Annotation of java/classes/org/w3c/rdf/examples/SiRPACServlet.java, revision 1.17
1.1 barstow 1: /**
2: * SiRPACServlet - Simple RDF Parser & Compiler Servlet wrapper
3: *
4: * Copyright © World Wide Web Consortium, (Massachusetts Institute of
5: * Technology, Institut National de Recherche en Informatique et en
6: * Automatique, Keio University).
7: *
8: * All Rights Reserved.
9: *
10: * Please see the full Copyright clause at
11: * <http://www.w3.org/Consortium/Legal/copyright-software.html>
12: *
1.3 barstow 13: * This servlet is a wrapper for the SiRPAC RDF parser. The servlet
1.7 barstow 14: * expects the following variables through the POST method:
1.3 barstow 15: *
1.16 barstow 16: * 1. RDF - the RDF/XML document
17: * 2. BAGS - if "on", each Description should have its own Bag;
18: * the default is not to do this.
19: * 3. STREAM if "on", the stream mode is turned off so that aboutEach
20: * and aboutEachPrefix are supported.
21: * 4. SAVE_RDF if "on", the RDF will be copied to a file.
22: * 5. URI - the URI to parse [instead of the RDF]; may not be specified
1.1 barstow 23: *
1.7 barstow 24: * @author Art Barstow <barstow@w3.org>
1.1 barstow 25: *
1.7 barstow 26: * The graphics package is AT&T's GraphVis tool.
1.1 barstow 27: */
28:
29: package org.w3c.rdf.examples;
30:
31: import java.io.*;
1.16 barstow 32: import java.net.MalformedURLException;
33: import java.net.URL;
1.1 barstow 34: import java.util.StringTokenizer;
35: import java.util.Enumeration;
36: import javax.servlet.*;
37: import javax.servlet.http.*;
38:
39: import org.xml.sax.InputSource;
40: import org.xml.sax.Parser;
41: import org.xml.sax.SAXException;
42: import org.xml.sax.helpers.*;
43:
44: import org.w3c.rdf.model.*;
45: import org.w3c.rdf.syntax.*;
46: import org.w3c.rdf.syntax.RDFConsumer;
47: import org.w3c.rdf.util.xml.DumpConsumer;
48: import org.w3c.rdf.util.xml.ErrorStore;
1.16 barstow 49: import org.w3c.rdf.util.xml.GenericParser;
1.1 barstow 50: import org.w3c.rdf.implementation.model.StatementImpl;
51: import org.w3c.rdf.implementation.model.NodeFactoryImpl;
52: import org.w3c.rdf.implementation.syntax.sirpac.*;
53:
54: public class SiRPACServlet extends HttpServlet
55: {
1.17 ! barstow 56: final static public String REVISION = "$Id: SiRPACServlet.java,v 1.16 2000/12/18 20:07:31 barstow Exp $";
1.1 barstow 57:
1.7 barstow 58: // The email address for bug reports
1.4 barstow 59: private static final String MAIL_TO = "barstow@w3.org";
1.10 barstow 60:
61: // Names of the POST parameters
62: // The XML'ized RDF
63: private static final String POST_TEXT = "RDF";
64: // Flag for turning on treating each Description as a bag
65: private static final String POST_BAG = "BAGS";
66: // Flag for turning off SiRPAC's stream parsing mode
67: private static final String POST_STREAM_MODE = "STREAM";
1.14 barstow 68: // Flag to indicate that the RDF should be copied to a file
69: private static final String POST_SAVE_RDF = "SAVE_RDF";
1.16 barstow 70: // The URI of the RDF to parse
71: private static final String POST_URI = "URI";
1.3 barstow 72:
73: // Names of the servlet's parameters
1.5 barstow 74: private static final String SIRPAC_TMP_DIR = "SIRPAC_TMP_DIR";
75: private static final String GRAPH_VIZ_ROOT = "GRAPH_VIZ_ROOT";
76: private static final String GRAPH_VIZ_PATH = "GRAPH_VIZ_PATH";
77: private static final String GRAPH_VIZ_LIB_DIR = "GRAPH_VIZ_LIB_DIR";
78: private static final String GRAPH_VIZ_FONT_DIR = "GRAPH_VIZ_FONT_DIR";
1.3 barstow 79:
80: // Variables for the servlet's parameters
1.5 barstow 81: private static String m_SiRPACTmpDir = null;
82: private static String m_GraphVizPath = null;
83: private static String m_GraphVizFontDir = null;
84: private static String m_GraphVizLibDir = null;
1.4 barstow 85:
86: // Names of environment variable need by GraphVis
87: private static String DOTFONTPATH = "DOTFONTPATH";
88: private static String LD_LIBRARY_PATH = "LD_LIBRARY_PATH";
89:
90: // Names used for temporary files
