scouter.javassist.ClassMap Maven / Gradle / Ivy
/*
* Javassist, a Java-bytecode translator toolkit.
* Copyright (C) 1999- Shigeru Chiba. All Rights Reserved.
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. Alternatively, the contents of this file may be used under
* the terms of the GNU Lesser General Public License Version 2.1 or later,
* or the Apache License Version 2.0.
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*/
package scouter.javassist;
import scouter.javassist.bytecode.Descriptor;
/**
* A hash table associating class names with different names.
*
* This hashtable is used for replacing class names in a class
* definition or a method body. Define a subclass of this class
* if a more complex mapping algorithm is needed. For example,
*
*
class MyClassMap extends ClassMap {
* public Object get(Object jvmClassName) {
* String name = toJavaName((String)jvmClassName);
* if (name.startsWith("java."))
* return toJvmName("java2." + name.substring(5));
* else
* return super.get(jvmClassName);
* }
* }
*
* This subclass maps java.lang.String to
* java2.lang.String. Note that get()
* receives and returns the internal representation of a class name.
* For example, the internal representation of java.lang.String
* is java/lang/String.
*
*
Note that this is a map from String to String.
*
* @see #get(Object)
* @see CtClass#replaceClassName(ClassMap)
* @see CtNewMethod#copy(CtMethod,String,CtClass,ClassMap)
*/
public class ClassMap extends java.util.HashMap {
private ClassMap parent;
/**
* Constructs a hash table.
*/
public ClassMap() { parent = null; }
ClassMap(ClassMap map) { parent = map; }
/**
* Maps a class name to another name in this hashtable.
* The names are obtained with calling Class.getName().
* This method translates the given class names into the
* internal form used in the JVM before putting it in
* the hashtable.
*
* @param oldname the original class name
* @param newname the substituted class name.
*/
public void put(CtClass oldname, CtClass newname) {
put(oldname.getName(), newname.getName());
}
/**
* Maps a class name to another name in this hashtable.
* If the hashtable contains another mapping from the same
* class name, the old mapping is replaced.
* This method translates the given class names into the
* internal form used in the JVM before putting it in
* the hashtable.
*
*
If oldname is identical to
* newname, then this method does not
* perform anything; it does not record the mapping from
* oldname to newname. See
* fix method.
*
* @param oldname the original class name.
* @param newname the substituted class name.
* @see #fix(String)
*/
public void put(String oldname, String newname) {
if (oldname == newname)
return;
String oldname2 = toJvmName(oldname);
String s = (String)get(oldname2);
if (s == null || !s.equals(oldname2))
super.put(oldname2, toJvmName(newname));
}
/**
* Is equivalent to put() except that
* the given mapping is not recorded into the hashtable
* if another mapping from oldname is
* already included.
*
* @param oldname the original class name.
* @param newname the substituted class name.
*/
public void putIfNone(String oldname, String newname) {
if (oldname == newname)
return;
String oldname2 = toJvmName(oldname);
String s = (String)get(oldname2);
if (s == null)
super.put(oldname2, toJvmName(newname));
}
protected final void put0(Object oldname, Object newname) {
super.put(oldname, newname);
}
/**
* Returns the class name to wihch the given jvmClassName
* is mapped. A subclass of this class should override this method.
*
*
This method receives and returns the internal representation of
* class name used in the JVM.
*
* @see #toJvmName(String)
* @see #toJavaName(String)
*/
public Object get(Object jvmClassName) {
Object found = super.get(jvmClassName);
if (found == null && parent != null)
return parent.get(jvmClassName);
else
return found;
}
/**
* Prevents a mapping from the specified class name to another name.
*/
public void fix(CtClass clazz) {
fix(clazz.getName());
}
/**
* Prevents a mapping from the specified class name to another name.
*/
public void fix(String name) {
String name2 = toJvmName(name);
super.put(name2, name2);
}
/**
* Converts a class name into the internal representation used in
* the JVM.
*/
public static String toJvmName(String classname) {
return Descriptor.toJvmName(classname);
}
/**
* Converts a class name from the internal representation used in
* the JVM to the normal one used in Java.
*/
public static String toJavaName(String classname) {
return Descriptor.toJavaName(classname);
}
}