    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     * @param c Source to copy.
    044     */
    045    public BootstrapMethods(final BootstrapMethods c) {
    046        this(c.getNameIndex(), c.getLength(), c.getBootstrapMethods(), c.getConstantPool());
    047    }
    048
    049    /**
    050     * @param nameIndex Index in constant pool to CONSTANT_Utf8
    051     * @param length Content length in bytes
    052     * @param bootstrapMethods array of bootstrap methods
    053     * @param constantPool Array of constants
    054     */
    055    public BootstrapMethods(final int nameIndex, final int length, final BootstrapMethod[] bootstrapMethods, final ConstantPool constantPool) {
    056        super(Const.ATTR_BOOTSTRAP_METHODS, nameIndex, length, constantPool);
    057        setBootstrapMethods(bootstrapMethods);
    058    }
    059
    060    /**
    061     * Constructs object from Input stream.
    062     *
    063     * @param nameIndex Index in constant pool to CONSTANT_Utf8
    064     * @param length Content length in bytes
    065     * @param input Input stream
    066     * @param constantPool Array of constants
    067     * @throws IOException if an I/O error occurs.
    068     */
    069    BootstrapMethods(final int nameIndex, final int length, final DataInput input, final ConstantPool constantPool) throws IOException {
    070        this(nameIndex, length, (BootstrapMethod[]) null, constantPool);
    071
    072        final int numBootstrapMethods = input.readUnsignedShort();
    073        bootstrapMethods = new BootstrapMethod[numBootstrapMethods];
    074        for (int i = 0; i < numBootstrapMethods; i++) {
    075            bootstrapMethods[i] = new BootstrapMethod(input);
    076        }
    077    }
    078
    079    /**
    080     * @param v Visitor object
    081     */
    082    @Override
    083    public void accept(final Visitor v) {
    084        v.visitBootstrapMethods(this);
    085    }
    086
    087    /**
    088     * @return deep copy of this attribute
    089     */
    090    @Override
    091    public BootstrapMethods copy(final ConstantPool constantPool) {
    092        final BootstrapMethods c = (BootstrapMethods) clone();
    093        c.bootstrapMethods = new BootstrapMethod[bootstrapMethods.length];
    094
    095        for (int i = 0; i < bootstrapMethods.length; i++) {
    096            c.bootstrapMethods[i] = bootstrapMethods[i].copy();
    097        }
    098        c.setConstantPool(constantPool);
    099        return c;
    100    }
    101
    102    /**
    103     * Dump bootstrap methods attribute to file stream in binary format.
    104     *
    105     * @param file Output file stream
    106     * @throws IOException if an I/O error occurs.
    107     */
    108    @Override
    109    public final void dump(final DataOutputStream file) throws IOException {
    110        super.dump(file);
    111
    112        file.writeShort(bootstrapMethods.length);
    113        for (final BootstrapMethod bootstrapMethod : bootstrapMethods) {
    114            bootstrapMethod.dump(file);
    115        }
    116    }
    117
    118    /**
    119     * @return array of bootstrap method "records"
    120     */
    121    public final BootstrapMethod[] getBootstrapMethods() {
    122        return bootstrapMethods;
    123    }
    124
    125    @Override
    126    public Iterator<BootstrapMethod> iterator() {
    127        return Stream.of(bootstrapMethods).iterator();
    128    }
    129
    130    /**
    131     * @param bootstrapMethods the array of bootstrap methods
    132     */
    133    public final void setBootstrapMethods(final BootstrapMethod[] bootstrapMethods) {
    134        this.bootstrapMethods = bootstrapMethods != null ? bootstrapMethods : BootstrapMethod.EMPTY_ARRAY;
    135    }
    136
    137    /**
    138     * @return String representation.
    139     */
    140    @Override
    141    public final String toString() {
    142        final StringBuilder buf = new StringBuilder();
    143        buf.append("BootstrapMethods(");
    144        buf.append(bootstrapMethods.length);
    145        buf.append("):");
    146        for (int i = 0; i < bootstrapMethods.length; i++) {
    147            buf.append("\n");
    148            final int start = buf.length();
    149            buf.append("  ").append(i).append(": ");
    150            final int indentCount = buf.length() - start;
    151            final String[] lines = bootstrapMethods[i].toString(super.getConstantPool()).split("\\r?\\n");
    152            buf.append(lines[0]);
    153            for (int j = 1; j < lines.length; j++) {
    154                buf.append("\n").append("          ", 0, indentCount).append(lines[j]);
    155            }
    156        }
    157        return buf.toString();
    158    }
    159}