Java tutorial
/** * Copyright (c) 2005-2010, WSO2 Inc. (http://www.wso2.org) All Rights Reserved. * * WSO2 Inc. 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.synapse.commons.json; import org.apache.axiom.om.OMDataSource; import org.apache.axiom.om.OMException; import org.apache.axiom.om.OMOutputFormat; import org.apache.commons.io.IOUtils; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import javax.xml.stream.XMLStreamConstants; import javax.xml.stream.XMLStreamException; import javax.xml.stream.XMLStreamReader; import javax.xml.stream.XMLStreamWriter; import java.io.*; final class JsonDataSource implements OMDataSource { private static final Log logger = LogFactory.getLog(JsonDataSourceImpl.class.getName()); private final InputStream inputStream; public JsonDataSource(InputStream inputStream) { if (inputStream instanceof BufferedInputStream) { this.inputStream = inputStream; // and we assume that this passed in input stream is fresh and it has been marked first. } else if (inputStream != null) { this.inputStream = new BufferedInputStream(inputStream); this.inputStream.mark(Integer.MAX_VALUE); } else { this.inputStream = null; logger.error("#JsonDataSource. Created invalid JSON DataSource. No JSON input stream found."); } } public void serialize(OutputStream output, OMOutputFormat format) throws XMLStreamException { try { if (format != null && format.getContentType() != null) { if (format.getContentType().contains("xml")) { inputStream.reset(); // reuse the stream JsonUtil.toXml(inputStream, false).serialize(output, format); return; } } inputStream.reset(); IOUtils.copy(inputStream, output); } catch (IOException e) { logger.error("#serialize:OutputStream. Could not serialize JSON payload. Error>>> " + e.getLocalizedMessage()); throw new OMException("Could not serialize JSON payload.", e); } } public void serialize(Writer writer, OMOutputFormat format) throws XMLStreamException { try { if (format != null && format.getContentType() != null) { if (format.getContentType().contains("xml")) { inputStream.reset(); // reuse the stream JsonUtil.toXml(inputStream, false).serialize(writer, format); return; } } inputStream.reset(); IOUtils.copy(inputStream, writer); } catch (IOException e) { logger.error( "#serialize:Writer. Could not serialize JSON payload. Error>>> " + e.getLocalizedMessage()); throw new OMException("Could not serialize JSON payload.", e); } } public void serialize(XMLStreamWriter xmlWriter) throws XMLStreamException { XMLStreamReader reader = getReader(); xmlWriter.writeStartDocument(); while (reader.hasNext()) { int x = reader.next(); switch (x) { case XMLStreamConstants.START_ELEMENT: xmlWriter.writeStartElement(reader.getPrefix(), reader.getLocalName(), reader.getNamespaceURI()); int namespaceCount = reader.getNamespaceCount(); for (int i = namespaceCount - 1; i >= 0; i--) { xmlWriter.writeNamespace(reader.getNamespacePrefix(i), reader.getNamespaceURI(i)); } int attributeCount = reader.getAttributeCount(); for (int i = 0; i < attributeCount; i++) { xmlWriter.writeAttribute(reader.getAttributePrefix(i), reader.getAttributeNamespace(i), reader.getAttributeLocalName(i), reader.getAttributeValue(i)); } break; case XMLStreamConstants.START_DOCUMENT: break; case XMLStreamConstants.CHARACTERS: xmlWriter.writeCharacters(reader.getText()); break; case XMLStreamConstants.CDATA: xmlWriter.writeCData(reader.getText()); break; case XMLStreamConstants.END_ELEMENT: xmlWriter.writeEndElement(); break; case XMLStreamConstants.END_DOCUMENT: xmlWriter.writeEndDocument(); break; case XMLStreamConstants.SPACE: break; case XMLStreamConstants.COMMENT: xmlWriter.writeComment(reader.getText()); break; case XMLStreamConstants.DTD: xmlWriter.writeDTD(reader.getText()); break; case XMLStreamConstants.PROCESSING_INSTRUCTION: xmlWriter.writeProcessingInstruction(reader.getPITarget(), reader.getPIData()); break; case XMLStreamConstants.ENTITY_REFERENCE: xmlWriter.writeEntityRef(reader.getLocalName()); break; default: throw new OMException(); } } xmlWriter.writeEndDocument(); xmlWriter.flush(); xmlWriter.close(); } public XMLStreamReader getReader() throws XMLStreamException { try { inputStream.reset(); } catch (IOException e) { logger.error("#getReader. Could not reuse JSON stream from JSON Data Source. Error>> " + e.getLocalizedMessage()); throw new XMLStreamException("Could not reuse JSON stream from JSON Data Source.", e); } return JsonUtil.getReader(inputStream, false); // Do not add PIs to the XML output of this reader } }