trunk/src/main/org/apache/tools/ant/taskdefs/optional/depend/constantpool/ConstantPool.java - ant - Git at Google

 /*
  *  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
  *  limitations under the License.
  *
  */
 package org.apache.tools.ant.taskdefs.optional.depend.constantpool;

 import java.io.DataInputStream;
 import java.io.IOException;
 import java.util.Enumeration;
 import java.util.Hashtable;
 import java.util.Vector;

 /**
  * The constant pool of a Java class. The constant pool is a collection of
  * constants used in a Java class file. It stores strings, constant values,
  * class names, method names, field names etc.
  *
  * @see <a href="http://java.sun.com/docs/books/vmspec/">The Java Virtual
  *      Machine Specification</a>
  */
 public class ConstantPool {

     /** The entries in the constant pool. */
     private Vector entries;

     /**
      * A Hashtable of UTF8 entries - used to get constant pool indexes of
      * the UTF8 values quickly
      */
     private Hashtable utf8Indexes;

     /** Initialise the constant pool. */
     public ConstantPool() {
         entries = new Vector();

         // The zero index is never present in the constant pool itself so
         // we add a null entry for it
         entries.addElement(null);

         utf8Indexes = new Hashtable();
     }

     /**
      * Read the constant pool from a class input stream.
      *
      * @param classStream the DataInputStream of a class file.
      * @exception IOException if there is a problem reading the constant pool
      *      from the stream
      */
     public void read(DataInputStream classStream) throws IOException {
         int numEntries = classStream.readUnsignedShort();

         for (int i = 1; i < numEntries;) {
             ConstantPoolEntry nextEntry
                  = ConstantPoolEntry.readEntry(classStream);

             i += nextEntry.getNumEntries();

             addEntry(nextEntry);
         }
     }

     /**
      * Get the size of the constant pool.
      *
      * @return the size of the constant pool
      */
     public int size() {
         return entries.size();
     }

     /**
      * Add an entry to the constant pool.
      *
      * @param entry the new entry to be added to the constant pool.
      * @return the index into the constant pool at which the entry is
      *      stored.
      */
     public int addEntry(ConstantPoolEntry entry) {
         int index = entries.size();

         entries.addElement(entry);

         int numSlots = entry.getNumEntries();

         // add null entries for any additional slots required.
         for (int j = 0; j < numSlots - 1; ++j) {
             entries.addElement(null);
         }

         if (entry instanceof Utf8CPInfo) {
             Utf8CPInfo utf8Info = (Utf8CPInfo) entry;

             utf8Indexes.put(utf8Info.getValue(), new Integer(index));
         }

         return index;
     }

     /**
      * Resolve the entries in the constant pool. Resolution of the constant
      * pool involves transforming indexes to other constant pool entries
      * into the actual data for that entry.
      */
     public void resolve() {
         for (Enumeration i = entries.elements(); i.hasMoreElements();) {
             ConstantPoolEntry poolInfo = (ConstantPoolEntry) i.nextElement();

             if (poolInfo != null && !poolInfo.isResolved()) {
                 poolInfo.resolve(this);
             }
         }
     }


     /**
      * Get an constant pool entry at a particular index.
      *
      * @param index the index into the constant pool.
      * @return the constant pool entry at that index.
      */
     public ConstantPoolEntry getEntry(int index) {
         return (ConstantPoolEntry) entries.elementAt(index);
     }

     /**
      * Get the index of a given UTF8 constant pool entry.
      *
      * @param value the string value of the UTF8 entry.
      * @return the index at which the given string occurs in the constant
      *      pool or -1 if the value does not occur.
      */
     public int getUTF8Entry(String value) {
         int index = -1;
         Integer indexInteger = (Integer) utf8Indexes.get(value);

         if (indexInteger != null) {
             index = indexInteger.intValue();
         }

         return index;
     }

     /**
      * Get the index of a given CONSTANT_CLASS entry in the constant pool.
      *
      * @param className the name of the class for which the class entry
      *      index is required.
      * @return the index at which the given class entry occurs in the
      *      constant pool or -1 if the value does not occur.
      */
     public int getClassEntry(String className) {
         int index = -1;

         for (int i = 0; i < entries.size() && index == -1; ++i) {
             Object element = entries.elementAt(i);

             if (element instanceof ClassCPInfo) {
                 ClassCPInfo classinfo = (ClassCPInfo) element;

                 if (classinfo.getClassName().equals(className)) {
                     index = i;
                 }
             }
         }

         return index;
     }

     /**
      * Get the index of a given constant value entry in the constant pool.
      *
      * @param constantValue the constant value for which the index is
      *      required.
      * @return the index at which the given value entry occurs in the
      *      constant pool or -1 if the value does not occur.
      */
     public int getConstantEntry(Object constantValue) {
         int index = -1;

