Updated WCPS source code to match spec WCPS 1.0.0

1 files changed, 323 insertions, 0 deletions

diff --git a/src/wcps/server/servlet/WCPSServlet.java b/src/wcps/server/servlet/WCPSServlet.java
new file mode 100644
index 0000000..e072614
--- /dev/null
+++ b/src/wcps/server/servlet/WCPSServlet.java
@@ -0,0 +1,323 @@
+/*

+ * This file is part of PetaScope.

+ *

+ * PetaScope 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 3 of

+ * the License, or (at your option) any later version.

+ *

+ * PetaScope 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 PetaScope. If not, see <http://www.gnu.org/licenses/>.

+ *

+ * For more information please see <http://www.PetaScope.org>

+ * or contact Peter Baumann via <baumann@rasdaman.com>.

+ *

+ * Copyright 2009 Jacobs University Bremen, Peter Baumann.

+ */

+

+

+package wcps.server.servlet;

+

+import org.apache.commons.fileupload.FileItem;

+import org.apache.commons.fileupload.disk.DiskFileItemFactory;

+import org.apache.commons.fileupload.servlet.ServletFileUpload;

+

+import org.xml.sax.InputSource;

+

+//This is the servlet interface of WCPS. It mostly consists of sanity checks and initialization,

+//the meat is onyl a few lines. The WCPS class does the actual work.

+

+import wcps.server.core.CachedMetadataSource;

+import wcps.server.core.DbMetadataSource;

+import wcps.server.core.ProcessCoveragesRequest;

+import wcps.server.core.WCPS;

+

+import java.io.File;

+import java.io.FileInputStream;

+import java.io.IOException;

+import java.io.OutputStream;

+import java.io.PrintWriter;

+

+//import syntaxParser.SyntaxErrorException;

+import java.io.StringBufferInputStream;

+

+import java.util.Iterator;

+import java.util.List;

+import java.util.Properties;

+

+import javax.servlet.ServletException;

+import javax.servlet.http.HttpServlet;

+import javax.servlet.http.HttpServletRequest;

+import javax.servlet.http.HttpServletResponse;

+

+//Note an important limitation: this will only return the first result if several are available. 

+//The reason is that WCPS currently has no standardized way to return multiple byte streams to

+//the user.

+public class WCPSServlet extends HttpServlet

+{

+	private static final long serialVersionUID = 84786549L;

+	private Properties dbParams;

+	private DbMetadataSource metadataSource;

+	private String rasdamanDatabase;

+	private String rasdamanUrl;

+	private WCPS wcps;

+

+	public void init() throws ServletException

+	{

+		try

+		{

+			dbParams = new Properties();

+			System.out.println("WCPS: loading database properties");

+			dbParams.load(

+			    new FileInputStream(

+				getServletContext().getRealPath("/dbparams.properties")));

+			rasdamanUrl      = dbParams.getProperty("rasdaman_url");

+			rasdamanDatabase = dbParams.getProperty("rasdaman_database");

+

+			System.out.println("WCPS: initializing metadata database");

+			metadataSource =

+				new DbMetadataSource(dbParams.getProperty("metadata_driver"),

+						     dbParams.getProperty("metadata_url"),

+						     dbParams.getProperty("metadata_user"),

+						     dbParams.getProperty("metadata_pass"), false);

+

+			System.out.println("WCPS: initializing WCPS core");

+			wcps = new WCPS(

+                        new File(getServletContext().getRealPath("/xml/wcps/wcpsProcessCoverages.xsd")),

+                        new CachedMetadataSource(metadataSource));

+

+			System.out.println("WCPS: initialization complete");

+		}

+		catch (Exception e)

+		{

+    			System.out.println("WCPS: initialization error");

+			System.out.println("WCPS: closing metadata database");

+

+			if (metadataSource != null)

+			{

+				metadataSource.close();

+			}

+

+			System.out.println("WCPS: done with init error");

+			throw new ServletException("WCPS initialization error", e);

+		}

+

+	}

+

+	public void doGet(HttpServletRequest request, HttpServletResponse response)

+	    throws ServletException, IOException

+	{

+		System.out.println("WCPS: invoked with GET");

+		printUsage(response);

+

+	}

+

+	public void doPost(HttpServletRequest request, HttpServletResponse response)

+	    throws ServletException, IOException

+	{

+		System.out.println("WCPS: invoked with POST");

+		OutputStream webOut = null;

+

+		try

+		{

+			String xmlRequest = null;

+

+			if (ServletFileUpload.isMultipartContent(request))

+			{

+				@SuppressWarnings(

+					"unchecked") Iterator<FileItem> fileItems =

+						(Iterator<FileItem>) (new ServletFileUpload(

+						    new DiskFileItemFactory())).parseRequest(

+							request).iterator();

+

+				if (!fileItems.hasNext())

+				{

+					throw new IOException(

+					    "Multipart POST request contains no parts");

+				}

+

+				FileItem fileItem = fileItems.next();

+

+				if (fileItems.hasNext())

+				{

+					throw new IOException(

+					    "Multipart POST request contains too many parts");

+				}

+

+				if (!fileItem.isFormField()

+				    && fileItem.getContentType().equals("text/xml"))

+				{

+					xmlRequest = fileItem.getString();

+				}

+

+				if (xmlRequest == null)

+				{

+					System.out.println(

+					    "WCPS: no XML file was uploaded within multipart POST request");

+					printUsage(response);

+					return;

+				}

+

+				System.out.println(

+				    "WCPS: received XML via a multipart POST request");

+			}

+			else

+			{

+				String xml   = request.getParameter("xml");

+				String query = request.getParameter("query");

+

+				if (xml != null)

