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