org.eclipse.persistence.internal.jpa.weaving.ComputeClassWriter Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of eclipselink Show documentation
Show all versions of eclipselink Show documentation
EclipseLink build based upon Git transaction 67768906cf
/*
* Copyright (c) 2000, 2018 Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2000, 2015 -2011 INRIA, France Telecom
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of Oracle nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.eclipse.persistence.internal.jpa.weaving;
import java.io.IOException;
import java.io.InputStream;
import org.eclipse.persistence.internal.libraries.asm.ClassReader;
import org.eclipse.persistence.internal.libraries.asm.ClassWriter;
import org.eclipse.persistence.internal.libraries.asm.Opcodes;
/**
* A ClassWriter that computes the common super class of two classes without
* actually loading them with a ClassLoader.
*
* @author Eric Bruneton
*/
class ComputeClassWriter extends ClassWriter {
private ClassLoader l = null;//getClass().getClassLoader();
public ComputeClassWriter(ClassLoader loader, final int flags) {
super(flags);
l = loader;
}
@Override
protected String getCommonSuperClass(final String type1, final String type2)
{
try {
ClassReader info1 = typeInfo(type1);
ClassReader info2 = typeInfo(type2);
if ((info1.getAccess() & Opcodes.ACC_INTERFACE) != 0) {
if (typeImplements(type2, info2, type1)) {
return type1;
} else {
return "java/lang/Object";
}
}
if ((info2.getAccess() & Opcodes.ACC_INTERFACE) != 0) {
if (typeImplements(type1, info1, type2)) {
return type2;
} else {
return "java/lang/Object";
}
}
StringBuilder b1 = typeAncestors(type1, info1);
StringBuilder b2 = typeAncestors(type2, info2);
String result = "java/lang/Object";
int end1 = b1.length();
int end2 = b2.length();
while (true) {
int start1 = b1.lastIndexOf(";", end1 - 1);
int start2 = b2.lastIndexOf(";", end2 - 1);
if (start1 != -1 && start2 != -1
&& end1 - start1 == end2 - start2)
{
String p1 = b1.substring(start1 + 1, end1);
String p2 = b2.substring(start2 + 1, end2);
if (p1.equals(p2)) {
result = p1;
end1 = start1;
end2 = start2;
} else {
return result;
}
} else {
return result;
}
}
} catch (IOException e) {
throw new RuntimeException(e.toString());
}
}
/**
* Returns the internal names of the ancestor classes of the given type.
*
* @param type the internal name of a class or interface.
* @param info the ClassReader corresponding to 'type'.
* @return a StringBuilder containing the ancestor classes of 'type',
* separated by ';'. The returned string has the following format:
* ";type1;type2 ... ;typeN", where type1 is 'type', and typeN is a
* direct subclass of Object. If 'type' is Object, the returned
* string is empty.
* @throws IOException if the bytecode of 'type' or of some of its ancestor
* class cannot be loaded.
*/
private StringBuilder typeAncestors(String type, ClassReader info)
throws IOException
{
StringBuilder b = new StringBuilder();
while (!"java/lang/Object".equals(type)) {
b.append(';').append(type);
type = info.getSuperName();
info = typeInfo(type);
}
return b;
}
/**
* Returns true if the given type implements the given interface.
*
* @param type the internal name of a class or interface.
* @param info the ClassReader corresponding to 'type'.
* @param itf the internal name of a interface.
* @return true if 'type' implements directly or indirectly 'itf'
* @throws IOException if the bytecode of 'type' or of some of its ancestor
* class cannot be loaded.
*/
private boolean typeImplements(String type, ClassReader info, String itf)
throws IOException
{
while (!"java/lang/Object".equals(type)) {
String[] itfs = info.getInterfaces();
for (int i = 0; i < itfs.length; ++i) {
if (itfs[i].equals(itf)) {
return true;
}
}
for (int i = 0; i < itfs.length; ++i) {
if (typeImplements(itfs[i], typeInfo(itfs[i]), itf)) {
return true;
}
}
type = info.getSuperName();
info = typeInfo(type);
}
return false;
}
/**
* Returns a ClassReader corresponding to the given class or interface.
*
* @param type the internal name of a class or interface.
* @return the ClassReader corresponding to 'type'.
* @throws IOException if the bytecode of 'type' cannot be loaded.
*/
private ClassReader typeInfo(final String type) throws IOException {
InputStream is = l.getResourceAsStream(type + ".class");
try {
return new ClassReader(is);
} finally {
is.close();
}
}
}