dataSource : config.getDataSources().entrySet()) {
dataSources.put(dataSource.getKey(), DataSourceFactory.create(dataSource.getValue()));
}
-
- // register content types
+ // register content types
mimeTypes.add(Lang.TTL.getHeaderString());
mimeTypes.add(Lang.JSONLD.getHeaderString());
mimeTypes.add(Lang.NTRIPLES.getHeaderString());
mimeTypes.add(Lang.RDFXML.getHeaderString() );
- } catch (Exception e) {
+ } catch (IOException | DataSourceException e) {
throw new ServletException(e);
}
}
+ /**
+ * Get the datasource
+ *
+ * @param request
+ * @return
+ * @throws IOException
+ */
+ private IDataSource getDataSource(HttpServletRequest request) throws IOException {
+ String contextPath = request.getContextPath();
+ String requestURI = request.getRequestURI();
+
+ String path = contextPath == null
+ ? requestURI
+ : requestURI.substring(contextPath.length());
+ String dataSourceName = path.substring(1);
+ IDataSource dataSource = dataSources.get(dataSourceName);
+ if (dataSource == null) {
+ throw new IOException("Data source not found.");
+ }
+ return dataSource;
+ }
+
+ /**
+ * Get dataset url
+ *
+ * @param request
+ * @return
+ */
+ private String getDatasetUrl(HttpServletRequest request) {
+ String hostName = request.getHeader(HttpHeaders.SERVER);
+ if (hostName == null) {
+ hostName = request.getServerName();
+ }
+ return request.getScheme() + "://" + hostName + request.getRequestURI();
+ }
+
+ /**
+ * Add total and limit
+ *
+ * @param output
+ * @param fragmentId
+ * @param total
+ * @param limit
+ */
+ private void addMeta(Model output, Resource datasetId, Resource fragmentId,
+ long total, long limit) {
+ output.add(datasetId, CommonResources.RDF_TYPE, CommonResources.VOID_DATASET);
+ output.add(datasetId, CommonResources.RDF_TYPE, CommonResources.HYDRA_COLLECTION);
+ output.add(datasetId, CommonResources.VOID_SUBSET, fragmentId);
+
+ output.add(fragmentId, CommonResources.RDF_TYPE, CommonResources.HYDRA_COLLECTION);
+ output.add(fragmentId, CommonResources.RDF_TYPE, CommonResources.HYDRA_PAGEDCOLLECTION);
+
+ Literal totalTyped = output.createTypedLiteral(total, XSDDatatype.XSDinteger);
+ Literal limitTyped = output.createTypedLiteral(limit, XSDDatatype.XSDinteger);
+
+ output.add(fragmentId, CommonResources.VOID_TRIPLES, totalTyped);
+ output.add(fragmentId, CommonResources.HYDRA_TOTALITEMS, totalTyped);
+ output.add(fragmentId, CommonResources.HYDRA_ITEMSPERPAGE, limitTyped);
+ }
+
+
+ /**
+ * Add reference to first/previous/next page
+ *
+ * @param output
+ * @param fragmentId
+ * @param fragmentUrl
+ * @param total
+ * @param limit
+ * @param offset
+ * @param page
+ * @throws URISyntaxException
+ */
+ private void addPages(Model output, Resource fragmentId, String fragmentUrl,
+ long total, long limit, long offset, long page) throws URISyntaxException {
+ URIBuilder pagedUrl = new URIBuilder(fragmentUrl);
+
+ pagedUrl.setParameter(PAGE, "1");
+ output.add(fragmentId, CommonResources.HYDRA_FIRSTPAGE,
+ output.createResource(pagedUrl.toString()));
+ if (offset > 0) {
+ pagedUrl.setParameter(PAGE, Long.toString(page - 1));
+ output.add(fragmentId, CommonResources.HYDRA_PREVIOUSPAGE,
+ output.createResource(pagedUrl.toString()));
+ }
+ if (offset + limit < total) {
+ pagedUrl.setParameter(PAGE, Long.toString(page + 1));
+ output.add(fragmentId, CommonResources.HYDRA_NEXTPAGE,
+ output.createResource(pagedUrl.toString()));
+ }
+ }
+
+ /**
+ * Add controls to output