         for (int i = 0; i < entries.size() && index == -1; ++i) {
             Object element = entries.elementAt(i);

             if (element instanceof ConstantCPInfo) {
                 ConstantCPInfo constantEntry = (ConstantCPInfo) element;

                 if (constantEntry.getValue().equals(constantValue)) {
                     index = i;
                 }
             }
         }

         return index;
     }

     /**
      * Get the index of a given CONSTANT_METHODREF entry in the constant
      * pool.
      *
      * @param methodClassName the name of the class which contains the
      *      method being referenced.
      * @param methodName the name of the method being referenced.
      * @param methodType the type descriptor of the method being referenced.
      * @return the index at which the given method ref entry occurs in the
      *      constant pool or -1 if the value does not occur.
      */
     public int getMethodRefEntry(String methodClassName, String methodName,
                                  String methodType) {
         int index = -1;

         for (int i = 0; i < entries.size() && index == -1; ++i) {
             Object element = entries.elementAt(i);

             if (element instanceof MethodRefCPInfo) {
                 MethodRefCPInfo methodRefEntry = (MethodRefCPInfo) element;

                 if (methodRefEntry.getMethodClassName().equals(methodClassName)
                      && methodRefEntry.getMethodName().equals(methodName)
                      && methodRefEntry.getMethodType().equals(methodType)) {
                     index = i;
                 }
             }
         }

         return index;
     }

     /**
      * Get the index of a given CONSTANT_INTERFACEMETHODREF entry in the
      * constant pool.
      *
      * @param interfaceMethodClassName the name of the interface which
      *      contains the method being referenced.
      * @param interfaceMethodName the name of the method being referenced.
      * @param interfaceMethodType the type descriptor of the method being
      *      referenced.
      * @return the index at which the given method ref entry occurs in the
      *      constant pool or -1 if the value does not occur.
      */
     public int getInterfaceMethodRefEntry(String interfaceMethodClassName,
                                           String interfaceMethodName,
                                           String interfaceMethodType) {
         int index = -1;

         for (int i = 0; i < entries.size() && index == -1; ++i) {
             Object element = entries.elementAt(i);

             if (element instanceof InterfaceMethodRefCPInfo) {
                 InterfaceMethodRefCPInfo interfaceMethodRefEntry
                      = (InterfaceMethodRefCPInfo) element;

                 if (interfaceMethodRefEntry.getInterfaceMethodClassName().equals(
                         interfaceMethodClassName)
                      && interfaceMethodRefEntry.getInterfaceMethodName().equals(
                          interfaceMethodName)
                      && interfaceMethodRefEntry.getInterfaceMethodType().equals(
                          interfaceMethodType)) {
                     index = i;
                 }
             }
         }

         return index;
     }

     /**
      * Get the index of a given CONSTANT_FIELDREF entry in the constant
      * pool.
      *
      * @param fieldClassName the name of the class which contains the field
      *      being referenced.
      * @param fieldName the name of the field being referenced.
      * @param fieldType the type descriptor of the field being referenced.
      * @return the index at which the given field ref entry occurs in the
      *      constant pool or -1 if the value does not occur.
      */
     public int getFieldRefEntry(String fieldClassName, String fieldName,
                                 String fieldType) {
         int index = -1;

         for (int i = 0; i < entries.size() && index == -1; ++i) {
             Object element = entries.elementAt(i);

             if (element instanceof FieldRefCPInfo) {
                 FieldRefCPInfo fieldRefEntry = (FieldRefCPInfo) element;

                 if (fieldRefEntry.getFieldClassName().equals(fieldClassName)
                      && fieldRefEntry.getFieldName().equals(fieldName)
                      && fieldRefEntry.getFieldType().equals(fieldType)) {
                     index = i;
                 }
             }
         }

         return index;
     }

     /**
      * Get the index of a given CONSTANT_NAMEANDTYPE entry in the constant
      * pool.
      *
      * @param name the name
      * @param type the type
      * @return the index at which the given NameAndType entry occurs in the
      *      constant pool or -1 if the value does not occur.
      */
     public int getNameAndTypeEntry(String name, String type) {
         int index = -1;

         for (int i = 0; i < entries.size() && index == -1; ++i) {
             Object element = entries.elementAt(i);

             if (element instanceof NameAndTypeCPInfo) {
                 NameAndTypeCPInfo nameAndTypeEntry
                     = (NameAndTypeCPInfo) element;

                 if (nameAndTypeEntry.getName().equals(name)
                      && nameAndTypeEntry.getType().equals(type)) {
                     index = i;
                 }
             }
         }

         return index;
     }

     /**
      * Dump the constant pool to a string.
      *
      * @return the constant pool entries as strings
      */
     public String toString() {
         StringBuffer sb = new StringBuffer("\n");
         int size = entries.size();

         for (int i = 0; i < size; ++i) {
             sb.append("[" + i + "] = " + getEntry(i) + "\n");
         }

         return sb.toString();
     }

 }
	/*
	* 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
	* limitations under the License.
	*
	*/
	package org.apache.tools.ant.taskdefs.optional.depend.constantpool;

	import java.io.DataInputStream;
	import java.io.IOException;
	import java.util.Enumeration;
	import java.util.Hashtable;
	import java.util.Vector;

