Back to index...

	/*
	* Copyright (c) 2008, 2012, 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 com.sun.beans.decoder;

	import com.sun.beans.finder.ClassFinder;

	import java.beans.ExceptionListener;

	import java.io.IOException;
	import java.io.StringReader;

	import java.lang.ref.Reference;
	import java.lang.ref.WeakReference;

	import java.util.ArrayList;
	import java.util.HashMap;
	import java.util.List;
	import java.util.Map;
	import java.security.AccessControlContext;
	import java.security.AccessController;
	import java.security.PrivilegedAction;

	import javax.xml.parsers.ParserConfigurationException;
	import javax.xml.parsers.SAXParserFactory;

	import org.xml.sax.Attributes;
	import org.xml.sax.InputSource;
	import org.xml.sax.SAXException;
	import org.xml.sax.helpers.DefaultHandler;

	import sun.misc.SharedSecrets;

	/**
	* The main class to parse JavaBeans XML archive.
	*
	* @since 1.7
	*
	* @author Sergey A. Malenkov
	*
	* @see ElementHandler
	*/
	public final class DocumentHandler extends DefaultHandler {
	private final AccessControlContext acc = AccessController.getContext();
	private final Map<String, Class<? extends ElementHandler>> handlers = new HashMap<>();
	private final Map<String, Object> environment = new HashMap<>();
	private final List<Object> objects = new ArrayList<>();

	private Reference<ClassLoader> loader;
	private ExceptionListener listener;
	private Object owner;

	private ElementHandler handler;

	/**
	* Creates new instance of document handler.
	*/
	public DocumentHandler() {
	setElementHandler("java", JavaElementHandler.class); // NON-NLS: the element name
	setElementHandler("null", NullElementHandler.class); // NON-NLS: the element name
	setElementHandler("array", ArrayElementHandler.class); // NON-NLS: the element name
	setElementHandler("class", ClassElementHandler.class); // NON-NLS: the element name
	setElementHandler("string", StringElementHandler.class); // NON-NLS: the element name
	setElementHandler("object", ObjectElementHandler.class); // NON-NLS: the element name

	setElementHandler("void", VoidElementHandler.class); // NON-NLS: the element name
	setElementHandler("char", CharElementHandler.class); // NON-NLS: the element name
	setElementHandler("byte", ByteElementHandler.class); // NON-NLS: the element name
	setElementHandler("short", ShortElementHandler.class); // NON-NLS: the element name
	setElementHandler("int", IntElementHandler.class); // NON-NLS: the element name
	setElementHandler("long", LongElementHandler.class); // NON-NLS: the element name
	setElementHandler("float", FloatElementHandler.class); // NON-NLS: the element name
	setElementHandler("double", DoubleElementHandler.class); // NON-NLS: the element name
	setElementHandler("boolean", BooleanElementHandler.class); // NON-NLS: the element name

	// some handlers for new elements
	setElementHandler("new", NewElementHandler.class); // NON-NLS: the element name
	setElementHandler("var", VarElementHandler.class); // NON-NLS: the element name
	setElementHandler("true", TrueElementHandler.class); // NON-NLS: the element name
	setElementHandler("false", FalseElementHandler.class); // NON-NLS: the element name
	setElementHandler("field", FieldElementHandler.class); // NON-NLS: the element name
	setElementHandler("method", MethodElementHandler.class); // NON-NLS: the element name
	setElementHandler("property", PropertyElementHandler.class); // NON-NLS: the element name
	}

	/**
	* Returns the class loader used to instantiate objects.
	* If the class loader has not been explicitly set
	* then {@code null} is returned.
	*
	* @return the class loader used to instantiate objects
	*/
	public ClassLoader getClassLoader() {
	return (this.loader != null)
	? this.loader.get()
	: null;
	}

	/**
	* Sets the class loader used to instantiate objects.
	* If the class loader is not set
	* then default class loader will be used.
	*
	* @param loader a classloader to use
	*/
	public void setClassLoader(ClassLoader loader) {
	this.loader = new WeakReference<ClassLoader>(loader);
	}

	/**
	* Returns the exception listener for parsing.
	* The exception listener is notified
	* when handler catches recoverable exceptions.
	* If the exception listener has not been explicitly set
	* then default exception listener is returned.
	*
	* @return the exception listener for parsing
	*/
	public ExceptionListener getExceptionListener() {
	return this.listener;
	}

	/**
	* Sets the exception listener for parsing.
	* The exception listener is notified
	* when handler catches recoverable exceptions.
	*
	* @param listener the exception listener for parsing
	*/
	public void setExceptionListener(ExceptionListener listener) {
	this.listener = listener;
	}

	/**
	* Returns the owner of this document handler.
	*
	* @return the owner of this document handler
	*/
	public Object getOwner() {
	return this.owner;
	}

	/**
	* Sets the owner of this document handler.
	*
	* @param owner the owner of this document handler
	*/
	public void setOwner(Object owner) {
	this.owner = owner;
	}

	/**
	* Returns the handler for the element with specified name.
	*
	* @param name the name of the element
	* @return the corresponding element handler
	*/
	public Class<? extends ElementHandler> getElementHandler(String name) {
	Class<? extends ElementHandler> type = this.handlers.get(name);
	if (type == null) {
	throw new IllegalArgumentException("Unsupported element: " + name);
	}
	return type;
	}