+ *
+ * @param output
+ * @param datasetId
+ * @param datasetUrl
+ */
+ private void addControls(Model output, Resource datasetId, String datasetUrl) {
+ // add controls
+ Resource triplePattern = output.createResource();
+ Resource subjectMapping = output.createResource();
+ Resource predicateMapping = output.createResource();
+ Resource objectMapping = output.createResource();
+
+ output.add(datasetId, CommonResources.HYDRA_SEARCH, triplePattern);
+ output.add(triplePattern, CommonResources.HYDRA_TEMPLATE, output.createLiteral(datasetUrl + "{?subject,predicate,object}"));
+ output.add(triplePattern, CommonResources.HYDRA_MAPPING, subjectMapping);
+ output.add(triplePattern, CommonResources.HYDRA_MAPPING, predicateMapping);
+ output.add(triplePattern, CommonResources.HYDRA_MAPPING, objectMapping);
+
+ output.add(subjectMapping, CommonResources.HYDRA_VARIABLE, output.createLiteral(SUBJ));
+ output.add(subjectMapping, CommonResources.HYDRA_PROPERTY, CommonResources.RDF_SUBJECT);
+
+ output.add(predicateMapping, CommonResources.HYDRA_VARIABLE, output.createLiteral(PRED));
+ output.add(predicateMapping, CommonResources.HYDRA_PROPERTY, CommonResources.RDF_PREDICATE);
+ output.add(objectMapping, CommonResources.HYDRA_VARIABLE, output.createLiteral(OBJ));
+
+ output.add(objectMapping, CommonResources.HYDRA_PROPERTY, CommonResources.RDF_OBJECT);
+ }
+
+
@Override
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException {
try {
- // find the data source
- final String contextPath = request.getContextPath();
- final String requestURI = request.getRequestURI();
- final String path = contextPath == null ? requestURI : requestURI.substring(contextPath.length());
- final String query = request.getQueryString();
- final String dataSourceName = path.substring(1);
- final IDataSource dataSource = dataSources.get(dataSourceName);
- if (dataSource == null) {
- throw new Exception("Data source not found.");
- }
-
+ IDataSource dataSource = getDataSource(request);
+
// query the fragment
- final Resource subject = parseAsResource(request.getParameter("subject"));
- final Property predicate = parseAsProperty(request.getParameter("predicate"));
- final RDFNode object = parseAsNode(request.getParameter("object"));
- final long page = Math.max(1, parseAsInteger(request.getParameter("page")));
- final long limit = TRIPLESPERPAGE, offset = limit * (page - 1);
- final TriplePatternFragment fragment = dataSource.getFragment(subject, predicate, object, offset, limit);
+ Resource subject = parseAsResource(request.getParameter(SUBJ));
+ Property predicate = parseAsProperty(request.getParameter(PRED));
+ RDFNode object = parseAsNode(request.getParameter(OBJ));
+
+ long page = Math.max(1, parseAsInteger(request.getParameter(PAGE)));
+ long limit = TRIPLESPERPAGE;
+ long offset = limit * (page - 1);
+
+ TriplePatternFragment fragment =
+ dataSource.getFragment(subject, predicate, object, offset, limit);
// fill the output model
- final Model output = fragment.getTriples();
+ Model output = fragment.getTriples();
output.setNsPrefixes(config.getPrefixes());
// do conneg
@@ -128,54 +270,26 @@ public void doGet(HttpServletRequest request, HttpServletResponse response) thro
RDFDataMgr.write(response.getOutputStream(), output, contentType);
// add dataset metadata
- final String hostName = request.getHeader("Host");
- final String datasetUrl = request.getScheme() + "://"
