diff options
Diffstat (limited to 'petascope/src/petascope/wcps/server/servlet/WCPSServlet.java')
| -rw-r--r-- | petascope/src/petascope/wcps/server/servlet/WCPSServlet.java | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/petascope/src/petascope/wcps/server/servlet/WCPSServlet.java b/petascope/src/petascope/wcps/server/servlet/WCPSServlet.java new file mode 100644 index 0000000..4a00969 --- /dev/null +++ b/petascope/src/petascope/wcps/server/servlet/WCPSServlet.java @@ -0,0 +1,257 @@ +/*
+ * 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 petascope.wcps.server.servlet;
+
+import org.apache.commons.fileupload.FileItem;
+import org.apache.commons.fileupload.disk.DiskFileItemFactory;
+import org.apache.commons.fileupload.servlet.ServletFileUpload;
+
+
+//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 petascope.wcps.server.core.DbMetadataSource;
+import petascope.wcps.server.core.ProcessCoveragesRequest;
+import petascope.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 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;
+import org.apache.commons.io.FileUtils;
+import org.apache.commons.io.IOUtils;
+
+//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 Properties dbParams;
+ private DbMetadataSource metadataSource;
+ private String rasdamanDatabase;
+ private String rasdamanUrl;
+ private WCPS wcps;
+ // path to the default HTML response of the servlet
+ private String servletHtmlPath = "/templates/wcps-servlet.html";
+ // String containing the HTML code for the default response
+ private String defaultHtmlResponse;
+
+ public void init() throws ServletException {
+ try {
+ dbParams = new Properties();
+ System.out.println("WCPS: loading database properties");
+ dbParams.load(
+ new FileInputStream(
+ getServletContext().getRealPath("/settings.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/ogc/wcps/1.0.0/wcpsProcessCoverages.xsd")),
+ // new CachedMetadataSource(metadataSource)); // removed metadata caching (andrei)
+ metadataSource);
+
+ servletHtmlPath = getServletContext().getRealPath(servletHtmlPath);
+ defaultHtmlResponse = FileUtils.readFileToString(new File(servletHtmlPath));
+
+ 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, IOUtils.toInputStream(xmlRequest));
+
+ String query = processCoverageRequest.getRasqlQuery();
+ String mime = processCoverageRequest.getMime();
+
+ System.out.println("[" + mime + "] " + query);
+
+ System.out.println("Resulting RasQL query: " + query);
+
+ System.out.println("WCPS: executing request");
+
+ List<byte[]> results = processCoverageRequest.execute();
+
+ System.out.println("WCPS: setting response mimetype to " + mime);
+ response.setContentType(mime);
+ 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 (Project PetaScope)";
+
+ }
+
+ 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(defaultHtmlResponse);
+
+ out.close();
+ System.out.println("WCPS: done nothing");
+
+ }
+}
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