    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.IOException;
    024
    025import org.apache.bcel.Const;
    026import org.apache.bcel.util.Args;
    027import org.apache.commons.lang3.ArrayUtils;
    028
    029/**
    030 * This class is derived from <em>Attribute</em> and denotes that this is a deprecated method. It is instantiated from the <em>Attribute.readAttribute()</em>
    031 * method.
    032 *
    033 * <pre>
    034 * Deprecated_attribute {
    035 *     u2 attribute_name_index;
    036 *     u4 attribute_length;
    037 * }
    038 * </pre>
    039 *
    040 * @see Attribute
    041 * @see <a href="https://docs.oracle.com/javase/specs/jvms/se25/html/jvms-4.html#jvms-4.7.15">JVM Specification: The Deprecated Attribute</a>
    042 */
    043public final class Deprecated extends Attribute {
    044
    045    /**
    046     * Initialize from another object. Note that both objects use the same references (shallow copy). Use clone() for a physical copy.
    047     *
    048     * @param c Source to copy.
    049     */
    050    public Deprecated(final Deprecated c) {
    051        this(c.getNameIndex(), c.getLength(), c.getBytes(), c.getConstantPool());
    052    }
    053
    054    /**
    055     * Constructs a Deprecated attribute.
    056     *
    057     * @param nameIndex    Index in constant pool to CONSTANT_Utf8.
    058     * @param length       JVM Specification: "The value of the attribute_length item must be zero.".
    059     * @param bytes        Attribute contents.
    060     * @param constantPool Array of constants.
    061     * @see <a href="https://docs.oracle.com/javase/specs/jvms/se25/html/jvms-4.html#jvms-4.7.15">JVM Specification: The Deprecated Attribute</a>
    062     */
    063    public Deprecated(final int nameIndex, final int length, final byte[] bytes, final ConstantPool constantPool) {
    064        super(Const.ATTR_DEPRECATED, nameIndex, Args.require0(length, "Deprecated attribute length"), constantPool);
    065    }
    066
    067    /**
    068     * Constructs object from input stream.
    069     *
    070     * @param nameIndex    Index in constant pool to CONSTANT_Utf8.
    071     * @param length       JVM Specification: "The value of the attribute_length item must be zero.".
    072     * @param input        Input stream.
    073     * @param constantPool Array of constants.
    074     * @throws IOException if an I/O error occurs.
    075     * @see <a href="https://docs.oracle.com/javase/specs/jvms/se25/html/jvms-4.html#jvms-4.7.15">JVM Specification: The Deprecated Attribute</a>
    076     */
    077    Deprecated(final int nameIndex, final int length, final DataInput input, final ConstantPool constantPool) throws IOException {
    078        this(nameIndex, length, (byte[]) null, constantPool);
    079    }
    080
    081    /**
    082     * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class. That is, the hierarchy of methods,
    083     * fields, attributes, etc. spawns a tree of objects.
    084     *
    085     * @param v Visitor object.
    086     */
    087    @Override
    088    public void accept(final Visitor v) {
    089        v.visitDeprecated(this);
    090    }
    091
    092    /**
    093     * @return deep copy of this attribute.
    094     */
    095    @Override
    096    public Attribute copy(final ConstantPool constantPool) {
    097        final Deprecated c = (Deprecated) clone();
    098        c.setConstantPool(constantPool);
    099        return c;
    100    }
    101
    102    /**
    103     * Gets the data bytes.
    104     *
    105     * @return data bytes.
    106     */
    107    public byte[] getBytes() {
    108        return ArrayUtils.EMPTY_BYTE_ARRAY;
    109    }
    110
    111    /**
    112     * Sets the data bytes.
    113     *
    114     * @param bytes the raw bytes that represents this byte array.
    115     */
    116    public void setBytes(final byte[] bytes) {
    117        if (bytes != null) {
    118            Args.require0(bytes.length, "Deprecated attribute length");
    119        }
    120    }
    121
    122    /**
    123     * @return attribute name.
    124     */
    125    @Override
    126    public String toString() {
    127        return Const.getAttributeName(Const.ATTR_DEPRECATED) + ": true";
    128    }
    129}