| /* |
| * The Apache Software License, Version 1.1 |
| * |
| * Copyright (c) 2000-2002 The Apache Software Foundation. All rights |
| * reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * 3. The end-user documentation included with the redistribution, if |
| * any, must include the following acknowlegement: |
| * "This product includes software developed by the |
| * Apache Software Foundation (http://www.apache.org/)." |
| * Alternately, this acknowlegement may appear in the software itself, |
| * if and wherever such third-party acknowlegements normally appear. |
| * |
| * 4. The names "The Jakarta Project", "Ant", and "Apache Software |
| * Foundation" must not be used to endorse or promote products derived |
| * from this software without prior written permission. For written |
| * permission, please contact apache@apache.org. |
| * |
| * 5. Products derived from this software may not be called "Apache" |
| * nor may "Apache" appear in their names without prior written |
| * permission of the Apache Group. |
| * |
| * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED |
| * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR |
| * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
| * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| * ==================================================================== |
| * |
| * This software consists of voluntary contributions made by many |
| * individuals on behalf of the Apache Software Foundation. For more |
| * information on the Apache Software Foundation, please see |
| * <http://www.apache.org/>. |
| */ |
| package org.apache.tools.ant.taskdefs.optional.depend.constantpool; |
| |
| import java.io.DataInputStream; |
| import java.io.IOException; |
| |
| /** |
| * An entry in the constant pool. This class contains a represenation of the |
| * constant pool entries. It is an abstract base class for all the different |
| * forms of constant pool entry. |
| * |
| * @author Conor MacNeill |
| * @see ConstantPool |
| */ |
| public abstract class ConstantPoolEntry { |
| |
| /** Tag value for UTF8 entries. */ |
| public static final int CONSTANT_UTF8 = 1; |
| |
| /** Tag value for Integer entries. */ |
| public static final int CONSTANT_INTEGER = 3; |
| |
| /** Tag value for Float entries. */ |
| public static final int CONSTANT_FLOAT = 4; |
| |
| /** Tag value for Long entries. */ |
| public static final int CONSTANT_LONG = 5; |
| |
| /** Tag value for Double entries. */ |
| public static final int CONSTANT_DOUBLE = 6; |
| |
| /** Tag value for Class entries. */ |
| public static final int CONSTANT_CLASS = 7; |
| |
| /** Tag value for String entries. */ |
| public static final int CONSTANT_STRING = 8; |
| |
| /** Tag value for Field Reference entries. */ |
| public static final int CONSTANT_FIELDREF = 9; |
| |
| /** Tag value for Method Reference entries. */ |
| public static final int CONSTANT_METHODREF = 10; |
| |
| /** Tag value for Interface Method Reference entries. */ |
| public static final int CONSTANT_INTERFACEMETHODREF = 11; |
| |
| /** Tag value for Name and Type entries. */ |
| public static final int CONSTANT_NAMEANDTYPE = 12; |
| |
| /** |
| * This entry's tag which identifies the type of this constant pool |
| * entry. |
| */ |
| private int tag; |
| |
| /** |
| * The number of slots in the constant pool, occupied by this entry. |
| */ |
| private int numEntries; |
| |
| /** |
| * A flag which indiciates if this entry has been resolved or not. |
| */ |
| private boolean resolved; |
| |
| /** |
| * Initialse the constant pool entry. |
| * |
| * @param tagValue the tag value which identifies which type of constant |
| * pool entry this is. |
| * @param entries the number of constant pool entry slots this entry |
| * occupies. |
| */ |
| public ConstantPoolEntry(int tagValue, int entries) { |
| tag = tagValue; |
| numEntries = entries; |
| resolved = false; |
| } |
| |
| /** |
| * Read a constant pool entry from a stream. This is a factory method |
| * which reads a constant pool entry form a stream and returns the |
| * appropriate subclass for the entry. |
| * |
| * @param cpStream the stream from which the constant pool entry is to |
| * be read. |
| * @return the appropriate ConstantPoolEntry subclass representing the |
| * constant pool entry from the stream. |
| * @exception IOException if the constant pool entry cannot be read |
| * from the stream |
| */ |
| public static ConstantPoolEntry readEntry(DataInputStream cpStream) |
| throws IOException { |
| ConstantPoolEntry cpInfo = null; |
| int cpTag = cpStream.readUnsignedByte(); |
| |
| switch (cpTag) { |
| |
| case CONSTANT_UTF8: |
| cpInfo = new Utf8CPInfo(); |
| |
| break; |
| case CONSTANT_INTEGER: |
| cpInfo = new IntegerCPInfo(); |
| |
| break; |
| case CONSTANT_FLOAT: |
| cpInfo = new FloatCPInfo(); |
| |
| break; |
| case CONSTANT_LONG: |
| cpInfo = new LongCPInfo(); |
| |
| break; |
| case CONSTANT_DOUBLE: |
| cpInfo = new DoubleCPInfo(); |
| |
| break; |
| case CONSTANT_CLASS: |
| cpInfo = new ClassCPInfo(); |
| |
| break; |
| case CONSTANT_STRING: |
| cpInfo = new StringCPInfo(); |
| |
| break; |
| case CONSTANT_FIELDREF: |
| cpInfo = new FieldRefCPInfo(); |
| |
| break; |
| case CONSTANT_METHODREF: |
| cpInfo = new MethodRefCPInfo(); |
| |
| break; |
| case CONSTANT_INTERFACEMETHODREF: |
| cpInfo = new InterfaceMethodRefCPInfo(); |
| |
| break; |
| case CONSTANT_NAMEANDTYPE: |
| cpInfo = new NameAndTypeCPInfo(); |
| |
| break; |
| default: |
| throw new ClassFormatError("Invalid Constant Pool entry Type " |
| + cpTag); |
| } |
| |
| cpInfo.read(cpStream); |
| |
| return cpInfo; |
| } |
| |
| /** |
| * Indicates whether this entry has been resolved. In general a constant |
| * pool entry can reference another constant pool entry by its index |
| * value. Resolution involves replacing this index value with the |
| * constant pool entry at that index. |
| * |
| * @return true if this entry has been resolved. |
| */ |
| public boolean isResolved() { |
| return resolved; |
| } |
| |
| /** |
| * Resolve this constant pool entry with respect to its dependents in |
| * the constant pool. |
| * |
| * @param constantPool the constant pool of which this entry is a member |
| * and against which this entry is to be resolved. |
| */ |
| public void resolve(ConstantPool constantPool) { |
| resolved = true; |
| } |
| |
| /** |
| * read a constant pool entry from a class stream. |
| * |
| * @param cpStream the DataInputStream which contains the constant pool |
| * entry to be read. |
| * @exception IOException if there is a problem reading the entry from |
| * the stream. |
| */ |
| public abstract void read(DataInputStream cpStream) throws IOException; |
| |
| /** |
| * Get the Entry's type tag. |
| * |
| * @return The Tag value of this entry |
| */ |
| public int getTag() { |
| return tag; |
| } |
| |
| /** |
| * Get the number of Constant Pool Entry slots within the constant pool |
| * occupied by this entry. |
| * |
| * @return the number of slots used. |
| */ |
| public final int getNumEntries() { |
| return numEntries; |
| } |
| |
| } |
| |
