/*
* 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 javassist.convert;
import javassist.
ClassPool;
import javassist.
CtClass;
import javassist.
CtField;
import javassist.
Modifier;
import javassist.
NotFoundException;
import javassist.bytecode.
BadBytecode;
import javassist.bytecode.
CodeIterator;
import javassist.bytecode.
ConstPool;
public class
TransformReadField extends
Transformer {
protected
String fieldname;
protected
CtClass fieldClass;
protected boolean
isPrivate;
protected
String methodClassname,
methodName;
public
TransformReadField(
Transformer next,
CtField field,
String methodClassname,
String methodName)
{
super(
next);
this.
fieldClass =
field.
getDeclaringClass();
this.
fieldname =
field.
getName();
this.
methodClassname =
methodClassname;
this.
methodName =
methodName;
this.
isPrivate =
Modifier.
isPrivate(
field.
getModifiers());
}
static
String isField(
ClassPool pool,
ConstPool cp,
CtClass fclass,
String fname, boolean
is_private, int
index) {
if (!
cp.
getFieldrefName(
index).
equals(
fname))
return null;
try {
CtClass c =
pool.
get(
cp.
getFieldrefClassName(
index));
if (
c ==
fclass || (!
is_private &&
isFieldInSuper(
c,
fclass,
fname)))
return
cp.
getFieldrefType(
index);
}
catch (
NotFoundException e) {}
return null;
}
static boolean
isFieldInSuper(
CtClass clazz,
CtClass fclass,
String fname) {
if (!
clazz.
subclassOf(
fclass))
return false;
try {
CtField f =
clazz.
getField(
fname);
return
f.
getDeclaringClass() ==
fclass;
}
catch (
NotFoundException e) {}
return false;
}
@
Override
public int
transform(
CtClass tclazz, int
pos,
CodeIterator iterator,
ConstPool cp) throws
BadBytecode
{
int
c =
iterator.
byteAt(
pos);
if (
c ==
GETFIELD ||
c ==
GETSTATIC) {
int
index =
iterator.
u16bitAt(
pos + 1);
String typedesc =
isField(
tclazz.
getClassPool(),
cp,
fieldClass,
fieldname,
isPrivate,
index);
if (
typedesc != null) {
if (
c ==
GETSTATIC) {
iterator.
move(
pos);
pos =
iterator.
insertGap(1); // insertGap() may insert 4 bytes.
iterator.
writeByte(
ACONST_NULL,
pos);
pos =
iterator.
next();
}
String type = "(Ljava/lang/Object;)" +
typedesc;
int
mi =
cp.
addClassInfo(
methodClassname);
int
methodref =
cp.
addMethodrefInfo(
mi,
methodName,
type);
iterator.
writeByte(
INVOKESTATIC,
pos);
iterator.
write16bit(
methodref,
pos + 1);
return
pos;
}
}
return
pos;
}
}