91: private static final String TMP_FILE_PREFIX = "sirpac_";
92: private static final String TMP_DIR_SUFFIX = ".tmp";
93: private static final String DOT_SUFFIX = ".dot";
94: private static final String GIF_SUFFIX = ".gif";
1.14 barstow 95: private static final String RDF_SUFFIX = ".rdf";
1.3 barstow 96:
1.6 barstow 97: // Default GraphViz parameter names and their default values
98: private static final String NODE_COLOR = "NODE_COLOR";
99: private static final String DEFAULT_NODE_COLOR = "black";
100:
101: private static final String NODE_TEXT_COLOR = "NODE_TEXT_COLOR";
102: private static final String DEFAULT_NODE_TEXT_COLOR = "black";
103:
104: private static final String EDGE_COLOR = "EDGE_COLOR";
105: private static final String DEFAULT_EDGE_COLOR = "black";
106:
107: private static final String EDGE_TEXT_COLOR = "EDGE_TEXT_COLOR";
108: private static final String DEFAULT_EDGE_TEXT_COLOR = "black";
109:
110: private static final String ORIENTATION = "ORIENTATION";
111: private static final String DEFAULT_ORIENTATION = "TB"; // Top to Bottom
112:
113: private static final String FONT_SIZE = "FONT_SIZE";
114: private static final String DEFAULT_FONT_SIZE = "10";
115:
116: // Fonts are not currently configurable
117: private static final String DEFAULT_FONT = "arial";
118:
1.8 barstow 119: // Servlet name
120: private static final String SERVLET_NAME = "SiRPACServlet";
121:
1.3 barstow 122: // The parser
123: private SiRPAC m_sirpac = null;
124: // The error handler
125: private ErrorStore m_errorHandler;
1.1 barstow 126:
1.3 barstow 127: /*
1.4 barstow 128: * Create a File object in the m_SiRPACTmpDir directory
1.3 barstow 129: *
1.4 barstow 130: *@param directory the file's directory
131: *@param prefix the file's prefix name (not its directory)
132: *@param suffix the file's suffix or extension name
133: *@return a File object if a temporary file is created; null otherwise
1.3 barstow 134: */
1.4 barstow 135: private File createTempFile (String directory, String prefix, String suffix) {
136: File f;
137: try {
138: File d = new File(directory);
139: f = File.createTempFile(prefix, suffix, d);
140: } catch (Exception e) {
141: return null;
142: }
143: return f;
144: }
145:
1.14 barstow 146:
147: /*
148: * Copy the given string of RDF to a file in the given directory
149: *
150: *@param dir the file's directory
151: *@param rdf the string of RDF
152: *@return void
153: */
154:
155: private void copyRDFStringToFile(String tmpDir, String rdf)
156: {
157: try {
158: // Generate a unique file name
159: File tmpFile = createTempFile(tmpDir, TMP_FILE_PREFIX, RDF_SUFFIX);
160: if (tmpFile == null) {
161: // Not really a critical error, just return
162: return;
163: }
164:
165: // Create a PrintWriter for the GraphViz consumer
166: FileWriter fw = new FileWriter(tmpFile);
167: PrintWriter pw = new PrintWriter(fw);
168:
169: pw.println(rdf);
170: pw.close();
171: } catch (Exception e) {
172: // Just return - not critical
173: return;
174: }
175: }
176:
1.4 barstow 177: /*
178: * Invokes the GraphVis program to create a GIF image from the
179: * the given DOT data file
180: *
181: *@param dotFileName the name of the DOT data file
182: *@param gifFileName the name of the GIF data file
183: *@return true if success; false if any failure occurs
184: */
185: private boolean generateGifFile(String dotFileName, String gifFileName) {
1.5 barstow 186: String environment[] = {DOTFONTPATH + "=" + m_GraphVizFontDir,
187: LD_LIBRARY_PATH + "=" + m_GraphVizLibDir};
1.4 barstow 188:
1.5 barstow 189: String cmdArray[] = {m_GraphVizPath, "-Tgif", "-o", gifFileName, dotFileName};
1.4 barstow 190:
191: Runtime rt = Runtime.getRuntime();
192: try {
193: Process p = rt.exec(cmdArray, environment);
194: p.waitFor();
195: } catch (Exception e) {
196: return false;
197: }
198:
199: return true;
1.3 barstow 200: }
1.1 barstow 201:
1.3 barstow 202: /*
1.6 barstow 203: * Returns a parameter from a request or the parameter's default
204: * value.
