    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;
    023import java.util.Iterator;
    024import java.util.stream.Stream;
    025
    026import org.apache.bcel.Const;
    027
    028/**
    029 * This class represents a BootstrapMethods attribute.
    030 *
    031 * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.7.23"> The class File Format :
    032 *      The BootstrapMethods Attribute</a>
    033 * @since 6.0
    034 */
    035public class BootstrapMethods extends Attribute implements Iterable<BootstrapMethod> {
    036
    037    private BootstrapMethod[] bootstrapMethods; // TODO this could be made final (setter is not used)
    038
    039    /**
    040     * Initialize from another object. Note that both objects use the same references (shallow copy). Use clone() for a
    041     * physical copy.
    042     */
    043    public BootstrapMethods(final BootstrapMethods c) {
    044        this(c.getNameIndex(), c.getLength(), c.getBootstrapMethods(), c.getConstantPool());
    045    }
    046
    047    /**
    048     * @param nameIndex Index in constant pool to CONSTANT_Utf8
    049     * @param length Content length in bytes
    050     * @param bootstrapMethods array of bootstrap methods
    051     * @param constantPool Array of constants
    052     */
    053    public BootstrapMethods(final int nameIndex, final int length, final BootstrapMethod[] bootstrapMethods, final ConstantPool constantPool) {
    054        super(Const.ATTR_BOOTSTRAP_METHODS, nameIndex, length, constantPool);
    055        this.bootstrapMethods = bootstrapMethods;
    056    }
    057
    058    /**
    059     * Construct object from Input stream.
    060     *
    061     * @param nameIndex Index in constant pool to CONSTANT_Utf8
    062     * @param length Content length in bytes
    063     * @param input Input stream
    064     * @param constantPool Array of constants
    065     * @throws IOException if an I/O error occurs.
    066     */
    067    BootstrapMethods(final int nameIndex, final int length, final DataInput input, final ConstantPool constantPool) throws IOException {
    068        this(nameIndex, length, (BootstrapMethod[]) null, constantPool);
    069
    070        final int numBootstrapMethods = input.readUnsignedShort();
    071        bootstrapMethods = new BootstrapMethod[numBootstrapMethods];
    072        for (int i = 0; i < numBootstrapMethods; i++) {
    073            bootstrapMethods[i] = new BootstrapMethod(input);
    074        }
    075    }
    076
    077    /**
    078     * @param v Visitor object
    079     */
    080    @Override
    081    public void accept(final Visitor v) {
    082        v.visitBootstrapMethods(this);
    083    }
    084
    085    /**
    086     * @return deep copy of this attribute
    087     */
    088    @Override
    089    public BootstrapMethods copy(final ConstantPool constantPool) {
    090        final BootstrapMethods c = (BootstrapMethods) clone();
    091        c.bootstrapMethods = new BootstrapMethod[bootstrapMethods.length];
    092
    093        for (int i = 0; i < bootstrapMethods.length; i++) {
    094            c.bootstrapMethods[i] = bootstrapMethods[i].copy();
    095        }
    096        c.setConstantPool(constantPool);
    097        return c;
    098    }
    099
    100    /**
    101     * Dump bootstrap methods attribute to file stream in binary format.
    102     *
    103     * @param file Output file stream
    104     * @throws IOException if an I/O error occurs.
    105     */
    106    @Override
    107    public final void dump(final DataOutputStream file) throws IOException {
    108        super.dump(file);
    109
    110        file.writeShort(bootstrapMethods.length);
    111        for (final BootstrapMethod bootstrapMethod : bootstrapMethods) {
    112            bootstrapMethod.dump(file);
    113        }
    114    }
    115
    116    /**
    117     * @return array of bootstrap method "records"
    118     */
    119    public final BootstrapMethod[] getBootstrapMethods() {
    120        return bootstrapMethods;
    121    }
    122
    123    @Override
    124    public Iterator<BootstrapMethod> iterator() {
    125        return Stream.of(bootstrapMethods).iterator();
    126    }
    127
    128    /**
    129     * @param bootstrapMethods the array of bootstrap methods
    130     */
    131    public final void setBootstrapMethods(final BootstrapMethod[] bootstrapMethods) {
    132        this.bootstrapMethods = bootstrapMethods;
    133    }
    134
    135    /**
    136     * @return String representation.
    137     */
    138    @Override
    139    public final String toString() {
    140        final StringBuilder buf = new StringBuilder();
    141        buf.append("BootstrapMethods(");
    142        buf.append(bootstrapMethods.length);
    143        buf.append("):");
    144        for (int i = 0; i < bootstrapMethods.length; i++) {
    145            buf.append("\n");
    146            final int start = buf.length();
    147            buf.append("  ").append(i).append(": ");
    148            final int indentCount = buf.length() - start;
    149            final String[] lines = bootstrapMethods[i].toString(super.getConstantPool()).split("\\r?\\n");
    150            buf.append(lines[0]);
    151            for (int j = 1; j < lines.length; j++) {
    152                buf.append("\n").append("          ", 0, indentCount).append(lines[j]);
    153            }
    154        }
    155        return buf.toString();
    156    }
    157}