- + (hostName == null ? request.getServerName() : hostName) + request.getRequestURI();
- final String fragmentUrl = query == null ? datasetUrl : (datasetUrl + "?" + query);
- final Resource datasetId = output.createResource(datasetUrl + "#dataset");
- final Resource fragmentId = output.createResource(fragmentUrl);
- output.add(datasetId, RDF_TYPE, VOID_DATASET);
- output.add(datasetId, RDF_TYPE, HYDRA_COLLECTION);
- output.add(datasetId, VOID_SUBSET, fragmentId);
-
- // add fragment metadata
- output.add(fragmentId, RDF_TYPE, HYDRA_COLLECTION);
- output.add(fragmentId, RDF_TYPE, HYDRA_PAGEDCOLLECTION);
- final Literal total = output.createTypedLiteral(fragment.getTotalSize(), XSDDatatype.XSDinteger);
- output.add(fragmentId, VOID_TRIPLES, total);
- output.add(fragmentId, HYDRA_TOTALITEMS, total);
- output.add(fragmentId, HYDRA_ITEMSPERPAGE, output.createTypedLiteral(limit, XSDDatatype.XSDinteger));
-
- // add pages
- final URIBuilder pagedUrl = new URIBuilder(fragmentUrl);
- pagedUrl.setParameter("page", "1");
- output.add(fragmentId, HYDRA_FIRSTPAGE, output.createResource(pagedUrl.toString()));
- if (offset > 0) {
- pagedUrl.setParameter("page", Long.toString(page - 1));
- output.add(fragmentId, HYDRA_PREVIOUSPAGE, output.createResource(pagedUrl.toString()));
- }
- if (offset + limit < fragment.getTotalSize()) {
- pagedUrl.setParameter("page", Long.toString(page + 1));
- output.add(fragmentId, HYDRA_NEXTPAGE, output.createResource(pagedUrl.toString()));
- }
+ String datasetUrl = getDatasetUrl(request);
+ Resource datasetId = output.createResource(datasetUrl + "#dataset");
+
+ String query = request.getQueryString();
+ String fragmentUrl = query == null ? datasetUrl : (datasetUrl + "?" + query);
+ Resource fragmentId = output.createResource(fragmentUrl);
- // add controls
- final Resource triplePattern = output.createResource();
- final Resource subjectMapping = output.createResource();
- final Resource predicateMapping = output.createResource();
- final Resource objectMapping = output.createResource();
- output.add(datasetId, HYDRA_SEARCH, triplePattern);
- output.add(triplePattern, HYDRA_TEMPLATE, output.createLiteral(datasetUrl + "{?subject,predicate,object}"));
- output.add(triplePattern, HYDRA_MAPPING, subjectMapping);
- output.add(triplePattern, HYDRA_MAPPING, predicateMapping);
- output.add(triplePattern, HYDRA_MAPPING, objectMapping);
- output.add(subjectMapping, HYDRA_VARIABLE, output.createLiteral("subject"));
- output.add(subjectMapping, HYDRA_PROPERTY, RDF_SUBJECT);
- output.add(predicateMapping, HYDRA_VARIABLE, output.createLiteral("predicate"));
- output.add(predicateMapping, HYDRA_PROPERTY, RDF_PREDICATE);
- output.add(objectMapping, HYDRA_VARIABLE, output.createLiteral("object"));
- output.add(objectMapping, HYDRA_PROPERTY, RDF_OBJECT);
- } catch (Exception e) {
+ long total = fragment.getTotalSize();
+
+ addMeta(output, datasetId, fragmentId, total, limit);
+ addPages(output, fragmentId, fragmentUrl, total, limit, offset, page);
+ addControls(output, datasetId, datasetUrl);
+
+ // serialize the output as Turtle
+ response.setHeader(HttpHeaders.SERVER, "Linked Data Fragments Server");
+ response.setContentType("text/turtle");
+ response.setCharacterEncoding(CharEncoding.UTF_8);
+
+ output.write(response.getWriter(), "Turtle", fragmentUrl);
+ } catch (IOException | URISyntaxException e) {
throw new ServletException(e);
}
}
@@ -201,8 +315,10 @@ private int parseAsInteger(String value) {
