Java tutorial
/* * 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 edu.ucsd.xmlrpc.xmlrpc.server; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.util.List; import java.util.zip.GZIPInputStream; import java.util.zip.GZIPOutputStream; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.xml.sax.ContentHandler; import org.xml.sax.InputSource; import org.xml.sax.SAXException; import org.xml.sax.XMLReader; import edu.ucsd.xmlrpc.xmlrpc.XmlRpcException; import edu.ucsd.xmlrpc.xmlrpc.XmlRpcRequest; import edu.ucsd.xmlrpc.xmlrpc.XmlRpcRequestConfig; import edu.ucsd.xmlrpc.xmlrpc.client.XmlRpcClientRequestImpl; import edu.ucsd.xmlrpc.xmlrpc.common.ServerStreamConnection; import edu.ucsd.xmlrpc.xmlrpc.common.XmlRpcStreamRequestConfig; import edu.ucsd.xmlrpc.xmlrpc.common.XmlRpcStreamRequestProcessor; import edu.ucsd.xmlrpc.xmlrpc.parser.XmlRpcRequestParser; import edu.ucsd.xmlrpc.xmlrpc.serializer.DefaultXMLWriterFactory; import edu.ucsd.xmlrpc.xmlrpc.serializer.XmlRpcWriter; import edu.ucsd.xmlrpc.xmlrpc.serializer.XmlWriterFactory; import edu.ucsd.xmlrpc.xmlrpc.util.SAXParsers; import edu.ucsd.xmlrpc.xmlrpc.webserver.StoredRequest; import edu.ucsd.xmlrpc.xmlrpc.webserver.WebServer; /** Extension of {@link XmlRpcServer} with support for reading * requests from a stream and writing the response to another * stream. */ public abstract class XmlRpcStreamServer extends XmlRpcServer implements XmlRpcStreamRequestProcessor { private static final Log log = LogFactory.getLog(XmlRpcStreamServer.class); private XmlWriterFactory writerFactory = new DefaultXMLWriterFactory(); private static final XmlRpcErrorLogger theErrorLogger = new XmlRpcErrorLogger(); private XmlRpcErrorLogger errorLogger = theErrorLogger; protected XmlRpcRequest getRequest(final XmlRpcStreamRequestConfig pConfig, InputStream pStream) throws XmlRpcException { final XmlRpcRequestParser parser = new XmlRpcRequestParser(pConfig, getTypeFactory()); final XMLReader xr = SAXParsers.newXMLReader(); xr.setContentHandler(parser); try { xr.parse(new InputSource(pStream)); } catch (SAXException e) { Exception ex = e.getException(); if (ex != null && ex instanceof XmlRpcException) { throw (XmlRpcException) ex; } throw new XmlRpcException("Failed to parse XML-RPC request: " + e.getMessage(), e); } catch (IOException e) { throw new XmlRpcException("Failed to read XML-RPC request: " + e.getMessage(), e); } final List params = parser.getParams(); // Ucsd modified code return new XmlRpcClientRequestImpl(pConfig, parser.getMethodName(), parser.getParams(), parser.getJobID()); // end } protected XmlRpcWriter getXmlRpcWriter(XmlRpcStreamRequestConfig pConfig, OutputStream pStream) throws XmlRpcException { ContentHandler w = getXMLWriterFactory().getXmlWriter(pConfig, pStream); return new XmlRpcWriter(pConfig, w, getTypeFactory()); } protected void writeResponse(XmlRpcStreamRequestConfig pConfig, OutputStream pStream, Object pResult) throws XmlRpcException { try { getXmlRpcWriter(pConfig, pStream).write(pConfig, pResult); } catch (SAXException e) { throw new XmlRpcException("Failed to write XML-RPC response: " + e.getMessage(), e); } } /** * This method allows to convert the error into another error. For example, this * may be an error, which could be deserialized by the client. */ protected Throwable convertThrowable(Throwable pError) { return pError; } protected void writeError(XmlRpcStreamRequestConfig pConfig, OutputStream pStream, Throwable pError) throws XmlRpcException { final Throwable error = convertThrowable(pError); final int code; final String message; if (error instanceof XmlRpcException) { XmlRpcException ex = (XmlRpcException) error; code = ex.code; } else { code = 0; } message = error.getMessage(); try { getXmlRpcWriter(pConfig, pStream).write(pConfig, code, message, error); } catch (SAXException e) { throw new XmlRpcException("Failed to write XML-RPC response: " + e.getMessage(), e); } } /** Sets the XML Writer factory. * @param pFactory The XML Writer factory. */ public void setXMLWriterFactory(XmlWriterFactory pFactory) { writerFactory = pFactory; } /** Returns the XML Writer factory. * @return