205: *
206: *@param req a Servlet request
207: *@return if the request contains the specfied parameter its value
208: * in the request is returned; otherwise its default value is
209: * returned
210: */
211: private String getParameter(HttpServletRequest req, String param, String defString) {
212: String s = req.getParameter(param);
213: return (s == null) ? defString : s;
214: }
215:
216: /*
217: * If the request contains any graph-related parameters, pass them
218: * to the graph consumer for handling
219: *
220: *@param req the response
221: *@param consumer the GraphViz consumer
222: */
223: private void processGraphParameters (HttpServletRequest req, GraphVizDumpConsumer consumer) {
224: // Look for colors
225:
226: String s;
227:
228: String nodeColor = getParameter (req, NODE_COLOR, DEFAULT_NODE_COLOR);
229: String nodeTextColor = getParameter (req, NODE_TEXT_COLOR, DEFAULT_NODE_TEXT_COLOR);
230: String edgeColor = getParameter (req, EDGE_COLOR, DEFAULT_EDGE_COLOR);
231: String edgeTextColor = getParameter (req, EDGE_TEXT_COLOR, DEFAULT_EDGE_TEXT_COLOR);
232: String fontSize = getParameter (req, FONT_SIZE, DEFAULT_FONT_SIZE);
233:
234: // Orientation must be either
235: String orientation = req.getParameter (ORIENTATION);
236: if (orientation.equals("Left to Right"))
237: orientation = "LR";
238: else
239: orientation = DEFAULT_ORIENTATION;
240:
241: // Add an attribute for all of the graph's nodes
242: consumer.addGraphAttribute("node [fontname=" + DEFAULT_FONT +
243: ",fontsize=" + fontSize +
244: ",color=" + nodeColor +
245: ",fontcolor=" + nodeTextColor + "]");
246:
247: // Add an attribute for all of the graph's edges
248: consumer.addGraphAttribute("edge [fontname=" + DEFAULT_FONT +
249: ",fontsize=" + fontSize +
250: ",color=" + edgeColor +
251: ",fontcolor=" + edgeTextColor + "]");
252:
253: // Add an attribute for the orientation
254: consumer.addGraphAttribute("rankdir=" + orientation + ";");
255: }
256:
257: /*
1.3 barstow 258: * Generate a graph of the RDF data model
259: *
1.4 barstow 260: *@param out the servlet's output stream
1.6 barstow 261: *@param rdf the RDF text
262: *@param req a Servlet request
1.3 barstow 263: */
1.14 barstow 264: private void generateGraph (ServletOutputStream out, String rdf, HttpServletRequest req, boolean saveRDF) {
1.2 barstow 265: try {
266: out.println("<hr title=\"visualisation\">");
1.3 barstow 267: out.println("<h3>Graph of the data model</h3>");
268:
1.4 barstow 269: // Stop if any of the parameters are missing
1.5 barstow 270: if (m_SiRPACTmpDir == null || m_GraphVizPath == null ||
271: m_GraphVizFontDir == null || m_GraphVizLibDir == null) {
1.8 barstow 272:
273: // Put the paths in a comment in the returned content
274: out.println("<!-- SIRPAC TMP = " + m_SiRPACTmpDir);
275: out.println("GRAPH VIZ = " + m_GraphVizPath);
276: out.println("GRAPH LIB = " + m_GraphVizLibDir);
277: out.println("GRAPH FON = " + m_GraphVizFontDir + " -->");
278:
1.3 barstow 279: out.println("Servlet initialization failed. A graph cannot be generated.");
280: return;
281: }
282:
1.4 barstow 283: // The temporary directory
284: String tmpDir = m_SiRPACTmpDir;
1.3 barstow 285:
1.4 barstow 286: // Must generate a unique file name that the DOT consumer
287: // will use
