/* * 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.jempbox.impl; import java.io.File; import java.io.InputStream; import java.io.IOException; import java.io.OutputStream; import java.io.UnsupportedEncodingException; import java.io.StringWriter; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.transform.OutputKeys; import javax.xml.transform.Result; import javax.xml.transform.Transformer; import javax.xml.transform.TransformerException; import javax.xml.transform.TransformerFactory; import javax.xml.transform.dom.DOMSource; import javax.xml.transform.stream.StreamResult; import org.apache.jempbox.xmp.Elementable; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.Node; import org.w3c.dom.NodeList; import org.w3c.dom.Text; import org.xml.sax.InputSource; /** * This class with handle some simple XML operations. * * @author <a href="mailto:ben@benlitchfield.com">Ben Litchfield</a> * @author <a href="mailto:chris@oezbek.net">Christopher Oezbek</a> * * @version $Revision: 1.4 $ */ public class XMLUtil { /** * Utility class, should not be instantiated. * */ private XMLUtil() { } /** * This will parse an XML stream and create a DOM document. * * @param is The stream to get the XML from. * @return The DOM document. * @throws IOException It there is an error creating the dom. */ public static Document parse( InputStream is ) throws IOException { try { DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance(); DocumentBuilder builder = builderFactory.newDocumentBuilder(); return builder.parse( is ); } catch( Exception e ) { IOException thrown = new IOException( e.getMessage() ); throw thrown; } } /** * This will parse an InputSource and create a DOM document. * * @param is The stream to get the XML from. * @return The DOM document. * @throws IOException It there is an error creating the dom. */ public static Document parse( InputSource is ) throws IOException { try { DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance(); DocumentBuilder builder = builderFactory.newDocumentBuilder(); return builder.parse( is ); } catch( Exception e ) { IOException thrown = new IOException( e.getMessage() ); throw thrown; } } /** * This will parse an XML stream and create a DOM document. * * @param fileName The file to get the XML from. * @return The DOM document. * @throws IOException It there is an error creating the dom. */ public static Document parse( String fileName ) throws IOException { try { DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance(); DocumentBuilder builder = builderFactory.newDocumentBuilder(); return builder.parse( fileName ); } catch( Exception e ) { IOException thrown = new IOException( e.getMessage() ); throw thrown; } } /** * Create a new blank XML document. * * @return The new blank XML document. * * @throws IOException If there is an error creating the XML document. */ public static Document newDocument() throws IOException { try { DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance(); DocumentBuilder builder = builderFactory.newDocumentBuilder(); return builder.newDocument(); } catch( Exception e ) { IOException thrown = new IOException( e.getMessage() ); throw thrown; } } /** * Get the first instance of an element by name. * * @param parent The parent to get the element from. * @param elementName The name of the element to look for. * @return The element or null if it is not found. */ public static Element getElement( Element parent, String elementName ) { Element retval = null; NodeList children = parent.getElementsByTagName( elementName ); if( children.getLength() > 0 ) { retval = (Element)children.item( 0 ); } return retval; } /** * Get the integer value of a subnode. * * @param parent The parent element that holds the values. * @param nodeName The name of the node that holds the integer value. * * @return The integer value of the node. */ public static Integer getIntValue( Element parent, String nodeName ) { String intVal = XMLUtil.getStringValue( XMLUtil.getElement( parent, nodeName ) ); Integer retval = null; if( intVal != null ) { retval = new Integer( intVal ); } return retval; } /** * Set the integer value of an element. * * @param parent The parent element that will hold this subelement. * @param nodeName The name of the subelement. * @param intValue The value to set. */ public static void setIntValue( Element parent, String nodeName, Integer intValue ) { Element currentValue = getElement( parent, nodeName ); if( intValue == null ) { if( currentValue != null ) { parent.removeChild( currentValue ); } else { //it doesn't exist so we don't need to remove it. } } else { if( currentValue == null ) { currentValue = parent.getOwnerDocument().createElement( nodeName ); parent.appendChild( currentValue ); } XMLUtil.setStringValue( currentValue, intValue.toString() ); } } /** * Get the value of a subnode. * * @param parent The parent element that holds the values. * @param nodeName The name of the node that holds the value. * * @return The value of the sub node. */ public static String getStringValue( Element parent, String