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/*

 * Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements.  See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You under the Apache License, Version 2.0

 * (the "License"); you may not use this file except in compliance with

 * the License.  You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 *  Unless required by applicable law or agreed to in writing, software

 *  distributed under the License is distributed on an "AS IS" BASIS,

 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 *  See the License for the specific language governing permissions and

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package com.sun.org.apache.bcel.internal.classfile;

import java.io.DataInput;

import java.io.DataOutputStream;

import java.io.IOException;

import com.sun.org.apache.bcel.internal.Const;

/**

 * This class is derived from <em>Attribute</em> and represents the list of packages that are exported or opened by the Module attribute.

 * There may be at most one ModulePackages attribute in a ClassFile structure.

 *

 * @see     Attribute

 */

public final class ModulePackages extends Attribute {

    private int[] packageIndexTable;

    /**

     * Initialize from another object. Note that both objects use the same

     * references (shallow copy). Use copy() for a physical copy.

     */

    public ModulePackages(final ModulePackages c) {

        this(c.getNameIndex(), c.getLength(), c.getPackageIndexTable(), c.getConstantPool());

    }

    /**

     * @param nameIndex Index in constant pool

     * @param length Content length in bytes

     * @param packageIndexTable Table of indices in constant pool

     * @param constantPool Array of constants

     */

    public ModulePackages(final int nameIndex, final int length, final int[] packageIndexTable,

            final ConstantPool constantPool) {

        super(Const.ATTR_MODULE_PACKAGES, nameIndex, length, constantPool);

        this.packageIndexTable = packageIndexTable != null ? packageIndexTable : new int[0];

    }

    /**

     * Construct object from input stream.

     * @param name_index Index in constant pool

     * @param length Content length in bytes

     * @param input Input stream

     * @param constant_pool Array of constants

     * @throws IOException

     */

    ModulePackages(final int name_index, final int length, final DataInput input, final ConstantPool constant_pool) throws IOException {

        this(name_index, length, (int[]) null, constant_pool);

        final int number_of_packages = input.readUnsignedShort();

        packageIndexTable = new int[number_of_packages];

        for (int i = 0; i < number_of_packages; i++) {

            packageIndexTable[i] = input.readUnsignedShort();

        }

    }

    /**

     * Called by objects that are traversing the nodes of the tree implicitely

     * defined by the contents of a Java class. I.e., the hierarchy of methods,

     * fields, attributes, etc. spawns a tree of objects.

     *

     * @param v Visitor object

     */

    @Override

    public void accept( final Visitor v ) {

        v.visitModulePackages(this);

    }

    /**

     * Dump ModulePackages attribute to file stream in binary format.

     *

     * @param file Output file stream

     * @throws IOException

     */

    @Override

    public void dump( final DataOutputStream file ) throws IOException {

        super.dump(file);

        file.writeShort(packageIndexTable.length);

        for (final int index : packageIndexTable) {

            file.writeShort(index);

        }

    }

    /**

     * @return array of indices into constant pool of package names.

     */

    public int[] getPackageIndexTable() {

        return packageIndexTable;

    }

    /**

     * @return Length of package table.

     */

    public int getNumberOfPackages() {

        return packageIndexTable == null ? 0 : packageIndexTable.length;

    }

    /**

     * @return string array of package names

     */

    public String[] getPackageNames() {

        final String[] names = new String[packageIndexTable.length];

        for (int i = 0; i < packageIndexTable.length; i++) {

            names[i] = super.getConstantPool().getConstantString(packageIndexTable[i],

                    Const.CONSTANT_Package).replace('/', '.');

        }

        return names;

    }

    /**

     * @param packageIndexTable the list of package indexes

     * Also redefines number_of_packages according to table length.

     */

    public void setPackageIndexTable( final int[] packageIndexTable ) {

        this.packageIndexTable = packageIndexTable != null ? packageIndexTable : new int[0];

    }

    /**

     * @return String representation, i.e., a list of packages.

     */

    @Override

    public String toString() {

        final StringBuilder buf = new StringBuilder();

        buf.append("ModulePackages(");

        buf.append(packageIndexTable.length);

        buf.append("):\n");

        for (final int index : packageIndexTable) {

            final String package_name = super.getConstantPool().getConstantString(index, Const.CONSTANT_Package);

            buf.append("  ").append(Utility.compactClassName(package_name, false)).append("\n");

        }

        return buf.substring(0, buf.length()-1); // remove the last newline

    }

    /**

     * @return deep copy of this attribute

     */

    @Override

    public Attribute copy( final ConstantPool _constant_pool ) {

        final ModulePackages c = (ModulePackages) clone();

        if (packageIndexTable != null) {

            c.packageIndexTable = new int[packageIndexTable.length];

            System.arraycopy(packageIndexTable, 0, c.packageIndexTable, 0,

                    packageIndexTable.length);

        }

        c.setConstantPool(_constant_pool);

        return c;

    }

}