* @return the parsed value, or null if unspecified
*/
private Resource parseAsResource(String value) {
- final RDFNode subject = parseAsNode(value);
- return subject == null || subject instanceof Resource ? (Resource) subject : INVALID_URI;
+ RDFNode subject = parseAsNode(value);
+ return subject == null || subject instanceof Resource
+ ? (Resource) subject
+ : CommonResources.INVALID_URI;
}
/**
@@ -212,15 +328,15 @@ private Resource parseAsResource(String value) {
* @return the parsed value, or null if unspecified
*/
private Property parseAsProperty(String value) {
- final RDFNode predicateNode = parseAsNode(value);
+ RDFNode predicateNode = parseAsNode(value);
if (predicateNode instanceof Resource) {
try {
return ResourceFactory.createProperty(((Resource) predicateNode).getURI());
} catch (InvalidPropertyURIException ex) {
- return INVALID_URI;
+ return CommonResources.INVALID_URI;
}
}
- return predicateNode == null ? null : INVALID_URI;
+ return predicateNode == null ? null : CommonResources.INVALID_URI;
}
/**
@@ -231,11 +347,11 @@ private Property parseAsProperty(String value) {
*/
private RDFNode parseAsNode(String value) {
// nothing or empty indicates an unknown
- if (value == null || value.length() == 0) {
+ if (value == null || value.isEmpty()) {
return null;
}
// find the kind of entity based on the first character
- final char firstChar = value.charAt(0);
+ char firstChar = value.charAt(0);
switch (firstChar) {
// variable or blank node indicates an unknown
case '?':
@@ -246,20 +362,20 @@ private RDFNode parseAsNode(String value) {
return ResourceFactory.createResource(value.substring(1, value.length() - 1));
// quotes indicate a string
case '"':
- final Matcher matcher = STRINGPATTERN.matcher(value);
+ Matcher matcher = STRINGPATTERN.matcher(value);
if (matcher.matches()) {
- final String body = matcher.group(1);
- final String lang = matcher.group(2);
- final String type = matcher.group(3);
+ String body = matcher.group(1);
+ String lang = matcher.group(2);
+ String type = matcher.group(3);
if (lang != null) {
return ResourceFactory.createLangLiteral(body, lang);
}
if (type != null) {
- return ResourceFactory.createTypedLiteral(body, types.getSafeTypeByName(type));
+ return ResourceFactory.createTypedLiteral(body, TYPES.getSafeTypeByName(type));
}
return ResourceFactory.createPlainLiteral(body);
}
- return INVALID_URI;
+ return CommonResources.INVALID_URI;
// assume it's a URI without angular brackets
default:
return ResourceFactory.createResource(value);
diff --git a/src/org/linkeddatafragments/standalone/JettyServer.java b/src/org/linkeddatafragments/standalone/JettyServer.java
index 6d59d07..23ff9c1 100644
--- a/src/org/linkeddatafragments/standalone/JettyServer.java
+++ b/src/org/linkeddatafragments/standalone/JettyServer.java
@@ -1,9 +1,15 @@
package org.linkeddatafragments.standalone;
-import org.apache.commons.cli.*;
+import org.apache.commons.cli.CommandLine;
+import org.apache.commons.cli.CommandLineParser;
+import org.apache.commons.cli.DefaultParser;
+import org.apache.commons.cli.HelpFormatter;
+import org.apache.commons.cli.Options;
+
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.servlet.ServletHandler;
import org.eclipse.jetty.servlet.ServletHolder;
+
import org.linkeddatafragments.servlet.TriplePatternFragmentServlet;
/**
@@ -16,64 +22,58 @@
* need for a separate servlet container such as Tomcat.
