from input stream.
    048     * @param name_index Index in constant pool
    049     * @param length Content length in bytes
    050     * @param input Input stream
    051     * @param constant_pool Array of constants
    052     * @throws IOException
    053     */
    054    Module(final int name_index, final int length, final DataInput input, final ConstantPool constant_pool) throws IOException {
    055        super(Const.ATTR_MODULE, name_index, length, constant_pool);
    056
    057        module_name_index = input.readUnsignedShort();
    058        module_flags = input.readUnsignedShort();
    059        module_version_index = input.readUnsignedShort();
    060
    061        final int requires_count = input.readUnsignedShort();
    062        requires_table = new ModuleRequires[requires_count];
    063        for (int i = 0; i < requires_count; i++) {
    064            requires_table[i] = new ModuleRequires(input);
    065        }
    066
    067        final int exports_count = input.readUnsignedShort();
    068        exports_table = new ModuleExports[exports_count];
    069        for (int i = 0; i < exports_count; i++) {
    070            exports_table[i] = new ModuleExports(input);
    071        }
    072
    073        final int opens_count = input.readUnsignedShort();
    074        opens_table = new ModuleOpens[opens_count];
    075        for (int i = 0; i < opens_count; i++) {
    076            opens_table[i] = new ModuleOpens(input);
    077        }
    078
    079        uses_count = input.readUnsignedShort();
    080        uses_index = new int[uses_count];
    081        for (int i = 0; i < uses_count; i++) {
    082            uses_index[i] = input.readUnsignedShort();
    083        }
    084
    085        final int provides_count = input.readUnsignedShort();
    086        provides_table = new ModuleProvides[provides_count];
    087        for (int i = 0; i < provides_count; i++) {
    088            provides_table[i] = new ModuleProvides(input);
    089        }
    090    }
    091
    092
    093    /**
    094     * Called by objects that are traversing the nodes of the tree implicitely
    095     * defined by the contents of a Java class. I.e., the hierarchy of methods,
    096     * fields, attributes, etc. spawns a tree of objects.
    097     *
    098     * @param v Visitor object
    099     */
    100    @Override
    101    public void accept( final Visitor v ) {
    102        v.visitModule(this);
    103    }
    104
    105    // TODO add more getters and setters?
    106
    107    /**
    108     * @return table of required modules
    109     * @see ModuleRequires
    110     */
    111    public ModuleRequires[] getRequiresTable() {
    112        return requires_table;
    113    }
    114
    115
    116    /**
    117     * @return table of exported interfaces
    118     * @see ModuleExports
    119     */
    120    public ModuleExports[] getExportsTable() {
    121        return exports_table;
    122    }
    123
    124
    125    /**
    126     * @return table of provided interfaces
    127     * @see ModuleOpens
    128     */
    129    public ModuleOpens[] getOpensTable() {
    130        return opens_table;
    131    }
    132
    133
    134    /**
    135     * @return table of provided interfaces
    136     * @see ModuleProvides
    137     */
    138    public ModuleProvides[] getProvidesTable() {
    139        return provides_table;
    140    }
    141
    142
    143    /**
    144     * Dump Module attribute to file stream in binary format.
    145     *
    146     * @param file Output file stream
    147     * @throws IOException
    148     */
    149    @Override
    150    public void dump( final DataOutputStream file ) throws IOException {
    151        super.dump(file);
    152
    153        file.writeShort(module_name_index);
    154        file.writeShort(module_flags);
    155        file.writeShort(module_version_index);
    156
    157        file.writeShort(requires_table.length);
    158        for (final ModuleRequires entry : requires_table) {
    159            entry.dump(file);
    160        }
    161
    162        file.writeShort(exports_table.length);
    163        for (final ModuleExports entry : exports_table) {
    164            entry.dump(file);
    165        }
    166
    167        file.writeShort(opens_table.length);
    168        for (final ModuleOpens entry : opens_table) {
    169            entry.dump(file);
    170        }
    171
    172        file.writeShort(uses_index.length);
    173        for (final int entry : uses_index) {
    174            file.writeShort(entry);
    175        }
    176
    177        file.writeShort(provides_table.length);
    178        for (final ModuleProvides entry : provides_table) {
    179            entry.dump(file);
    180        }
    181    }
    182
    183
    184    /**
    185     * @return String representation, i.e., a list of packages.
    186     */
    187    @Override
    188    public String toString() {
    189        final ConstantPool cp = super.getConstantPool();
    190        final StringBuilder buf = new StringBuilder();
    191        buf.append("Module:\n");
    192        buf.append("  name:    ") .append(cp.getConstantString(module_name_index, Const.CONSTANT_Module).replace('/', '.')).append("\n");
    193        buf.append("  flags:   ") .append(String.format("%04x", module_flags)).append("\n");
    194        final String version = module_version_index == 0 ? "0" : cp.getConstantString(module_version_index, Const.CONSTANT_Utf8);
    195        buf.append("  version: ") .append(version).append("\n");
    196
    197        buf.append("  requires(").append(requires_table.length).append("):\n");
    198        for (final ModuleRequires module : requires_table) {
    199            buf.append("    ").append(module.toString(cp)).append("\n");
    200        }
    201
    202        buf.append("  exports(").append(exports_table.length).append("):\n");
    203        for (final ModuleExports module : exports_table) {
    204            buf.append("    ").append(module.toString(cp)).append("\n");
    205        }
    206
    207        buf.append("  opens(").append(opens_table.length).append("):\n");
    208        for (final ModuleOpens module : opens_table) {
    209            buf.append("    ").append(module.toString(cp)).append("\n");
    210        }
    211
    212        buf.append("  uses(").append(uses_index.length).append("):\n");
    213        for (final int index : uses_index) {
    214            final String class_name = cp.getConstantString(index, Const.CONSTANT_Class);
    215            buf.append("    ").append(Utility.compactClassName(class_name, false)).append("\n");
    216        }
    217
    218        buf.append("  provides(").append(provides_table.length).append("):\n");
    219        for (final ModuleProvides module : provides_table) {
    220            buf.append("    ").append(module.toString(cp)).append("\n");
    221        }
    222
    223        return buf.substring(0, buf.length()-1); // remove the last newline
    224    }
    225
    226
    227    /**
    228     * @return deep copy of this attribute
    229     */
    230    @Override
    231    public Attribute copy( final ConstantPool _constant_pool ) {
    232        final Module c = (Module) clone();
    233
    234        c.requires_table = new ModuleRequires[requires_table.length];
    235        for (int i = 0; i < requires_table.length; i++) {
    236            c.requires_table[i] = requires_table[i].copy();
    237        }
    238
    239        c.exports_table = new ModuleExports[exports_table.length];
    240        for (int i = 0; i < exports_table.length; i++) {
    241            c.exports_table[i] = exports_table[i].copy();
    242        }
    243
    244        c.opens_table = new ModuleOpens[opens_table.length];
    245        for (int i = 0; i < opens_table.length; i++) {
    246            c.opens_table[i] = opens_table[i].copy();
    247        }
    248
    249        c.provides_table = new ModuleProvides[provides_table.length];
    250        for (int i = 0; i < provides_table.length; i++) {
    251            c.provides_table[i] = provides_table[i].copy();
    252        }
    253
    254        c.setConstantPool(_constant_pool);
    255        return c;
    256    }
    257}