    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one
    003 * or more contributor license agreements.  See the NOTICE file
    004 * distributed with this work for additional information
    005 * regarding copyright ownership.  The ASF licenses this file
    006 * to you under the Apache License, Version 2.0 (the
    007 * "License"); you may not use this file except in compliance
    008 * with the License.  You may obtain a copy of the License at
    009 *
    010 *   https://www.apache.org/licenses/LICENSE-2.0
    011 *
    012 * Unless required by applicable law or agreed to in writing,
    013 * software distributed under the License is distributed on an
    014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    015 * KIND, either express or implied.  See the License for the
    016 * specific language governing permissions and limitations
    017 * under the License.
    018 */
    019
    020package org.apache.bcel.classfile;
    021
    022import java.io.DataInput;
    023import java.io.DataOutputStream;
    024import java.io.IOException;
    025import java.util.Iterator;
    026import java.util.stream.Stream;
    027
    028import org.apache.bcel.Const;
    029
    030/**
    031 * This class represents a BootstrapMethods attribute.
    032 *
    033 * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.7.23"> The class File Format :
    034 *      The BootstrapMethods Attribute</a>
    035 * @since 6.0
    036 */
    037public class BootstrapMethods extends Attribute implements Iterable<BootstrapMethod> {
    038
    039    private BootstrapMethod[] bootstrapMethods; // TODO this could be made final (setter is not used)
    040
    041    /**
    042     * Initialize from another object. Note that both objects use the same references (shallow copy). Use clone() for a
    043     * physical copy.
    044     *
    045     * @param c Source to copy.
    046     */
    047    public BootstrapMethods(final BootstrapMethods c) {
    048        this(c.getNameIndex(), c.getLength(), c.getBootstrapMethods(), c.getConstantPool());
    049    }
    050
    051    /**
    052     * Constructs a BootstrapMethods attribute.
    053     *
    054     * @param nameIndex Index in constant pool to CONSTANT_Utf8.
    055     * @param length Content length in bytes.
    056     * @param bootstrapMethods array of bootstrap methods.
    057     * @param constantPool Array of constants.
    058     */
    059    public BootstrapMethods(final int nameIndex, final int length, final BootstrapMethod[] bootstrapMethods, final ConstantPool constantPool) {
    060        super(Const.ATTR_BOOTSTRAP_METHODS, nameIndex, length, constantPool);
    061        setBootstrapMethods(bootstrapMethods);
    062    }
    063
    064    /**
    065     * Constructs object from Input stream.
    066     *
    067     * @param nameIndex Index in constant pool to CONSTANT_Utf8.
    068     * @param length Content length in bytes.
    069     * @param input Input stream.
    070     * @param constantPool Array of constants.
    071     * @throws IOException if an I/O error occurs.
    072     */
    073    BootstrapMethods(final int nameIndex, final int length, final DataInput input, final ConstantPool constantPool) throws IOException {
    074        this(nameIndex, length, (BootstrapMethod[]) null, constantPool);
    075
    076        final int numBootstrapMethods = input.readUnsignedShort();
    077        bootstrapMethods = new BootstrapMethod[numBootstrapMethods];
    078        for (int i = 0; i < numBootstrapMethods; i++) {
    079            bootstrapMethods[i] = new BootstrapMethod(input);
    080        }
    081    }
    082
    083    /**
    084     * Accepts a visitor.
    085     *
    086     * @param v Visitor object.
    087     */
    088    @Override
    089    public void accept(final Visitor v) {
    090        v.visitBootstrapMethods(this);
    091    }
    092
    093    /**
    094     * Creates a deep copy of this attribute.
    095     *
    096     * @param constantPool the constant pool.
    097     * @return deep copy of this attribute.
    098     */
    099    @Override
    100    public BootstrapMethods copy(final ConstantPool constantPool) {
    101        final BootstrapMethods c = (BootstrapMethods) clone();
    102        c.bootstrapMethods = new BootstrapMethod[bootstrapMethods.length];
    103
    104        for (int i = 0; i < bootstrapMethods.length; i++) {
    105            c.bootstrapMethods[i] = bootstrapMethods[i].copy();
    106        }
    107        c.setConstantPool(constantPool);
    108        return c;
    109    }
    110
    111    /**
    112     * Dumps bootstrap methods attribute to file stream in binary format.
    113     *
    114     * @param file Output file stream.
    115     * @throws IOException if an I/O error occurs.
    116     */
    117    @Override
    118    public final void dump(final DataOutputStream file) throws IOException {
    119        super.dump(file);
    120
    121        file.writeShort(bootstrapMethods.length);
    122        for (final BootstrapMethod bootstrapMethod : bootstrapMethods) {
    123            bootstrapMethod.dump(file);
    124        }
    125    }
    126
    127    /**
    128     * Gets the array of bootstrap method records.
    129     *
    130     * @return array of bootstrap method records.
    131     */
    132    public final BootstrapMethod[] getBootstrapMethods() {
    133        return bootstrapMethods;
    134    }
    135
    136    @Override
    137    public Iterator<BootstrapMethod> iterator() {
    138        return Stream.of(bootstrapMethods).iterator();
    139    }
    140
    141    /**
    142     * Sets the bootstrap methods.
    143     *
    144     * @param bootstrapMethods the array of bootstrap methods.
    145     */
    146    public final void setBootstrapMethods(final BootstrapMethod[] bootstrapMethods) {
    147        this.bootstrapMethods = bootstrapMethods != null ? bootstrapMethods : BootstrapMethod.EMPTY_ARRAY;
    148    }
    149
    150    /**
    151     * @return String representation.
    152     */
    153    @Override
    154    public final String toString() {
    155        final StringBuilder buf = new StringBuilder();
    156        buf.append("BootstrapMethods(");
    157        buf.append(bootstrapMethods.length);
    158        buf.append("):");
    159        for (int i = 0; i < bootstrapMethods.length; i++) {
    160            buf.append("\n");
    161            final int start = buf.length();
    162            buf.append("  ").append(i).append(": ");
    163            final int indentCount = buf.length() - start;
    164            final String[] lines = bootstrapMethods[i].toString(super.getConstantPool()).split("\\r?\\n");
    165            buf.append(lines[0]);
    166            for (int j = 1; j < lines.length; j++) {
    167                buf.append("\n").append("          ", 0, indentCount).append(lines[j]);
    168            }
    169        }
    170        return buf.toString();
    171    }
    172}