com.sun.tools.xjc.runtime.JAXBContextFactory Maven / Gradle / Ivy
/*
* Copyright (c) 1997, 2022 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Distribution License v. 1.0, which is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
package com.sun.tools.xjc.runtime;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.StringTokenizer;
import jakarta.xml.bind.JAXBContext;
import jakarta.xml.bind.JAXBException;
/**
* This class implements the actual logic of {@link JAXBContext#newInstance}.
*
*
* This class works as a facade and all the actual work is delegated to
* a JAXB provider that happens to be in the runtime (not necessarily the JAXB RI.)
* This allows the generated code to be run with any JAXB provider.
*
*
* This code is only used when XJC generates interfaces/implementations.
*
*
* The trick to make this work is two ObjectFactory classes that we generate
* in the interface/implementation mode.
*
*
* The public ObjectFactory follows the spec, and this is the one that's exposed
* to users. The public ObjectFactory refers to interfaces, so they aren't
* directly usable by a JAXB 2.0 implementation.
*
*
* The private one lives in the impl package, and this one is indistinguishable
* from the ObjectFactory that we generate for the value class generation mode.
* This private ObjectFactory refers to implementation classes, which are
* also indistinguishable from value classes that JAXB generates.
*
*
* All in all, the private ObjectFactory plus implementation classes give
* a JAXB provider an illusion that they are dealing with value classes
* that happens to implement some interfaces.
*
*
* In this way, the JAXB RI can provide the portability even for the
* interface/implementation generation mode.
*
* @since 2.0
* @author Kohsuke Kawaguchi
*/
public class JAXBContextFactory {
private static final String DOT_OBJECT_FACTORY = ".ObjectFactory";
private static final String IMPL_DOT_OBJECT_FACTORY = ".impl.ObjectFactory";
/**
* The JAXB API will invoke this method via reflection
*/
public static JAXBContext createContext( Class[] classes, Map properties ) throws JAXBException {
Class[] r = new Class[classes.length];
boolean modified = false;
// find any reference to our 'public' ObjectFactory and
// replace that to our 'private' ObjectFactory.
for( int i=0; i c = classes[i];
String name = c.getName();
if(name.endsWith(DOT_OBJECT_FACTORY)
&& !name.endsWith(IMPL_DOT_OBJECT_FACTORY)) {
// we never generate into the root package, so no need to worry about FQCN "ObjectFactory"
// if we find one, tell the real JAXB provider to
// load foo.bar.impl.ObjectFactory
name = name.substring(0,name.length()-DOT_OBJECT_FACTORY.length())+IMPL_DOT_OBJECT_FACTORY;
try {
c = getClassClassLoader(c).loadClass(name);
} catch (ClassNotFoundException e) {
throw new JAXBException(e);
}
modified = true;
}
r[i] = c;
}
if(!modified) {
// if the class list doesn't contain any of our classes,
// this ContextFactory shouldn't have been called in the first place
// if we simply continue, we'll just end up with the infinite recursion.
// the only case that I can think of where this could happen is
// when the user puts additional classes into the JAXB-generated
// package and pass them to JAXBContext.newInstance().
// Under normal use, this shouldn't happen.
// anyway, bail out now.
// if you hit this problem and wondering how to get around the problem,
// subscribe and send a note to [email protected] (http://jaxb.dev.java.net/)
throw new JAXBException("Unable to find a JAXB implementation to delegate");
}
// delegate to the JAXB provider in the system
return JAXBContext.newInstance(r,properties);
}
/**
* The JAXB API will invoke this method via reflection
*/
public static JAXBContext createContext( String contextPath,
ClassLoader classLoader, Map properties ) throws JAXBException {
List> classes = new ArrayList<>();
StringTokenizer tokens = new StringTokenizer(contextPath,":");
// each package should be pointing to a JAXB RI generated
// content interface package.
//
// translate them into a list of private ObjectFactories.
try {
while(tokens.hasMoreTokens()) {
String pkg = tokens.nextToken();
classes.add(classLoader.loadClass(pkg+IMPL_DOT_OBJECT_FACTORY));
}
} catch (ClassNotFoundException e) {
throw new JAXBException(e);
}
// delegate to the JAXB provider in the system
return JAXBContext.newInstance(classes.toArray(new Class[0]),properties);
}
private static ClassLoader getClassClassLoader(final Class c) {
if (System.getSecurityManager() == null) {
return c.getClassLoader();
} else {
return java.security.AccessController.doPrivileged(
new java.security.PrivilegedAction<>() {
@Override
public ClassLoader run() {
return c.getClassLoader();
}
});
}
}
}