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 */
017package org.apache.bcel.generic;
018
019import org.apache.bcel.Const;
020
021/**
022 * Denotes array type, such as int[][]
023 */
024public final class ArrayType extends ReferenceType {
025
026    private final int dimensions;
027    private final Type basicType;
028
029    /**
030     * Convenience constructor for array type, e.g. int[]
031     *
032     * @param type array type, e.g. T_INT
033     */
034    public ArrayType(final byte type, final int dimensions) {
035        this(BasicType.getType(type), dimensions);
036    }
037
038    /**
039     * Convenience constructor for reference array type, e.g. Object[]
040     *
041     * @param className complete name of class (java.lang.String, e.g.)
042     */
043    public ArrayType(final String className, final int dimensions) {
044        this(ObjectType.getInstance(className), dimensions);
045    }
046
047    /**
048     * Constructor for array of given type
049     *
050     * @param type type of array (may be an array itself)
051     */
052    public ArrayType(final Type type, final int dimensions) {
053        super(Const.T_ARRAY, "<dummy>");
054        if (dimensions < 1 || dimensions > Const.MAX_BYTE) {
055            throw new ClassGenException("Invalid number of dimensions: " + dimensions);
056        }
057        switch (type.getType()) {
058        case Const.T_ARRAY:
059            final ArrayType array = (ArrayType) type;
060            this.dimensions = dimensions + array.dimensions;
061            basicType = array.basicType;
062            break;
063        case Const.T_VOID:
064            throw new ClassGenException("Invalid type: void[]");
065        default: // Basic type or reference
066            this.dimensions = dimensions;
067            basicType = type;
068            break;
069        }
070        final StringBuilder buf = new StringBuilder();
071        for (int i = 0; i < this.dimensions; i++) {
072            buf.append('[');
073        }
074        buf.append(basicType.getSignature());
075        super.setSignature(buf.toString());
076    }
077
078    /**
079     * @return true if both type objects refer to the same array type.
080     */
081    @Override
082    public boolean equals(final Object type) {
083        if (type instanceof ArrayType) {
084            final ArrayType array = (ArrayType) type;
085            return array.dimensions == dimensions && array.basicType.equals(basicType);
086        }
087        return false;
088    }
089
090    /**
091     * @return basic type of array, i.e., for int[][][] the basic type is int
092     */
093    public Type getBasicType() {
094        return basicType;
095    }
096
097    /**
098     * @return number of dimensions of array
099     */
100    public int getDimensions() {
101        return dimensions;
102    }
103
104    /**
105     * @return element type of array, i.e., for int[][][] the element type is int[][]
106     */
107    public Type getElementType() {
108        if (dimensions == 1) {
109            return basicType;
110        }
111        return new ArrayType(basicType, dimensions - 1);
112    }
113
114    /**
115     * @return a hash code value for the object.
116     */
117    @Override
118    public int hashCode() {
119        return basicType.hashCode() ^ dimensions;
120    }
121}