scouter.javassist.SerialVersionUID 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.ClassFile;
import scouter.javassist.bytecode.Descriptor;
import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.lang.reflect.Modifier;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;
import java.util.Comparator;
/**
* Utility for calculating serialVersionUIDs for Serializable classes.
*
* @author Bob Lee ([email protected])
* @author modified by Shigeru Chiba
*/
public class SerialVersionUID {
/**
* Adds serialVersionUID if one does not already exist. Call this before
* modifying a class to maintain serialization compatability.
*/
public static void setSerialVersionUID(CtClass clazz)
throws CannotCompileException, NotFoundException
{
// check for pre-existing field.
try {
clazz.getDeclaredField("serialVersionUID");
return;
}
catch (NotFoundException e) {}
// check if the class is serializable.
if (!isSerializable(clazz))
return;
// add field with default value.
CtField field = new CtField(CtClass.longType, "serialVersionUID",
clazz);
field.setModifiers(Modifier.PRIVATE | Modifier.STATIC |
Modifier.FINAL);
clazz.addField(field, calculateDefault(clazz) + "L");
}
/**
* Does the class implement Serializable?
*/
private static boolean isSerializable(CtClass clazz)
throws NotFoundException
{
ClassPool pool = clazz.getClassPool();
return clazz.subtypeOf(pool.get("java.io.Serializable"));
}
/**
* Calculate default value. See Java Serialization Specification, Stream
* Unique Identifiers.
*
* @since 3.20
*/
public static long calculateDefault(CtClass clazz)
throws CannotCompileException
{
try {
ByteArrayOutputStream bout = new ByteArrayOutputStream();
DataOutputStream out = new DataOutputStream(bout);
ClassFile classFile = clazz.getClassFile();
// class name.
String javaName = javaName(clazz);
out.writeUTF(javaName);
CtMethod[] methods = clazz.getDeclaredMethods();
// class modifiers.
int classMods = clazz.getModifiers();
if ((classMods & Modifier.INTERFACE) != 0)
if (methods.length > 0)
classMods = classMods | Modifier.ABSTRACT;
else
classMods = classMods & ~Modifier.ABSTRACT;
out.writeInt(classMods);
// interfaces.
String[] interfaces = classFile.getInterfaces();
for (int i = 0; i < interfaces.length; i++)
interfaces[i] = javaName(interfaces[i]);
Arrays.sort(interfaces);
for (int i = 0; i < interfaces.length; i++)
out.writeUTF(interfaces[i]);
// fields.
CtField[] fields = clazz.getDeclaredFields();
Arrays.sort(fields, new Comparator() {
public int compare(Object o1, Object o2) {
CtField field1 = (CtField)o1;
CtField field2 = (CtField)o2;
return field1.getName().compareTo(field2.getName());
}
});
for (int i = 0; i < fields.length; i++) {
CtField field = (CtField) fields[i];
int mods = field.getModifiers();
if (((mods & Modifier.PRIVATE) == 0) ||
((mods & (Modifier.STATIC | Modifier.TRANSIENT)) == 0)) {
out.writeUTF(field.getName());
out.writeInt(mods);
out.writeUTF(field.getFieldInfo2().getDescriptor());
}
}
// static initializer.
if (classFile.getStaticInitializer() != null) {
out.writeUTF("");
out.writeInt(Modifier.STATIC);
out.writeUTF("()V");
}
// constructors.
CtConstructor[] constructors = clazz.getDeclaredConstructors();
Arrays.sort(constructors, new Comparator() {
public int compare(Object o1, Object o2) {
CtConstructor c1 = (CtConstructor)o1;
CtConstructor c2 = (CtConstructor)o2;
return c1.getMethodInfo2().getDescriptor().compareTo(
c2.getMethodInfo2().getDescriptor());
}
});
for (int i = 0; i < constructors.length; i++) {
CtConstructor constructor = constructors[i];
int mods = constructor.getModifiers();
if ((mods & Modifier.PRIVATE) == 0) {
out.writeUTF("");
out.writeInt(mods);
out.writeUTF(constructor.getMethodInfo2()
.getDescriptor().replace('/', '.'));
}
}
// methods.
Arrays.sort(methods, new Comparator() {
public int compare(Object o1, Object o2) {
CtMethod m1 = (CtMethod)o1;
CtMethod m2 = (CtMethod)o2;
int value = m1.getName().compareTo(m2.getName());
if (value == 0)
value = m1.getMethodInfo2().getDescriptor()
.compareTo(m2.getMethodInfo2().getDescriptor());
return value;
}
});
for (int i = 0; i < methods.length; i++) {
CtMethod method = methods[i];
int mods = method.getModifiers()
& (Modifier.PUBLIC | Modifier.PRIVATE
| Modifier.PROTECTED | Modifier.STATIC
| Modifier.FINAL | Modifier.SYNCHRONIZED
| Modifier.NATIVE | Modifier.ABSTRACT | Modifier.STRICT);
if ((mods & Modifier.PRIVATE) == 0) {
out.writeUTF(method.getName());
out.writeInt(mods);
out.writeUTF(method.getMethodInfo2()
.getDescriptor().replace('/', '.'));
}
}
// calculate hash.
out.flush();
MessageDigest digest = MessageDigest.getInstance("SHA");
byte[] digested = digest.digest(bout.toByteArray());
long hash = 0;
for (int i = Math.min(digested.length, 8) - 1; i >= 0; i--)
hash = (hash << 8) | (digested[i] & 0xFF);
return hash;
}
catch (IOException e) {
throw new CannotCompileException(e);
}
catch (NoSuchAlgorithmException e) {
throw new CannotCompileException(e);
}
}
private static String javaName(CtClass clazz) {
return Descriptor.toJavaName(Descriptor.toJvmName(clazz));
}
private static String javaName(String name) {
return Descriptor.toJavaName(Descriptor.toJvmName(name));
}
}