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.generic;
019
020import org.apache.bcel.Const;
021
022/**
023 * Denotes array type, such as int[][]
024 *
025 */
026public final class ArrayType extends ReferenceType {
027
028    private int dimensions;
029    private Type basic_type;
030
031
032    /**
033     * Convenience constructor for array type, e.g. int[]
034     *
035     * @param type array type, e.g. T_INT
036     */
037    public ArrayType(final byte type, final int dimensions) {
038        this(BasicType.getType(type), dimensions);
039    }
040
041
042    /**
043     * Convenience constructor for reference array type, e.g. Object[]
044     *
045     * @param class_name complete name of class (java.lang.String, e.g.)
046     */
047    public ArrayType(final String class_name, final int dimensions) {
048        this(ObjectType.getInstance(class_name), dimensions);
049    }
050
051
052    /**
053     * Constructor for array of given type
054     *
055     * @param type type of array (may be an array itself)
056     */
057    public ArrayType(final Type type, final int dimensions) {
058        super(Const.T_ARRAY, "<dummy>");
059        if ((dimensions < 1) || (dimensions > Const.MAX_BYTE)) {
060            throw new ClassGenException("Invalid number of dimensions: " + dimensions);
061        }
062        switch (type.getType()) {
063            case Const.T_ARRAY:
064                final ArrayType array = (ArrayType) type;
065                this.dimensions = dimensions + array.dimensions;
066                basic_type = array.basic_type;
067                break;
068            case Const.T_VOID:
069                throw new ClassGenException("Invalid type: void[]");
070            default: // Basic type or reference
071                this.dimensions = dimensions;
072                basic_type = type;
073                break;
074        }
075        final StringBuilder buf = new StringBuilder();
076        for (int i = 0; i < this.dimensions; i++) {
077            buf.append('[');
078        }
079        buf.append(basic_type.getSignature());
080        super.setSignature(buf.toString());
081    }
082
083
084    /**
085     * @return basic type of array, i.e., for int[][][] the basic type is int
086     */
087    public Type getBasicType() {
088        return basic_type;
089    }
090
091
092    /**
093     * @return element type of array, i.e., for int[][][] the element type is int[][]
094     */
095    public Type getElementType() {
096        if (dimensions == 1) {
097            return basic_type;
098        }
099        return new ArrayType(basic_type, dimensions - 1);
100    }
101
102
103    /** @return number of dimensions of array
104     */
105    public int getDimensions() {
106        return dimensions;
107    }
108
109
110    /** @return a hash code value for the object.
111     */
112    @Override
113    public int hashCode() {
114        return basic_type.hashCode() ^ dimensions;
115    }
116
117
118    /** @return true if both type objects refer to the same array type.
119     */
120    @Override
121    public boolean equals( final Object _type ) {
122        if (_type instanceof ArrayType) {
123            final ArrayType array = (ArrayType) _type;
124            return (array.dimensions == dimensions) && array.basic_type.equals(basic_type);
125        }
126        return false;
127    }
128}