288: File dotFile = createTempFile(tmpDir, TMP_FILE_PREFIX, DOT_SUFFIX);
289: if (dotFile == null) {
290: out.println("Failed to create a temporary DOT file. A graph cannot be generated.");
1.3 barstow 291: return;
292: }
293:
294: // Create a PrintWriter for the GraphViz consumer
1.4 barstow 295: FileWriter fw = new FileWriter(dotFile);
1.3 barstow 296: PrintWriter pw = new PrintWriter(fw);
297:
298: // Run the parser using the DOT consumer to capture
299: // the output in a file
300: StringReader sr = new StringReader (rdf);
301: InputSource is = new InputSource (sr);
302: GraphVizDumpConsumer consumer = new GraphVizDumpConsumer(pw);
303:
1.6 barstow 304: // Process any graph-related parameters in the request
305: processGraphParameters(req, consumer);
1.15 barstow 306:
307: // Reinitialize the parser's genid counter so the genids
308: // of the triple will match the genids of the graph
309: m_sirpac.setGenidNumber(0);
1.6 barstow 310:
1.3 barstow 311: try {
312: m_sirpac.parse(is, consumer);
313: } catch (Exception e) {
314: out.println("An attempt to generate the graph data failed ("
315: + e.getMessage() + ").");
1.4 barstow 316: pw.close();
317: dotFile.delete();
1.3 barstow 318: return;
319: }
320:
1.4 barstow 321: // Must close the DOT input file so the GraphViz can
322: // open and read it
323: pw.close();
324:
325: // Must generate a unique file name for the GIF file
326: // that will be created
327: File gifFile = createTempFile(tmpDir, TMP_FILE_PREFIX, GIF_SUFFIX);
328: if (gifFile == null) {
329: out.println("Failed to create a temporary GIF file. A graph cannot be generated.");
330: dotFile.delete();
331: return;
332: }
333:
1.3 barstow 334: // Pass the DOT data file to the GraphViz dot program
1.4 barstow 335: // so it can create a GIF image of the data model
336: String dotFileName = dotFile.getAbsolutePath();
337: String gifFileName = gifFile.getAbsolutePath();
338:
339: if (!generateGifFile(dotFileName, gifFileName)) {
340: out.println("An attempt to create a graph failed.");
341: dotFile.delete();
342: gifFile.delete();
343: return;
344: }
1.3 barstow 345:
1.7 barstow 346: // Cleanup
347: dotFile.delete();
1.3 barstow 348:
1.9 barstow 349: // NOTE: Cannot delete the GIF file here because its
350: // pathname is returned to the client
1.8 barstow 351: String imagePath = SERVLET_NAME +
1.7 barstow 352: TMP_DIR_SUFFIX + File.separator +
353: gifFile.getName();
1.2 barstow 354:
1.4 barstow 355: if (gifFile.length() > 0)
356: out.println("<img src=\"" + imagePath + "\"/>");
357: else
358: out.println("The graph image file is empty.");
1.2 barstow 359:
1.14 barstow 360: // One last thing to do before exiting - copy the RDF to a file
361: if (saveRDF)
362: copyRDFStringToFile(tmpDir, rdf);
363:
1.2 barstow 364: } catch (Exception e) {
365: System.err.println("Exception: " + e.getMessage());
366: }
367: }
368:
369: /*
1.3 barstow 370: * Search the given string for substring "key"
1.2 barstow 371: * and if it is found, replace it with string "replacement"
372: *
1.4 barstow 373: *@param input the input string
374: *@param key the string to search for
375: *@param replacement the string to replace all occurences of "key"
1.2 barstow 376: *@return if no substitutions are done, input is returned; otherwise
377: * a new string is returned.