nodeName ) { return XMLUtil.getStringValue( XMLUtil.getElement( parent, nodeName ) ); } /** * Set the value of an element. * * @param parent The parent element that will hold this subelement. * @param nodeName The name of the subelement. * @param nodeValue The value to set. */ public static void setStringValue( Element parent, String nodeName, String nodeValue ) { Element currentValue = getElement( parent, nodeName ); if( nodeValue == null ) { if( currentValue != null ) { parent.removeChild( currentValue ); } else { //it doesn't exist so we don't need to remove it. } } else { if( currentValue == null ) { currentValue = parent.getOwnerDocument().createElement( nodeName ); parent.appendChild( currentValue ); } XMLUtil.setStringValue( currentValue, nodeValue ); } } /** * This will get the text value of an element. * * @param node The node to get the text value for. * @return The text of the node. */ public static String getStringValue( Element node ) { String retval = ""; NodeList children = node.getChildNodes(); for( int i=0; i<children.getLength(); i++ ) { Node next = children.item( i ); if( next instanceof Text ) { retval = next.getNodeValue(); } } return retval; } /** * This will set the text value of an element. * * @param node The node to get the text value for. * @param value The new value to set the node to. */ public static void setStringValue( Element node, String value ) { NodeList children = node.getChildNodes(); for( int i=0; i<children.getLength(); i++ ) { Node next = children.item( i ); if( next instanceof Text ) { node.removeChild( next ); } } node.appendChild( node.getOwnerDocument().createTextNode( value ) ); } /** * Set an XML element document. * * @param parent The parent document to set the value in. * @param name The name of the XML element to set. * @param node The node to set or clear. */ public static void setElementableValue( Element parent, String name, Elementable node ) { NodeList nodes = parent.getElementsByTagName( name ); if( node == null ) { for( int i=0; i<nodes.getLength(); i++ ) { parent.removeChild( nodes.item( i ) ); } } else { if( nodes.getLength() == 0 ) { if( parent.hasChildNodes() ) { Node firstChild = parent.getChildNodes().item( 0 ); parent.insertBefore( node.getElement(), firstChild ); } else { parent.appendChild( node.getElement() ); } } else { Node oldNode = nodes.item( 0 ); parent.replaceChild( node.getElement(), oldNode ); } } } /** * Save the XML document to a file. * * @param doc The XML document to save. * @param file The file to save the document to. * @param encoding The encoding to save the file as. * * @throws TransformerException If there is an error while saving the XML. */ public static void save( Document doc, String file, String encoding ) throws TransformerException { try { Transformer transformer = TransformerFactory.newInstance().newTransformer(); transformer.setOutputProperty(OutputKeys.INDENT, "yes"); transformer.setOutputProperty(OutputKeys.ENCODING, encoding); transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes"); // initialize StreamResult with File object to save to file Result result = new StreamResult(new File(file)); DOMSource source = new DOMSource(doc); transformer.transform(source, result); } finally { } } /** * Save the XML document to an output stream. * * @param doc The XML document to save. * @param outStream The stream to save the document to. * @param encoding The encoding to save the file as. * * @throws TransformerException If there is an error while saving the XML. */ public static void save( Node doc, OutputStream outStream, String encoding ) throws TransformerException { try { Transformer transformer = TransformerFactory.newInstance().newTransformer(); transformer.setOutputProperty(OutputKeys.INDENT, "yes"); transformer.setOutputProperty(OutputKeys.ENCODING, encoding); transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes"); // initialize StreamResult with File object to save to file Result result = new StreamResult(outStream); DOMSource source = new DOMSource(doc); transformer.transform(source, result); } finally { } } /** * Convert the document to an array of bytes. * * @param doc The XML document. * @param encoding The encoding of the output data. * * @return The XML document as an array of bytes. * * @throws TransformerException If there is an error transforming to text. */ public static byte[] asByteArray( Document doc, String encoding) throws TransformerException { Transformer transformer = TransformerFactory.newInstance().newTransformer(); transformer.setOutputProperty(OutputKeys.INDENT, "yes"); transformer.setOutputProperty(OutputKeys.ENCODING, encoding); transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes"); StringWriter writer = new StringWriter(); Result result = new StreamResult(writer); DOMSource source = new DOMSource(doc); transformer.transform(source, result); try { return writer.getBuffer().toString().getBytes(encoding); } catch (UnsupportedEncodingException e) { throw new TransformerException("Unsupported Encoding", e); } } }