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