*
*
- * Copyright 2014 MMLab, UGent
*
* @author Gerald Haesendonck
* @author Miel Vander Sande
+ * @author Bart Hanssens
*/
public class JettyServer {
-
+ private static void printHelp(Options options) {
+ HelpFormatter formatter = new HelpFormatter();
+ formatter.printHelp(JettyServer.class.getName() + " [config-example.json] []",
+ "Starts a standalone LDF Triple Pattern server. Options:", options, "");
+ }
+
public static void main(String[] args) throws Exception {
Options options = new Options();
options.addOption("h", "help", false, "Print this help message and then exit.");
options.addOption("p", "port", true, "The port the server listents to. The default is 8080.");
- boolean printHelp = false;
- CommandLineParser parser = new BasicParser();
- try {
- CommandLine commandLine = parser.parse(options, args);
+
+ CommandLineParser parser = new DefaultParser();
+ CommandLine commandLine = parser.parse(options, args);
- String config = null;
- if (!commandLine.getArgList().isEmpty()) {
- config = commandLine.getArgs()[0];
- }
-
- if (commandLine.hasOption('h')) {
- printHelp = true;
- return;
- }
- int port;
- if (commandLine.hasOption('p')) {
- port = Integer.parseInt(commandLine.getOptionValue('p'));
- } else {
- port = 8080;
- }
+ String config = null;
+ if (!commandLine.getArgList().isEmpty()) {
+ config = commandLine.getArgs()[0];
+ }
- // create a new (Jetty) server, and add a servlet handler
- Server server = new Server(port);
- ServletHandler handler = new ServletHandler();
- server.setHandler(handler);
+ if (config == null || commandLine.hasOption('h')) {
+ printHelp(options);
+ System.exit(-1);
+ }
+
+ int port = 8080;
+ if (commandLine.hasOption('p')) {
+ port = Integer.parseInt(commandLine.getOptionValue('p'));
+ }
- // add the TriplePatternFragmentsServlet to the handler
- ServletHolder tpfServletHolder = new ServletHolder(new TriplePatternFragmentServlet());
- tpfServletHolder.setInitParameter("configFile", config);
- handler.addServletWithMapping(tpfServletHolder, "/*");
+ // create a new (Jetty) server, and add a servlet handler
+ Server server = new Server(port);
+ ServletHandler handler = new ServletHandler();
+ server.setHandler(handler);
- // start the server
- server.start();
- System.out.println("Started server, listening at port " + port);
+ // add the TriplePatternFragmentsServlet to the handler
+ ServletHolder tpfServletHolder = new ServletHolder(new TriplePatternFragmentServlet());
+ tpfServletHolder.setInitParameter(TriplePatternFragmentServlet.CFGFILE, config);
+ handler.addServletWithMapping(tpfServletHolder, "/*");
- // The use of server.join() the will make the current thread join and wait until the server is done executing.
- // See http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html#join()
- server.join();
- } catch (ParseException e) {
- System.out.println(e.getMessage());
- printHelp = true;
+ // start the server
+ server.start();
+ System.out.println("Started server, listening at port " + port);
- } finally {
- if (printHelp) {
- HelpFormatter formatter = new HelpFormatter();
- formatter.printHelp(JettyServer.class.getName() + " [config-example.json] []", "Starts a standalone LDF Trpile Pattern server. Options:", options, "");
- }
- }
+ // The use of server.join() the will make the current thread join and wait until the server is done executing.
