/* ==================================================================== 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.poi.openxml4j.opc; import java.io.FilterOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import javax.xml.transform.OutputKeys; import javax.xml.transform.Result; import javax.xml.transform.Transformer; import javax.xml.transform.TransformerException; import javax.xml.transform.dom.DOMSource; import javax.xml.transform.stream.StreamResult; import org.apache.poi.util.IOUtils; import org.apache.poi.util.Internal; import org.apache.poi.util.XMLHelper; import org.w3c.dom.Document; @Internal public final class StreamHelper { private StreamHelper() { // Do nothing } /** * Save the document object in the specified output stream. * * @param xmlContent * The XML document. * @param outStream * The OutputStream in which the XML document will be written. * @return true if the xml is successfully written in the stream, * else false. */ public static boolean saveXmlInStream(Document xmlContent, OutputStream outStream) { try { // https://bz.apache.org/bugzilla/show_bug.cgi?id=67396 xmlContent.setXmlStandalone(true); Transformer trans = XMLHelper.newTransformer(); DOMSource xmlSource = new DOMSource(xmlContent); // prevent close of stream by transformer: Result outputTarget = new StreamResult(new FilterOutputStream( outStream) { @Override public void write(byte[] b, int off, int len) throws IOException { out.write(b, off, len); } @Override public void close() throws IOException { out.flush(); // only flush, don't close! } }); trans.setOutputProperty(OutputKeys.ENCODING, "UTF-8"); // don't indent xml documents, the indent will cause errors in calculating the xml signature // because of different handling of linebreaks in Windows/Unix trans.setOutputProperty(OutputKeys.INDENT, "no"); trans.setOutputProperty(OutputKeys.STANDALONE, "yes"); trans.transform(xmlSource, outputTarget); } catch (TransformerException e) { return false; } return true; } /** * Copy the input stream into the output stream. * * @param inStream * The source stream. * @param outStream * The destination stream. * @return true if the operation succeed, else return false. */ public static boolean copyStream(InputStream inStream, OutputStream outStream) { try { IOUtils.copy(inStream, outStream); return true; } catch (Exception e) { return false; } } }