The XML Writer factory. */ public XmlWriterFactory getXMLWriterFactory() { return writerFactory; } protected InputStream getInputStream(XmlRpcStreamRequestConfig pConfig, ServerStreamConnection pConnection) throws IOException { InputStream istream = pConnection.newInputStream(); if (pConfig.isEnabledForExtensions() && pConfig.isGzipCompressing()) { istream = new GZIPInputStream(istream); } return istream; } /** Called to prepare the output stream. Typically used for enabling * compression, or similar filters. * @param pConnection The connection object. */ protected OutputStream getOutputStream(ServerStreamConnection pConnection, XmlRpcStreamRequestConfig pConfig, OutputStream pStream) throws IOException { if (pConfig.isEnabledForExtensions() && pConfig.isGzipRequesting()) { return new GZIPOutputStream(pStream); } else { return pStream; } } /** Called to prepare the output stream, if content length is * required. * @param pConfig The configuration object. * @param pSize The requests size. */ protected OutputStream getOutputStream(XmlRpcStreamRequestConfig pConfig, ServerStreamConnection pConnection, int pSize) throws IOException { return pConnection.newOutputStream(); } /** Returns, whether the requests content length is required. * @param pConfig The configuration object. */ protected boolean isContentLengthRequired(XmlRpcStreamRequestConfig pConfig) { return false; } /** Returns, whether the /** Processes a "connection". The "connection" is an opaque object, which is * being handled by the subclasses. * @param pConfig The request configuration. * @param pConnection The "connection" being processed. * @throws XmlRpcException Processing the request failed. */ public void execute(XmlRpcStreamRequestConfig pConfig, ServerStreamConnection pConnection, WebServer wServer) throws XmlRpcException { log.debug("execute: ->"); Object result; Throwable error; try { InputStream istream = null; try { istream = getInputStream(pConfig, pConnection); XmlRpcRequest request = getRequest(pConfig, istream); // Ucsd modified code StoredRequest storedRequest = new StoredRequest((XmlRpcClientRequestImpl) request); if (wServer != null) { wServer.addRequest(storedRequest.getRequest().getJobID(), storedRequest); } result = execute(request); storedRequest.setValid(true); ; storedRequest.setResult(result); //TODO DEMO remove if (result.equals(-9)) { throw new Throwable("Server Disconnected"); } // end istream.close(); istream = null; error = null; log.debug("execute: Request performed successfully"); } catch (Throwable t) { logError(t); result = null; error = t; } finally { if (istream != null) { try { istream.close(); } catch (Throwable ignore) { } } } boolean contentLengthRequired = isContentLengthRequired(pConfig); ByteArrayOutputStream baos; OutputStream ostream; if (contentLengthRequired) { baos = new ByteArrayOutputStream(); ostream = baos; } else { baos = null; ostream = pConnection.newOutputStream(); } ostream = getOutputStream(pConnection, pConfig, ostream); try { if (error == null) { writeResponse(pConfig, ostream, result); } else { writeError(pConfig, ostream, error); } ostream.close(); ostream = null; } finally { if (ostream != null) { try { ostream.close(); } catch (Throwable ignore) { } } } if (baos != null) { OutputStream dest = getOutputStream(pConfig, pConnection, baos.size()); try { baos.writeTo(dest); dest.close(); dest = null; } finally { if (dest != null) { try { dest.close(); } catch (Throwable ignore) { } } } } pConnection.close(); pConnection = null; } catch (IOException e) { throw new XmlRpcException("I/O error while processing request: " + e.getMessage(), e); } finally { if (pConnection != null) { try { pConnection.close(); } catch (Throwable ignore) { } } } log.debug("execute: <-"); } protected void logError(Throwable t) { final String msg = t.getMessage() == null ? t.getClass().getName() : t.getMessage(); errorLogger.log(msg, t); } /** * Returns the error logger. */ public XmlRpcErrorLogger getErrorLogger() { return errorLogger; } /** * Sets the error logger. */ public void setErrorLogger(XmlRpcErrorLogger pErrorLogger) { errorLogger = pErrorLogger; } }