+				{

+					System.out.println("WCPS: received XML via a 'xml' parameter in a POST request");

+					xmlRequest = xml;

+				}

+				else if (query != null)

+				{

+					System.out.println("WCPS: received the following  query via a 'query' " +

+                            "parameter in a POST request:");

+					System.out.println(query);

+

+                    xmlRequest = ProcessCoveragesRequest.abstractQueryToXmlQuery(query);

+                    System.out.println("WCPS: transformed the abstract syntax query into an XML query!");

+				}

+				else

+				{

+					System.out.println("WCPS: no request was received");

+					printUsage(response);

+					return;

+				}

+			}

+

+			System.out.println("WCPS: received the following request:");

+			System.out.println(xmlRequest);

+

+			System.out.println("WCPS: preparing request");

+			ProcessCoveragesRequest processCoverageRequest =

+				wcps.pcPrepare(

+				    rasdamanUrl, rasdamanDatabase,

+				    new InputSource(new StringBufferInputStream(xmlRequest)));

+

+			System.out.println("[" + processCoverageRequest.getMime() + "] "

+					   + processCoverageRequest.getRasqlQuery());

+

+			String query = processCoverageRequest.getRasqlQuery();

+

+			System.out.println("Resulting RasQL query: " + query);

+			String mimetype = processCoverageRequest.getMime();

+

+			System.out.println("WCPS: executing request");

+

+			List<byte[]> results = processCoverageRequest.execute();

+

+			System.out.println("WCPS: setting response mimetype to " + mimetype);

+			response.setContentType(mimetype);

+			System.out.println("WCPS: returning response");

+			webOut = response.getOutputStream();

+			webOut.write(results.get(0));

+			System.out.println("WCPS: done");

+		}

+		catch (Exception e)

+		{

+			printError(response, "Error: " + e.getMessage(), e);

+		}

+		finally

+		{

+			if (webOut != null)

+			{

+				try

+				{

+					webOut.close();

+				}

+				catch (IOException e) {}

+			}

+		}

+	}

+

+	public void destroy()

+	{

+		super.destroy();

+

+	}

+

+	public String getServletInfo()

+	{

+		return "Web Coverage Processing Service";

+

+	}

+

+	private void printError(HttpServletResponse response, String message, Exception e)

+	    throws IOException

+	{

+		System.out.println("WCPS: error");

+		System.out.println("WCPS: setting response mimetype to text/html; charset=utf-8");

+		response.setContentType("text/html; charset=utf-8");

+		System.out.println("WCPS: returning the following error message");

+		e.printStackTrace(System.out);

+		System.out.println("WCPS: end of error message");

+		PrintWriter out = new PrintWriter(response.getOutputStream());

+

+		out.println(

+		    "<html><head><title>Web Coverage Processing Service</title></head><body>");

+		out.println("<h1>An error has occured</h1>");

+		out.println("<p>" + message + "</p>");

+		out.println("<p>Stack trace:<br/><small>");

+		e.printStackTrace(out);

+		out.println("</small></p></body></html>");

+		out.close();

+		System.out.println("WCPS: done with error");

+

+	}

+

+	private void printUsage(HttpServletResponse response) throws IOException

+	{

+		System.out.println("WCPS: setting response mimetype to text/html; charset=utf-8");

+		System.out.println("WCPS: returning usage message");

+		response.setContentType("text/html; charset=utf-8");

+		PrintWriter out = new PrintWriter(response.getOutputStream());

+

+		out.println(

+		    "<html><head><title>Web Coverage Processing Service</title></head><body>");

+		out.println("<h1>Hello</h1>");

+		out.println("<p>There are 3 ways to invoke this service:</p>");

+		out.println(

+		    "<p>1. Upload a ProcessCoverage XML request as a multupart/form-data POST request containing a file. You can use the form below.</p>");

+		out.println(

+		    "<form action=\"\" method=\"post\" enctype=\"multipart/form-data\"><input type=\"file\" accept=\"text/xml\" size=\"64\" name=\"xmlfile\"/> <input type=\"submit\" value=\"Send\"/></form>");

+		out.println(

+		    "<p>2. Enter a ProcessCoverage XML request and submit it as a POST request with a parameter named <b>xml</b>. You can use the form below.</p>");

+		out.println(

+		    "<form action=\"\" method=\"post\"><textarea cols=\"64\" rows=\"16\" name=\"xml\"></textarea><input type=\"submit\" value=\"Send\"/></form>");

+		out.println(

+		    "<p>3. Enter a ProcessCoverage request in WCPS abstract syntax and submit it as a POST request with a parameter named <b>query</b>. You can use the form below.</p>");

+		out.println(

+		    "<form action=\"\" method=\"post\"><textarea cols=\"64\" rows=\"4\" name=\"query\"></textarea><input type=\"submit\" value=\"Send\"/></form>");

+		out.println("</body></html>");

+		out.close();

+		System.out.println("WCPS: done nothing");

+

+	}

+

+	void FormatSyntaxException(Exception e, HttpServletResponse response, String query)

+	    throws IOException

+	{

+		int column = 1;

+

+		response.setContentType("text/html; charset=utf-8");

+		PrintWriter o = new PrintWriter(response.getOutputStream());

+

+		o.println(

+		    "<html><head><title>Web Coverage Processing Service</title></head><body>");

+		o.println("<p>There seems to be a syntax problem with your query:</p>");

+		o.println("<p><font color='00FF00'>" + query.substring(0, column)

+			  + "</font><font color='FF0000'>" + query.substring(column)

+			  + "</font></p>");

+		o.println("<p>Please correct it and try again.</p></body></html>");

+		o.close();

+		System.out.println("WCPS: Syntax Error reported");

+	}

+}