org.apache.openjpa.enhance.AsmAdaptor Maven / Gradle / Ivy
/*
* 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.openjpa.enhance;
import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URLDecoder;
import org.apache.xbean.asm6.ClassReader;
import org.apache.xbean.asm6.ClassVisitor;
import org.apache.xbean.asm6.ClassWriter;
import org.apache.xbean.asm6.Opcodes;
import serp.bytecode.BCClass;
import static java.util.Arrays.asList;
/**
* Use ASM to add required StackMapTable attribute to the byte code generated by
* Serp.
*/
public final class AsmAdaptor {
private static final boolean USE_ASM = System.getProperty("java.version").compareTo("1.6") > 0;
private static final int Java7_MajorVersion = 51;
@SuppressWarnings("deprecation")
public static void write(BCClass bc) throws IOException {
if (bc.getMajorVersion() < Java7_MajorVersion) {
bc.write();
} else {
String name = bc.getName();
int dotIndex = name.lastIndexOf('.') + 1;
name = name.substring(dotIndex);
Class type = bc.getType();
OutputStream out = new FileOutputStream(
URLDecoder.decode(type.getResource(name + ".class").getFile()));
try {
writeJava7(bc, out);
} finally {
out.flush();
out.close();
}
}
}
public static void write(BCClass bc, File outFile) throws IOException {
if (bc.getMajorVersion() < Java7_MajorVersion) {
bc.write(outFile);
} else {
OutputStream out = new FileOutputStream(outFile);
try {
writeJava7(bc, out);
} finally {
out.flush();
out.close();
}
}
}
public static byte[] toByteArray(BCClass bc, byte[] returnBytes) throws IOException {
if (bc.getMajorVersion() >= Java7_MajorVersion) {
returnBytes = toJava7ByteArray(bc, returnBytes);
}
return returnBytes;
}
private static void writeJava7(BCClass bc, OutputStream out) throws IOException {
byte[] java7Bytes = toJava7ByteArray(bc, bc.toByteArray());
out.write(java7Bytes);
}
private static byte[] toJava7ByteArray(BCClass bc, byte[] classBytes) throws IOException {
ByteArrayInputStream bais = new ByteArrayInputStream(classBytes);
BufferedInputStream bis = new BufferedInputStream(bais);
ClassWriter cw = new BCClassWriter(ClassWriter.COMPUTE_FRAMES, bc.getClassLoader());
ClassReader cr = new ClassReader(bis);
cr.accept(cw, 0);
return cw.toByteArray();
}
public static boolean use()
{
return USE_ASM;
}
public static boolean isEnhanced(final byte[] b)
{
if (b == null)
{
return false;
}
final ClassReader cr = new ClassReader(b);
try
{
cr.accept(new ClassVisitor(Opcodes.ASM6)
{
@Override
public void visit(final int i, final int i1,
final String name, final String s,
final String parent, final String[] interfaces)
{
boolean enhanced = interfaces != null && interfaces.length > 0 &&
asList(interfaces).contains("org/apache/openjpa/enhance/PersistenceCapable");
if (!enhanced && name != null && parent != null &&
!"java/lang/Object".equals(parent) && !name.equals(parent)) {
enhanced = isEnhanced(bytes(parent));
}
throw new EnhancedStatusException(enhanced);
}
}, 0);
return false;
} catch (final EnhancedStatusException e) {
return e.status;
} catch (final Exception e) {
return false;
}
}
private static byte[] bytes(final String type)
{
final ByteArrayOutputStream baos = new ByteArrayOutputStream(1024);
final InputStream stream = Thread.currentThread().getContextClassLoader()
.getResourceAsStream(type + ".class");
if (stream == null) {
return null;
}
try {
int c;
byte[] buffer = new byte[1024];
while ((c = stream.read(buffer)) >= 0) {
baos.write(buffer, 0, c);
}
} catch (IOException e) {
return null;
} finally {
try {
stream.close();
} catch (IOException e) {
// no-op
}
}
return baos.toByteArray();
}
private static class BCClassWriter extends ClassWriter {
private final ClassLoader _loader;
BCClassWriter(int flags, ClassLoader loader) {
super(flags);
_loader = loader;
}
@Override
protected String getCommonSuperClass(String type1, String type2) {
Class class1;
Class class2;
try {
class1 = _loader.loadClass(type1.replace('/', '.'));
class2 = _loader.loadClass(type2.replace('/', '.'));
} catch (ClassNotFoundException ex) {
throw new RuntimeException(ex);
}
if (class1.isAssignableFrom(class2)) {
return type1;
}
if (class2.isAssignableFrom(class1)) {
return type2;
}
if (class1.isInterface() || class2.isInterface()) {
return "java/lang/Object";
}
do {
class1 = class1.getSuperclass();
} while (!class1.isAssignableFrom(class2));
return class1.getName().replace('.', '/');
}
}
private static class EnhancedStatusException extends RuntimeException {
private final boolean status;
private EnhancedStatusException(final boolean status) {
this.status = status;
}
}
}