378: */
1.12 barstow 379: public static String replaceString(String input, String key, String replacement) {
1.2 barstow 380: StringBuffer sb = new StringBuffer("");
381: StringTokenizer st = new StringTokenizer(input, key);
382:
383: // Must handle the case where the input string begins with the key
384: if (input.startsWith(key))
385: sb = sb.append(replacement);
386: while (st.hasMoreTokens()) {
387: sb = sb.append(st.nextToken());
388: if (st.hasMoreTokens())
389: sb = sb.append(replacement);
390: }
391: if (sb.length() >= 1)
392: return sb.toString();
393: else
394: return input;
395: }
396:
1.3 barstow 397: /*
398: * Print the document's header info
399: *
400: *@param out the servlet's output stream
401: */
1.1 barstow 402: private void printDocumentHeader (ServletOutputStream out) {
403:
404: try {
405:
406: out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.0 Transitional//EN\"");
407: out.println(" \"http://www.w3.org/TR/REC-html40/loose.dtd\">");
408: out.println("<HTML><HEAD>");
409: out.println("<TITLE>RDF creation</TITLE>");
410: out.println("<LINK HREF=\"rdf.css\" REL=\"stylesheet\">");
411: out.println("</HEAD>");
412: out.println("<BODY>");
413:
414: } catch (Exception e) {
1.2 barstow 415: System.err.println("Exception: " + e.getMessage());
1.1 barstow 416: }
417: }
418:
1.3 barstow 419: /*
420: * Print the rdf listing
421: *
422: *@param out the servlet's output stream
423: *@param rdf the RDF code
424: */
1.16 barstow 425: private void printListing (ServletOutputStream out, String rdf, boolean needCR) {
1.1 barstow 426: try {
427: out.println("<hr title=\"original source\">");
428: out.println("<h3>The original RDF/XML document</h3>");
429: out.println("<pre>");
430:
1.2 barstow 431: String s = replaceString(rdf, "<", "<");
432: StringTokenizer st = new StringTokenizer(s, "\n");
1.1 barstow 433:
434: // Now output the RDF one line at a time with line numbers
435: int lineNum = 1;
436: while (st.hasMoreTokens()) {
1.16 barstow 437: if (needCR)
438: out.print ("<a name=\"" + lineNum + "\">" + lineNum +
439: "</a>: " + st.nextToken() + "\n");
440: else
441: out.print ("<a name=\"" + lineNum + "\">" + lineNum +
442: "</a>: " + st.nextToken());
1.1 barstow 443: lineNum++;
444: }
445:
446: out.println("</pre>");
447: } catch (Exception e) {
448: System.err.println("Exception: " + e.getMessage());
449: }
450: }
451:
1.3 barstow 452: /*
453: * Print the header for the triple listing
454: *
455: *@param out the servlet's output stream
456: */
1.17 ! barstow 457: private void printTripleTableHeader (ServletOutputStream out) {
1.1 barstow 458: try {
459: out.println("<hr title=\"triples\">");
460: out.println("<h3>Triples of the data model</h3>");
1.17 ! barstow 461: out.println("<table border><tr>" +
! 462: "<td><b>Number</b></td>" +
! 463: "<td><b>Subject</b></td>" +
! 464: "<td><b>Predicate</b></td>" +
! 465: "<td><b>Object</b></td>" +
! 466: "</tr>");
1.1 barstow 467: } catch (Exception e) {
468: System.err.println("Exception: " + e.getMessage());
469: }
470: }
471:
1.3 barstow 472: /*
473: * Print the footer info for the triple listing
474: *
475: *@param out the servlet's output stream
476: */
1.17 ! barstow 477: private void printTripleTableFooter (ServletOutputStream out, SiRPACServletDumpConsumer consumer) {
1.1 barstow 478: try {
1.17 ! barstow 479: out.println("</table>");
1.14 barstow 480: if (consumer != null)
481: out.println("<p>The number of triples = " + consumer.getNumStatements() + "</p>");
1.1 barstow 482: } catch (Exception e) {
483: System.err.println("Exception: " + e.getMessage());
484: }
485: }
1.3 barstow 486:
487: /*
488: * Print the document's footer info
489: *
490: *@param out the servlet's output stream
491: *@param rdf the RDF code
492: */
1.1 barstow 493: private void printDocumentFooter (ServletOutputStream out, String rdf) {
494: try {
495:
496: out.println("<hr title=\"Problem reporting\">");
497: out.println("<h3>Feedback</h3>");
