Java tutorial
/* * eXist Open Source Native XML Database * Copyright (C) 2001-09 Wolfgang M. Meier * wolfgang@exist-db.org * http://exist.sourceforge.net * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program 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 Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * * $Id: GetData.java 9749 2009-08-09 23:18:12Z ixitar $ */ package org.atombeat.xquery.functions.util; import java.io.ByteArrayInputStream; import java.io.IOException; import java.io.InputStream; import javax.xml.parsers.ParserConfigurationException; import javax.xml.parsers.SAXParser; import javax.xml.parsers.SAXParserFactory; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.exist.dom.QName; import org.exist.external.org.apache.commons.io.output.ByteArrayOutputStream; import org.exist.http.servlets.RequestWrapper; import org.exist.memtree.DocumentBuilderReceiver; import org.exist.memtree.MemTreeBuilder; import org.exist.util.MimeTable; import org.exist.util.MimeType; import org.exist.xquery.BasicFunction; import org.exist.xquery.Cardinality; import org.exist.xquery.FunctionSignature; import org.exist.xquery.Variable; import org.exist.xquery.XPathException; import org.exist.xquery.XQueryContext; import org.exist.xquery.functions.request.RequestModule; import org.exist.xquery.value.Base64Binary; import org.exist.xquery.value.FunctionReturnSequenceType; import org.exist.xquery.value.JavaObjectValue; import org.exist.xquery.value.NodeValue; import org.exist.xquery.value.Sequence; import org.exist.xquery.value.StringValue; import org.exist.xquery.value.Type; import org.w3c.dom.Document; import org.xml.sax.InputSource; import org.xml.sax.SAXException; import org.xml.sax.XMLReader; /** * The difference between this and the original are noted with <atombeat> tags. * * @author Wolfgang Meier (wolfgang@exist-db.org) */ public class RequestGetData extends BasicFunction { protected static final Log logger = LogFactory.getLog(RequestGetData.class); public final static FunctionSignature signature = new FunctionSignature( new QName("request-get-data", AtomBeatUtilModule.NAMESPACE_URI, AtomBeatUtilModule.PREFIX), "The same as the eXist request:get-data() function, except hard coded to treat POST content with a content type not in the eXist mime types table as binary rather than XML. (Should be unnecessary after eXist 1.4.1 as there is a switch in the mime-types file.)", null, new FunctionReturnSequenceType(Type.ITEM, Cardinality.ZERO_OR_ONE, "the content of a POST request")); public RequestGetData(XQueryContext context) { super(context, signature); } /* (non-Javadoc) * @see org.exist.xquery.BasicFunction#eval(org.exist.xquery.value.Sequence[], org.exist.xquery.value.Sequence) */ public Sequence eval(Sequence[] args, Sequence contextSequence) throws XPathException { RequestModule myModule = (RequestModule) context.getModule(RequestModule.NAMESPACE_URI); // request object is read from global variable $request Variable var = myModule.resolveVariable(RequestModule.REQUEST_VAR); if (var == null || var.getValue() == null) throw new XPathException(this, "No request object found in the current XQuery context."); if (var.getValue().getItemType() != Type.JAVA_OBJECT) throw new XPathException(this, "Variable $request is not bound to an Java object."); JavaObjectValue value = (JavaObjectValue) var.getValue().itemAt(0); if (value.getObject() instanceof RequestWrapper) { RequestWrapper request = (RequestWrapper) value.getObject(); //if the content length is unknown, return if (request.getContentLength() == -1) { return Sequence.EMPTY_SEQUENCE; } //first, get the content of the request byte[] bufRequestData = null; try { InputStream is = request.getInputStream(); ByteArrayOutputStream bos = new ByteArrayOutputStream(request.getContentLength()); byte[] buf = new byte[256]; int l = 0; while ((l = is.read(buf)) > -1) { bos.write(buf, 0, l); } bufRequestData = bos.toByteArray(); } catch (IOException ioe) { throw new XPathException(this, "An IO exception ocurred: " + ioe.getMessage(), ioe); } //was there any POST content if (bufRequestData != null) { //determine if exists mime database considers this binary data String contentType = request.getContentType(); if (contentType != null) { //strip off any charset encoding info if (contentType.indexOf(";") > -1) contentType = contentType.substring(0, contentType.indexOf(";")); MimeType mimeType = MimeTable.getInstance().getContentType(contentType); //<atombeat> // this code will only encode the request data if the mimeType // is present in the mime table, and the mimeType is stated // as binary... // if(mimeType != null) // { // if(!mimeType.isXMLType()) // { // //binary data // return new Base64Binary(bufRequestData); // } // } // this code takes a more conservative position and assumes that // if the mime type is not present in the table, the request // data should be treated as binary, and should be encoded as // base 64... if (mimeType == null || !mimeType.isXMLType()) { return new Base64Binary(bufRequestData); } //</atombeat> } //try and parse as an XML documemnt, otherwise fallback to returning the data as a string context.pushDocumentContext(); try { //try and construct xml document from input stream, we use eXist's in-memory DOM implementation SAXParserFactory factory = SAXParserFactory.newInstance(); factory.setNamespaceAware(true); //TODO : we should be able to cope with context.getBaseURI() InputSource src = new InputSource(new ByteArrayInputStream(bufRequestData)); SAXParser parser = factory.newSAXParser(); XMLReader reader = parser.getXMLReader(); MemTreeBuilder builder = context.getDocumentBuilder(); DocumentBuilderReceiver receiver = new DocumentBuilderReceiver(builder, true); reader.setContentHandler(receiver); reader.parse(src); Document doc = receiver.getDocument(); return (NodeValue) doc.getDocumentElement(); } catch (ParserConfigurationException e) { //do nothing, we will default to trying to return a string below } catch (SAXException e) { //do nothing, we will default to trying to return a string below } catch (IOException e) { //do nothing, we will default to trying to return a string below } finally { context.popDocumentContext(); } //not a valid XML document, return a string representation of the document String encoding = request.getCharacterEncoding(); if (encoding == null) { encoding = "UTF-8"; } try { String s = new String(bufRequestData, encoding); return new StringValue(s); } catch (IOException e) { throw new XPathException(this, "An IO exception ocurred: " + e.getMessage(), e); } } else { //no post data return Sequence.EMPTY_SEQUENCE; } } else { throw new XPathException(this, "Variable $request is not bound to a Request object."); } } }