+ // See http://docs.oracle.com/javase/7/docs/api/java/lang/Thread.html#join()
+ server.join();
}
}
diff --git a/src/org/linkeddatafragments/util/CommonResources.java b/src/org/linkeddatafragments/util/CommonResources.java
index f7b4f2c..150ca17 100644
--- a/src/org/linkeddatafragments/util/CommonResources.java
+++ b/src/org/linkeddatafragments/util/CommonResources.java
@@ -5,35 +5,35 @@
@SuppressWarnings("javadoc")
public class CommonResources {
- public final static String RDF = "http://www.w3.org/1999/02/22-rdf-syntax-ns#";
- public final static Property RDF_TYPE = createProperty(RDF + "type");
- public final static Property RDF_SUBJECT = createProperty(RDF + "subject");
- public final static Property RDF_PREDICATE = createProperty(RDF + "predicate");
- public final static Property RDF_OBJECT = createProperty(RDF + "object");
-
- public final static String VOID = "http://rdfs.org/ns/void#";
- public final static Property VOID_TRIPLES = createProperty(VOID + "triples");
- public final static Property VOID_SUBSET = createProperty(VOID + "subset");
- public final static Property VOID_DATASET = createProperty(VOID + "Dataset");
-
- public final static String HYDRA = "http://www.w3.org/ns/hydra/core#";
- public final static Property HYDRA_TOTALITEMS = createProperty(HYDRA + "totalItems");
- public final static Property HYDRA_ITEMSPERPAGE = createProperty(HYDRA + "itemsPerPage");
- public final static Property HYDRA_SEARCH = createProperty(HYDRA + "search");
- public final static Property HYDRA_TEMPLATE = createProperty(HYDRA + "template");
- public final static Property HYDRA_MAPPING = createProperty(HYDRA + "mapping");
- public final static Property HYDRA_VARIABLE = createProperty(HYDRA + "variable");
- public final static Property HYDRA_PROPERTY = createProperty(HYDRA + "property");
- public final static Property HYDRA_COLLECTION = createProperty(HYDRA + "Collection");
- public final static Property HYDRA_PAGEDCOLLECTION = createProperty(HYDRA + "PagedCollection");
- public final static Property HYDRA_FIRSTPAGE = createProperty(HYDRA + "firstPage");
- public final static Property HYDRA_LASTPAGE = createProperty(HYDRA + "lastPage");
- public final static Property HYDRA_NEXTPAGE = createProperty(HYDRA + "nextPage");
- public final static Property HYDRA_PREVIOUSPAGE = createProperty(HYDRA + "previousPage");
-
- public final static Property INVALID_URI = createProperty("urn:invalid");
-
- private static Property createProperty(String uri) {
- return ResourceFactory.createProperty(uri);
- }
+ public final static String RDF = "http://www.w3.org/1999/02/22-rdf-syntax-ns#";
+ public final static Property RDF_TYPE = createProperty(RDF + "type");
+ public final static Property RDF_SUBJECT = createProperty(RDF + "subject");
+ public final static Property RDF_PREDICATE = createProperty(RDF + "predicate");
+ public final static Property RDF_OBJECT = createProperty(RDF + "object");
+
+ public final static String VOID = "http://rdfs.org/ns/void#";
+ public final static Property VOID_TRIPLES = createProperty(VOID + "triples");
+ public final static Property VOID_SUBSET = createProperty(VOID + "subset");
+ public final static Property VOID_DATASET = createProperty(VOID + "Dataset");
+
+ public final static String HYDRA = "http://www.w3.org/ns/hydra/core#";
+ public final static Property HYDRA_TOTALITEMS = createProperty(HYDRA + "totalItems");
+ public final static Property HYDRA_ITEMSPERPAGE = createProperty(HYDRA + "itemsPerPage");
+ public final static Property HYDRA_SEARCH = createProperty(HYDRA + "search");
+ public final static Property HYDRA_TEMPLATE = createProperty(HYDRA + "template");
+ public final static Property HYDRA_MAPPING = createProperty(HYDRA + "mapping");
+ public final static Property HYDRA_VARIABLE = createProperty(HYDRA + "variable");
+ public final static Property HYDRA_PROPERTY = createProperty(HYDRA + "property");
+ public final static Property HYDRA_COLLECTION = createProperty(HYDRA + "Collection");
+ public final static Property HYDRA_PAGEDCOLLECTION = createProperty(HYDRA + "PagedCollection");
+ public final static Property HYDRA_FIRSTPAGE = createProperty(HYDRA + "firstPage");
+ public final static Property HYDRA_LASTPAGE = createProperty(HYDRA + "lastPage");
+ public final static Property HYDRA_NEXTPAGE = createProperty(HYDRA + "nextPage");
+ public final static Property HYDRA_PREVIOUSPAGE = createProperty(HYDRA + "previousPage");
+
+ public final static Property INVALID_URI = createProperty("urn:invalid");
+
+ private static Property createProperty(String uri) {
+ return ResourceFactory.createProperty(uri);
+ }
}