1.2 barstow 498: out.println("<p>If you suspect that SiRPAC produced an error, please enter an explanation below and then press the <b>Submit problem report</b> button, to mail the report (and listing) to <i>" + MAIL_TO + "</i></p>");
1.1 barstow 499: out.println("<form enctype=\"text/plain\" method=\"post\" action=\"mailto:" + MAIL_TO + "\">");
500: out.println("<textarea cols=\"60\" rows=\"4\" name=\"report\"></textarea>");
1.2 barstow 501: out.println("<p><input type=\"hidden\" name=\"RDF\" value=\"<?xml version="1.0"?>");
1.1 barstow 502:
1.2 barstow 503: // The listing is being passed as a parameter so the '<'
504: // and '"' characters must be replaced with < and ",
505: // respectively
1.16 barstow 506: if (rdf != null) {
507: String s1 = replaceString(rdf, "<", "<");
508: String s2 = replaceString(s1, "\"", """);
509: out.println(s2 + "\">");
510: }
1.1 barstow 511:
512: out.println("<input type=\"submit\" value=\"Submit problem report\">");
513: out.println("</form>");
1.13 barstow 514: out.println("<hr/>");
1.1 barstow 515: out.println("</BODY>");
516: out.println("</HTML>");
517:
518: } catch (Exception e) {
1.2 barstow 519: System.err.println("Exception: " + e.getMessage());
1.1 barstow 520: }
521:
522: }
523:
1.3 barstow 524: /*
1.16 barstow 525: * Given a URI string, open it, read its contents into a String
526: * and return the String
527: *
528: *@param uri the URI to open
529: *@return the content at the URI or null if any error occurs
530: */
531: private String getByteStream (String uri) {
532: try {
533: URL url = new URL(uri);
534: InputStream is = url.openStream();
535: String s = new String("");
536:
537: int c;
538: int numRead = 0;
539:
540: while ((c = is.read()) != -1) {
541: s += (char)c;
542: if (numRead == 15) {
543: // A server could return content but not the RDF/XML that
544: // we need. Check the beginning of s and if it looks like
545: // a generic HTML message, return an error.
546: if (s.startsWith("<!DOCTYPE HTML"))
547: return null;
548: }
549: numRead++;
550: }
551:
552: if (s.equals(""))
553: // Nothing was returned
554: return null;
555:
556: return s;
557:
558: } catch (Exception e) {
559: return null;
560: }
561: }
562:
563: /*
1.3 barstow 564: * Servlet's get info method
565: */
1.1 barstow 566: public String getServletInfo () {
567: return "Servlet Wrapper for SiRPAC. This is revision " + REVISION;
568: }
569:
1.3 barstow 570: /*
571: * Servlet's init method
572: *
573: *@param config the servlet's configuration object
574: */
1.1 barstow 575: public void init(ServletConfig config) throws ServletException {
576: super.init (config);
577:
578: m_sirpac = new SiRPAC();
579: m_errorHandler = new ErrorStore();
1.3 barstow 580: m_sirpac.setErrorHandler(m_errorHandler);
1.1 barstow 581:
1.3 barstow 582: // Cache the parameters
583: m_SiRPACTmpDir = config.getInitParameter(SIRPAC_TMP_DIR);
1.5 barstow 584:
585: // All of the Graph Viz paths extend from GRAPH_VIZ_ROOT
586: String GraphVizRoot = config.getInitParameter(GRAPH_VIZ_ROOT);
587:
588: m_GraphVizPath = GraphVizRoot + "/" + config.getInitParameter(GRAPH_VIZ_PATH);
589: m_GraphVizFontDir = GraphVizRoot + "/" + config.getInitParameter(GRAPH_VIZ_FONT_DIR);
590: m_GraphVizLibDir = GraphVizRoot + "/" + config.getInitParameter(GRAPH_VIZ_LIB_DIR);
1.1 barstow 591: }
592:
1.3 barstow 593: /*
594: * Servlet's destroy info method
595: */
1.1 barstow 596: public void destroy () {
597: super.destroy ();
598: }
599:
1.3 barstow 600: /*
1.4 barstow 601: * Servlet's doGet info method - NOT supported
1.3 barstow 602: *
603: *@param req the request
604: *@param res the response
605: */
1.1 barstow 606: public void doGet (HttpServletRequest req, HttpServletResponse res)
607: throws ServletException, IOException {
1.3 barstow 608:
1.1 barstow 609: ServletOutputStream out = res.getOutputStream ();
610:
611: res.setContentType ("text/html");
612:
