org.apache.openjpa.util.Serialization Maven / Gradle / Ivy
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* 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.util;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.ObjectStreamClass;
import java.io.OutputStream;
import java.io.Serializable;
import java.security.AccessController;
import java.security.PrivilegedAction;
import org.apache.openjpa.conf.OpenJPAConfiguration;
import org.apache.openjpa.kernel.StoreContext;
import org.apache.openjpa.lib.log.Log;
import org.apache.openjpa.lib.util.J2DoPrivHelper;
import org.apache.openjpa.lib.util.Localizer;
import org.apache.openjpa.lib.util.MultiClassLoader;
/**
* Helper class to serialize and deserialize persistent objects,
* subtituting oids into the serialized stream and subtituting the persistent
* objects back during deserialization.
*
* @author Abe White
* @since 0.3.3
* @nojavadoc
*/
public class Serialization {
private static final Localizer _loc = Localizer.forPackage
(Serialization.class);
/**
* Serialize a value that might contain persistent objects. Replaces
* persistent objects with their oids.
*/
public static byte[] serialize(Object val, StoreContext ctx) {
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
try {
ObjectOutputStream objs = new PersistentObjectOutputStream(bytes,
ctx);
objs.writeObject(val);
objs.flush();
return bytes.toByteArray();
} catch (Exception e) {
throw new StoreException(e);
}
}
/**
* Deserialize an object value from the given bytes.
*/
public static Object deserialize(byte[] bytes, StoreContext ctx) {
ByteArrayInputStream in = new ByteArrayInputStream(bytes);
return deserialize(in, ctx);
}
/**
* Deserialize an object value from the given stream.
*/
public static Object deserialize(InputStream in, StoreContext ctx) {
try {
if (ctx == null)
return new ClassResolvingObjectInputStream(in).readObject();
return new PersistentObjectInputStream(in, ctx).readObject();
} catch (Exception e) {
throw new StoreException(e);
}
}
/**
* Object output stream that replaces persistent objects with their oids.
*/
public static class PersistentObjectOutputStream
extends ObjectOutputStream {
private StoreContext _ctx;
/**
* Constructor; supply underlying stream.
*/
public PersistentObjectOutputStream(OutputStream delegate,
StoreContext ctx)
throws IOException {
super(delegate);
_ctx = ctx;
AccessController.doPrivileged(new PrivilegedAction() {
public Object run() {
enableReplaceObject(true);
return null;
}
});
}
protected Object replaceObject(Object obj) {
Object oid = _ctx.getObjectId(obj);
return (oid == null) ? obj : new ObjectIdMarker(oid);
}
}
public static class ClassResolvingObjectInputStream
extends ObjectInputStream {
public ClassResolvingObjectInputStream(InputStream delegate)
throws IOException {
super(delegate);
}
protected Class resolveClass(ObjectStreamClass desc)
throws IOException, ClassNotFoundException {
MultiClassLoader loader = AccessController
.doPrivileged(J2DoPrivHelper.newMultiClassLoaderAction());
addContextClassLoaders(loader);
loader.addClassLoader(getClass().getClassLoader());
loader.addClassLoader(MultiClassLoader.SYSTEM_LOADER);
return Class.forName(desc.getName(), true, loader);
}
protected void addContextClassLoaders(MultiClassLoader loader) {
loader.addClassLoader(AccessController.doPrivileged(
J2DoPrivHelper.getContextClassLoaderAction()));
}
}
/**
* Object input stream that replaces oids with their objects.
*/
public static class PersistentObjectInputStream
extends ClassResolvingObjectInputStream {
private final StoreContext _ctx;
/**
* Constructor; supply source stream and broker to
* use for persistent object lookups.
*/
public PersistentObjectInputStream(InputStream delegate,
StoreContext ctx)
throws IOException {
super(delegate);
_ctx = ctx;
AccessController.doPrivileged(new PrivilegedAction() {
public Object run() {
enableResolveObject(true);
return null;
}
});
}
protected void addContextClassLoaders(MultiClassLoader loader) {
super.addContextClassLoaders(loader);
loader.addClassLoader(_ctx.getClassLoader());
}
protected Object resolveObject(Object obj) {
if (!(obj instanceof ObjectIdMarker))
return obj;
Object oid = ((ObjectIdMarker) obj).oid;
if (oid == null)
return null;
Object pc = _ctx.find(oid, null, null, null, 0);
if (pc == null) {
Log log = _ctx.getConfiguration().getLog
(OpenJPAConfiguration.LOG_RUNTIME);
if (log.isWarnEnabled())
log.warn(_loc.get("bad-ser-oid", oid));
if (log.isTraceEnabled())
log.trace(new ObjectNotFoundException(oid));
}
return pc;
}
}
/**
* Marker for oids.
*/
private static class ObjectIdMarker
implements Serializable {
public Object oid;
public ObjectIdMarker(Object oid) {
this.oid = oid;
}
}
}