	/**
	* Sets the handler for the element with specified name.
	*
	* @param name the name of the element
	* @param handler the corresponding element handler
	*/
	public void setElementHandler(String name, Class<? extends ElementHandler> handler) {
	this.handlers.put(name, handler);
	}

	/**
	* Indicates whether the variable with specified identifier is defined.
	*
	* @param id the identifier
	* @return @{code true} if the variable is defined;
	* @{code false} otherwise
	*/
	public boolean hasVariable(String id) {
	return this.environment.containsKey(id);
	}

	/**
	* Returns the value of the variable with specified identifier.
	*
	* @param id the identifier
	* @return the value of the variable
	*/
	public Object getVariable(String id) {
	if (!this.environment.containsKey(id)) {
	throw new IllegalArgumentException("Unbound variable: " + id);
	}
	return this.environment.get(id);
	}

	/**
	* Sets new value of the variable with specified identifier.
	*
	* @param id the identifier
	* @param value new value of the variable
	*/
	public void setVariable(String id, Object value) {
	this.environment.put(id, value);
	}

	/**
	* Returns the array of readed objects.
	*
	* @return the array of readed objects
	*/
	public Object[] getObjects() {
	return this.objects.toArray();
	}

	/**
	* Adds the object to the list of readed objects.
	*
	* @param object the object that is readed from XML document
	*/
	void addObject(Object object) {
	this.objects.add(object);
	}

	/**
	* Disables any external entities.
	*/
	@Override
	public InputSource resolveEntity(String publicId, String systemId) {
	return new InputSource(new StringReader(""));
	}

	/**
	* Prepares this handler to read objects from XML document.
	*/
	@Override
	public void startDocument() {
	this.objects.clear();
	this.handler = null;
	}

	/**
	* Parses opening tag of XML element
	* using corresponding element handler.
	*
	* @param uri the namespace URI, or the empty string
	* if the element has no namespace URI or
	* if namespace processing is not being performed
	* @param localName the local name (without prefix), or the empty string
	* if namespace processing is not being performed
	* @param qName the qualified name (with prefix), or the empty string
	* if qualified names are not available
	* @param attributes the attributes attached to the element
	*/
	@Override
	public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
	ElementHandler parent = this.handler;
	try {
	this.handler = getElementHandler(qName).newInstance();
	this.handler.setOwner(this);
	this.handler.setParent(parent);
	}
	catch (Exception exception) {
	throw new SAXException(exception);
	}
	for (int i = 0; i < attributes.getLength(); i++)
	try {
	String name = attributes.getQName(i);
	String value = attributes.getValue(i);
	this.handler.addAttribute(name, value);
	}
	catch (RuntimeException exception) {
	handleException(exception);
	}

	this.handler.startElement();
	}

	/**
	* Parses closing tag of XML element
	* using corresponding element handler.
	*
	* @param uri the namespace URI, or the empty string
	* if the element has no namespace URI or
	* if namespace processing is not being performed
	* @param localName the local name (without prefix), or the empty string
	* if namespace processing is not being performed
	* @param qName the qualified name (with prefix), or the empty string
	* if qualified names are not available
	*/
	@Override
	public void endElement(String uri, String localName, String qName) {
	try {
	this.handler.endElement();
	}
	catch (RuntimeException exception) {
	handleException(exception);
	}
	finally {
	this.handler = this.handler.getParent();
	}
	}

	/**
	* Parses character data inside XML element.
	*
	* @param chars the array of characters
	* @param start the start position in the character array
	* @param length the number of characters to use
	*/
	@Override
	public void characters(char[] chars, int start, int length) {
	if (this.handler != null) {
	try {
	while (0 < length--) {
	this.handler.addCharacter(chars[start++]);
	}
	}
	catch (RuntimeException exception) {
	handleException(exception);
	}
	}
	}

	/**
	* Handles an exception using current exception listener.
	*
	* @param exception an exception to handle
	* @see #setExceptionListener
	*/
	public void handleException(Exception exception) {
	if (this.listener == null) {
	throw new IllegalStateException(exception);
	}
	this.listener.exceptionThrown(exception);
	}

	/**
	* Starts parsing of the specified input source.
	*
	* @param input the input source to parse
	*/
	public void parse(final InputSource input) {
	if ((this.acc == null) && (null != System.getSecurityManager())) {
	throw new SecurityException("AccessControlContext is not set");
	}
	AccessControlContext stack = AccessController.getContext();
	SharedSecrets.getJavaSecurityAccess().doIntersectionPrivilege(new PrivilegedAction<Void>() {
	public Void run() {
	try {
	SAXParserFactory.newInstance().newSAXParser().parse(input, DocumentHandler.this);
	}
	catch (ParserConfigurationException exception) {
	handleException(exception);
	}
	catch (SAXException wrapper) {
	Exception exception = wrapper.getException();
	if (exception == null) {
	exception = wrapper;
	}
	handleException(exception);
	}
	catch (IOException exception) {
	handleException(exception);
	}
	return null;
	}
	}, stack, this.acc);
	}

	/**
	* Resolves class by name using current class loader.
	* This method handles exception using current exception listener.
	*
	* @param name the name of the class
	* @return the object that represents the class
	*/
	public Class<?> findClass(String name) {
	try {
	return ClassFinder.resolveClass(name, getClassLoader());
	}
	catch (ClassNotFoundException exception) {
	handleException(exception);
	return null;
	}
	}
	}

Back to index...