1.3 barstow 613: out.println ("<h1>GET is NOT supported!</h1>\n\n<p>Please send RDF through POST!</p>\n");
1.1 barstow 614: }
615:
1.3 barstow 616: /*
617: * Servlet's doPost method
618: *
619: *@param req the request
620: *@param res the response
621: */
1.1 barstow 622: public void doPost (HttpServletRequest req, HttpServletResponse res)
623: throws ServletException, IOException {
624:
625: ServletOutputStream out = res.getOutputStream ();
626:
1.16 barstow 627: String sRDF = req.getParameter (POST_TEXT);
628: String sBags = req.getParameter (POST_BAG);
629: String sStreamMode = req.getParameter (POST_STREAM_MODE);
630: String sSaveRDF = req.getParameter (POST_SAVE_RDF);
631: String sURI = req.getParameter (POST_URI);
632:
633: InputSource is = null;
634:
635: boolean error = false;
636: String sError = null;
637:
1.1 barstow 638: SiRPACServletDumpConsumer consumer = new SiRPACServletDumpConsumer();
1.9 barstow 639:
640: // Re-initialize the parser
641: m_sirpac = new SiRPAC();
642: m_errorHandler = new ErrorStore();
643: m_sirpac.setErrorHandler(m_errorHandler);
1.1 barstow 644:
1.16 barstow 645: // If a URI was sent in the request, it takes precedence
646: if (sURI != null && sURI.length() >= 1) {
647: try {
648: is = GenericParser.getInputSource(sURI);
649: sRDF = getByteStream(sURI);
650: if (sRDF == null)
651: sError = "An attempt to load the RDF from URI '" + sURI + "' failed. (The file may not exist or the server is down.)";
652: } catch (MalformedURLException e) {
653: sError = "An attempt to load URI '" + sURI
654: + "' produced a MalforedURL Exception.\n["
655: + e.getMessage() + "]";
656: } catch (IOException e) {
657: sError = "An attempt to load URI '" + sURI
658: + "' produced an IO Exception.\n["
659: + e.getMessage() + "]";
660: }
661: } else {
662: StringReader sr = new StringReader (sRDF);
663: is = new InputSource (sr);
664: }
665:
666: if (sError != null) {
667: printDocumentHeader (out);
668: out.println ("<h1>" + sError + "</h1>\n");
669: printDocumentFooter(out, null);
670: return;
671: }
672:
1.1 barstow 673: printDocumentHeader (out);
1.16 barstow 674: printListing (out, sRDF, sURI != null && sURI.length() >= 1);
1.17 ! barstow 675: printTripleTableHeader (out);
1.1 barstow 676:
677: try {
1.3 barstow 678: // Override the default triple output handler
1.1 barstow 679: consumer.setOutputStream(out);
680:
1.6 barstow 681: // Toggle Bag handling - always false unless explicitly
682: // included in the request
683: m_sirpac.createBags (false);
1.1 barstow 684: if (sBags != null && sBags.equals ("on"))
685: m_sirpac.createBags (true);
1.10 barstow 686:
687: // Set parser's streaming mode
1.11 barstow 688: if (sStreamMode != null && sStreamMode.equals ("on"))
1.10 barstow 689: m_sirpac.setStreamMode (false);
1.1 barstow 690:
691: m_sirpac.parse(is, consumer);
692:
1.17 ! barstow 693: printTripleTableFooter(out, consumer);
1.12 barstow 694:
1.14 barstow 695: generateGraph(out, sRDF, req, (sSaveRDF != null) ? true : false);
1.2 barstow 696:
1.1 barstow 697: } catch (SAXException e) {
1.3 barstow 698: error = true;
1.1 barstow 699: } catch (Exception e) {
1.3 barstow 700: error = true;
1.1 barstow 701: e.printStackTrace ();
702: }
703:
704: res.setContentType ("text/html");
1.3 barstow 705:
706: if (error) {
1.17 ! barstow 707: printTripleTableFooter(out, null);
1.1 barstow 708: out.println ("<h1>Errors during parsing</h1>\n");
709: out.println ("<pre>\n");
1.2 barstow 710:
711: // Make the line number a link to the listing
1.1 barstow 712: out.println ("Fatal error: " + m_errorHandler.getErrorMessage());
713: out.println (" (Line number = " + "<a href=\"#" +
714: m_errorHandler.getLineNumber() + "\">" +
715: m_errorHandler.getLineNumber() + "</a>" +
716: ", Column number = " +
717: m_errorHandler.getColumnNumber() + ")");
718:
719: out.println ("</pre>\n\n");
720: }
721:
722: printDocumentFooter(out, sRDF);
723: }
724: }
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