	/**
	* The constant pool of a Java class. The constant pool is a collection of
	* constants used in a Java class file. It stores strings, constant values,
	* class names, method names, field names etc.
	*
	* @see <a href="http://java.sun.com/docs/books/vmspec/">The Java Virtual
	* Machine Specification</a>
	*/
	public class ConstantPool {

	/** The entries in the constant pool. */
	private Vector entries;

	/**
	* A Hashtable of UTF8 entries - used to get constant pool indexes of
	* the UTF8 values quickly
	*/
	private Hashtable utf8Indexes;

	/** Initialise the constant pool. */
	public ConstantPool() {
	entries = new Vector();

	// The zero index is never present in the constant pool itself so
	// we add a null entry for it
	entries.addElement(null);

	utf8Indexes = new Hashtable();
	}

	/**
	* Read the constant pool from a class input stream.
	*
	* @param classStream the DataInputStream of a class file.
	* @exception IOException if there is a problem reading the constant pool
	* from the stream
	*/
	public void read(DataInputStream classStream) throws IOException {
	int numEntries = classStream.readUnsignedShort();

	for (int i = 1; i < numEntries;) {
	ConstantPoolEntry nextEntry
	= ConstantPoolEntry.readEntry(classStream);

	i += nextEntry.getNumEntries();

	addEntry(nextEntry);
	}
	}

	/**
	* Get the size of the constant pool.
	*
	* @return the size of the constant pool
	*/
	public int size() {
	return entries.size();
	}

	/**
	* Add an entry to the constant pool.
	*
	* @param entry the new entry to be added to the constant pool.
	* @return the index into the constant pool at which the entry is
	* stored.
	*/
	public int addEntry(ConstantPoolEntry entry) {
	int index = entries.size();

	entries.addElement(entry);

	int numSlots = entry.getNumEntries();

	// add null entries for any additional slots required.
	for (int j = 0; j < numSlots - 1; ++j) {
	entries.addElement(null);
	}

	if (entry instanceof Utf8CPInfo) {
	Utf8CPInfo utf8Info = (Utf8CPInfo) entry;

	utf8Indexes.put(utf8Info.getValue(), new Integer(index));
	}

	return index;
	}

	/**
	* Resolve the entries in the constant pool. Resolution of the constant
	* pool involves transforming indexes to other constant pool entries
	* into the actual data for that entry.
	*/
	public void resolve() {
	for (Enumeration i = entries.elements(); i.hasMoreElements();) {
	ConstantPoolEntry poolInfo = (ConstantPoolEntry) i.nextElement();

	if (poolInfo != null && !poolInfo.isResolved()) {
	poolInfo.resolve(this);
	}
	}
	}


	/**
	* Get an constant pool entry at a particular index.
	*
	* @param index the index into the constant pool.
	* @return the constant pool entry at that index.
	*/
	public ConstantPoolEntry getEntry(int index) {
	return (ConstantPoolEntry) entries.elementAt(index);
	}

	/**
	* Get the index of a given UTF8 constant pool entry.
	*
	* @param value the string value of the UTF8 entry.
	* @return the index at which the given string occurs in the constant
	* pool or -1 if the value does not occur.
	*/
	public int getUTF8Entry(String value) {
	int index = -1;
	Integer indexInteger = (Integer) utf8Indexes.get(value);

	if (indexInteger != null) {
	index = indexInteger.intValue();
	}

	return index;
	}

	/**
	* Get the index of a given CONSTANT_CLASS entry in the constant pool.
	*
	* @param className the name of the class for which the class entry
	* index is required.
	* @return the index at which the given class entry occurs in the
	* constant pool or -1 if the value does not occur.
	*/
	public int getClassEntry(String className) {
	int index = -1;

	for (int i = 0; i < entries.size() && index == -1; ++i) {
	Object element = entries.elementAt(i);

	if (element instanceof ClassCPInfo) {
	ClassCPInfo classinfo = (ClassCPInfo) element;

	if (classinfo.getClassName().equals(className)) {
	index = i;
	}
	}
	}

	return index;
	}

	/**
	* Get the index of a given constant value entry in the constant pool.
	*
	* @param constantValue the constant value for which the index is
	* required.
	* @return the index at which the given value entry occurs in the
	* constant pool or -1 if the value does not occur.
	*/
	public int getConstantEntry(Object constantValue) {
	int index = -1;

