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	/*
	* Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package javax.sql.rowset.serial;

	import java.io.*;
	import java.lang.reflect.*;
	import java.util.Arrays;
	import java.util.Vector;
	import javax.sql.rowset.RowSetWarning;
	import sun.reflect.CallerSensitive;
	import sun.reflect.Reflection;
	import sun.reflect.misc.ReflectUtil;

	/**
	* A serializable mapping in the Java programming language of an SQL
	* <code>JAVA_OBJECT</code> value. Assuming the Java object
	* implements the <code>Serializable</code> interface, this class simply wraps the
	* serialization process.
	* <P>
	* If however, the serialization is not possible because
	* the Java object is not immediately serializable, this class will
	* attempt to serialize all non-static members to permit the object
	* state to be serialized.
	* Static or transient fields cannot be serialized; an attempt to serialize
	* them will result in a <code>SerialException</code> object being thrown.
	*
	* <h3> Thread safety </h3>
	*
	* A SerialJavaObject is not safe for use by multiple concurrent threads. If a
	* SerialJavaObject is to be used by more than one thread then access to the
	* SerialJavaObject should be controlled by appropriate synchronization.
	*
	* @author Jonathan Bruce
	*/
	public class SerialJavaObject implements Serializable, Cloneable {

	/**
	* Placeholder for object to be serialized.
	*/
	private Object obj;


	/**
	* Placeholder for all fields in the <code>JavaObject</code> being serialized.
	*/
	private transient Field[] fields;

	/**
	* Constructor for <code>SerialJavaObject</code> helper class.
	* <p>
	*
	* @param obj the Java <code>Object</code> to be serialized
	* @throws SerialException if the object is found not to be serializable
	*/
	public SerialJavaObject(Object obj) throws SerialException {

	// if any static fields are found, an exception
	// should be thrown


	// get Class. Object instance should always be available
	Class<?> c = obj.getClass();

	// determine if object implements Serializable i/f
	if (!(obj instanceof java.io.Serializable)) {
	setWarning(new RowSetWarning("Warning, the object passed to the constructor does not implement Serializable"));
	}

	// can only determine public fields (obviously). If
	// any of these are static, this should invalidate
	// the action of attempting to persist these fields
	// in a serialized form
	fields = c.getFields();

	if (hasStaticFields(fields)) {
	throw new SerialException("Located static fields in " +
	"object instance. Cannot serialize");
	}

	this.obj = obj;
	}

	/**
	* Returns an <code>Object</code> that is a copy of this <code>SerialJavaObject</code>
	* object.
	*
	* @return a copy of this <code>SerialJavaObject</code> object as an
	* <code>Object</code> in the Java programming language
	* @throws SerialException if the instance is corrupt
	*/
	public Object getObject() throws SerialException {
	return this.obj;
	}

	/**
	* Returns an array of <code>Field</code> objects that contains each
	* field of the object that this helper class is serializing.
	*
	* @return an array of <code>Field</code> objects
	* @throws SerialException if an error is encountered accessing
	* the serialized object
	* @throws SecurityException If a security manager, <i>s</i>, is present
	* and the caller's class loader is not the same as or an
	* ancestor of the class loader for the class of the
	* {@linkplain #getObject object} being serialized
	* and invocation of {@link SecurityManager#checkPackageAccess
	* s.checkPackageAccess()} denies access to the package
	* of that class.
	* @see Class#getFields
	*/
	@CallerSensitive
	public Field[] getFields() throws SerialException {
	if (fields != null) {
	Class<?> c = this.obj.getClass();
	SecurityManager sm = System.getSecurityManager();
	if (sm != null) {
	/*
	* Check if the caller is allowed to access the specified class's package.
	* If access is denied, throw a SecurityException.
	*/
	Class<?> caller = sun.reflect.Reflection.getCallerClass();
	if (ReflectUtil.needsPackageAccessCheck(caller.getClassLoader(),
	c.getClassLoader())) {
	ReflectUtil.checkPackageAccess(c);
	}
	}
	return c.getFields();
	} else {
	throw new SerialException("SerialJavaObject does not contain" +
	" a serialized object instance");
	}
	}

	/**
	* The identifier that assists in the serialization of this
	* <code>SerialJavaObject</code> object.
	*/
	static final long serialVersionUID = -1465795139032831023L;

	/**
	* A container for the warnings issued on this <code>SerialJavaObject</code>
	* object. When there are multiple warnings, each warning is chained to the
	* previous warning.
	*/
	Vector<RowSetWarning> chain;

	/**
	* Compares this SerialJavaObject to the specified object.
	* The result is {@code true} if and only if the argument
	* is not {@code null} and is a {@code SerialJavaObject}
	* object that is identical to this object
	*
	* @param o The object to compare this {@code SerialJavaObject} against
	*
	* @return {@code true} if the given object represents a {@code SerialJavaObject}
	* equivalent to this SerialJavaObject, {@code false} otherwise
	*
	*/
	public boolean equals(Object o) {
	if (this == o) {
	return true;
	}
	if (o instanceof SerialJavaObject) {
	SerialJavaObject sjo = (SerialJavaObject) o;
	return obj.equals(sjo.obj);
	}
	return false;
	}

	/**
	* Returns a hash code for this SerialJavaObject. The hash code for a
	* {@code SerialJavaObject} object is taken as the hash code of
	* the {@code Object} it stores
	*
	* @return a hash code value for this object.
	*/
	public int hashCode() {
	return 31 + obj.hashCode();
	}

	/**
	* Returns a clone of this {@code SerialJavaObject}.
	*
	* @return a clone of this SerialJavaObject
	*/

	public Object clone() {
	try {
	SerialJavaObject sjo = (SerialJavaObject) super.clone();
	sjo.fields = Arrays.copyOf(fields, fields.length);
	if (chain != null)
	sjo.chain = new Vector<>(chain);
	return sjo;
	} catch (CloneNotSupportedException ex) {
	// this shouldn't happen, since we are Cloneable
	throw new InternalError();
	}
	}

	/**
	* Registers the given warning.
	*/
	private void setWarning(RowSetWarning e) {
	if (chain == null) {
	chain = new Vector<>();
	}
	chain.add(e);
	}

	/**
	* readObject is called to restore the state of the {@code SerialJavaObject}
	* from a stream.
	*/
	private void readObject(ObjectInputStream s)
	throws IOException, ClassNotFoundException {

	ObjectInputStream.GetField fields1 = s.readFields();
	@SuppressWarnings("unchecked")
	Vector<RowSetWarning> tmp = (Vector<RowSetWarning>)fields1.get("chain", null);
	if (tmp != null)
	chain = new Vector<>(tmp);

	obj = fields1.get("obj", null);
	if (obj != null) {
	fields = obj.getClass().getFields();
	if(hasStaticFields(fields))
	throw new IOException("Located static fields in " +
	"object instance. Cannot serialize");
	} else {
	throw new IOException("Object cannot be null!");
	}

	}

	/**
	* writeObject is called to save the state of the {@code SerialJavaObject}
	* to a stream.
	*/
	private void writeObject(ObjectOutputStream s)
	throws IOException {
	ObjectOutputStream.PutField fields = s.putFields();
	fields.put("obj", obj);
	fields.put("chain", chain);
	s.writeFields();
	}

	/*
	* Check to see if there are any Static Fields in this object
	*/
	private static boolean hasStaticFields(Field[] fields) {
	for (Field field : fields) {
	if ( field.getModifiers() == Modifier.STATIC) {
	return true;
	}
	}
	return false;
	}
	}

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