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 represents an entry in the provides table of the Module attribute.
028 * Each entry describes a service implementation that the parent module provides.
029 *
030 * @see   Module
031 * @since 6.4.0
032 */
033public final class ModuleProvides implements Cloneable, Node {
034
035    private final int provides_index;  // points to CONSTANT_Class_info
036    private final int provides_with_count;
037    private final int[] provides_with_index;  // points to CONSTANT_Class_info
038
039
040    /**
041     * Construct object from file stream.
042     *
043     * @param file Input stream
044     * @throws IOException if an I/O Exception occurs in readUnsignedShort
045     */
046    ModuleProvides(final DataInput file) throws IOException {
047        provides_index = file.readUnsignedShort();
048        provides_with_count = file.readUnsignedShort();
049        provides_with_index = new int[provides_with_count];
050        for (int i = 0; i < provides_with_count; i++) {
051            provides_with_index[i] = file.readUnsignedShort();
052        }
053    }
054
055
056    /**
057     * Called by objects that are traversing the nodes of the tree implicitely
058     * defined by the contents of a Java class. I.e., the hierarchy of methods,
059     * fields, attributes, etc. spawns a tree of objects.
060     *
061     * @param v Visitor object
062     */
063    @Override
064    public void accept( final Visitor v ) {
065        v.visitModuleProvides(this);
066    }
067
068    // TODO add more getters and setters?
069
070    /**
071     * Dump table entry to file stream in binary format.
072     *
073     * @param file Output file stream
074     * @throws IOException if an I/O Exception occurs in writeShort
075     */
076    public void dump( final DataOutputStream file ) throws IOException {
077        file.writeShort(provides_index);
078        file.writeShort(provides_with_count);
079        for (final int entry : provides_with_index) {
080            file.writeShort(entry);
081        }
082    }
083
084
085    /**
086     * @return String representation
087     */
088    @Override
089    public String toString() {
090        return "provides(" + provides_index + ", " + provides_with_count + ", ...)";
091    }
092
093
094    /**
095     * @return Resolved string representation
096     */
097    public String toString( final ConstantPool constant_pool ) {
098        final StringBuilder buf = new StringBuilder();
099        final String interface_name = constant_pool.constantToString(provides_index, Const.CONSTANT_Class);
100        buf.append(Utility.compactClassName(interface_name, false));
101        buf.append(", with(").append(provides_with_count).append("):\n");
102        for (final int index : provides_with_index) {
103            final String class_name = constant_pool.getConstantString(index, Const.CONSTANT_Class);
104            buf.append("      ").append(Utility.compactClassName(class_name, false)).append("\n");
105        }
106        return buf.substring(0, buf.length()-1); // remove the last newline
107    }
108
109
110    /**
111     * @return deep copy of this object
112     */
113    public ModuleProvides copy() {
114        try {
115            return (ModuleProvides) clone();
116        } catch (final CloneNotSupportedException e) {
117            // TODO should this throw?
118        }
119        return null;
120    }
121}