	for (int i = 0; i < entries.size() && index == -1; ++i) {
	Object element = entries.elementAt(i);

	if (element instanceof ConstantCPInfo) {
	ConstantCPInfo constantEntry = (ConstantCPInfo) element;

	if (constantEntry.getValue().equals(constantValue)) {
	index = i;
	}
	}
	}

	return index;
	}

	/**
	* Get the index of a given CONSTANT_METHODREF entry in the constant
	* pool.
	*
	* @param methodClassName the name of the class which contains the
	* method being referenced.
	* @param methodName the name of the method being referenced.
	* @param methodType the type descriptor of the method being referenced.
	* @return the index at which the given method ref entry occurs in the
	* constant pool or -1 if the value does not occur.
	*/
	public int getMethodRefEntry(String methodClassName, String methodName,
	String methodType) {
	int index = -1;

	for (int i = 0; i < entries.size() && index == -1; ++i) {
	Object element = entries.elementAt(i);

	if (element instanceof MethodRefCPInfo) {
	MethodRefCPInfo methodRefEntry = (MethodRefCPInfo) element;

	if (methodRefEntry.getMethodClassName().equals(methodClassName)
	&& methodRefEntry.getMethodName().equals(methodName)
	&& methodRefEntry.getMethodType().equals(methodType)) {
	index = i;
	}
	}
	}

	return index;
	}

	/**
	* Get the index of a given CONSTANT_INTERFACEMETHODREF entry in the
	* constant pool.
	*
	* @param interfaceMethodClassName the name of the interface which
	* contains the method being referenced.
	* @param interfaceMethodName the name of the method being referenced.
	* @param interfaceMethodType the type descriptor of the method being
	* referenced.
	* @return the index at which the given method ref entry occurs in the
	* constant pool or -1 if the value does not occur.
	*/
	public int getInterfaceMethodRefEntry(String interfaceMethodClassName,
	String interfaceMethodName,
	String interfaceMethodType) {
	int index = -1;

	for (int i = 0; i < entries.size() && index == -1; ++i) {
	Object element = entries.elementAt(i);

	if (element instanceof InterfaceMethodRefCPInfo) {
	InterfaceMethodRefCPInfo interfaceMethodRefEntry
	= (InterfaceMethodRefCPInfo) element;

	if (interfaceMethodRefEntry.getInterfaceMethodClassName().equals(
	interfaceMethodClassName)
	&& interfaceMethodRefEntry.getInterfaceMethodName().equals(
	interfaceMethodName)
	&& interfaceMethodRefEntry.getInterfaceMethodType().equals(
	interfaceMethodType)) {
	index = i;
	}
	}
	}

	return index;
	}

	/**
	* Get the index of a given CONSTANT_FIELDREF entry in the constant
	* pool.
	*
	* @param fieldClassName the name of the class which contains the field
	* being referenced.
	* @param fieldName the name of the field being referenced.
	* @param fieldType the type descriptor of the field being referenced.
	* @return the index at which the given field ref entry occurs in the
	* constant pool or -1 if the value does not occur.
	*/
	public int getFieldRefEntry(String fieldClassName, String fieldName,
	String fieldType) {
	int index = -1;

	for (int i = 0; i < entries.size() && index == -1; ++i) {
	Object element = entries.elementAt(i);

	if (element instanceof FieldRefCPInfo) {
	FieldRefCPInfo fieldRefEntry = (FieldRefCPInfo) element;

	if (fieldRefEntry.getFieldClassName().equals(fieldClassName)
	&& fieldRefEntry.getFieldName().equals(fieldName)
	&& fieldRefEntry.getFieldType().equals(fieldType)) {
	index = i;
	}
	}
	}

	return index;
	}

	/**
	* Get the index of a given CONSTANT_NAMEANDTYPE entry in the constant
	* pool.
	*
	* @param name the name
	* @param type the type
	* @return the index at which the given NameAndType entry occurs in the
	* constant pool or -1 if the value does not occur.
	*/
	public int getNameAndTypeEntry(String name, String type) {
	int index = -1;

	for (int i = 0; i < entries.size() && index == -1; ++i) {
	Object element = entries.elementAt(i);

	if (element instanceof NameAndTypeCPInfo) {
	NameAndTypeCPInfo nameAndTypeEntry
	= (NameAndTypeCPInfo) element;

	if (nameAndTypeEntry.getName().equals(name)
	&& nameAndTypeEntry.getType().equals(type)) {
	index = i;
	}
	}
	}

	return index;
	}

	/**
	* Dump the constant pool to a string.
	*
	* @return the constant pool entries as strings
	*/
	public String toString() {
	StringBuffer sb = new StringBuffer("\n");
	int size = entries.size();

	for (int i = 0; i < size; ++i) {
	sb.append("[" + i + "] = " + getEntry(i) + "\n");
	}

	return sb.toString();
	}

	}