Send 404 when datasource is not found

Author: Miel Vander Sande

src/org/linkeddatafragments/exceptions/DataSourceNotFoundException.java

@@ -0,0 +1,19 @@
+package org.linkeddatafragments.exceptions;
+
+import org.linkeddatafragments.datasource.IDataSource;
+
+/**
+ *
+ * @author mielvandersande
+ */
+public class DataSourceNotFoundException extends Exception {
+    private static final long serialVersionUID = 1L;
+
+    public DataSourceNotFoundException(Throwable cause) {
+        super(cause.getMessage());
+    }
+
+    public DataSourceNotFoundException(String dataSourceName) {
+        super("Data source " + dataSourceName + " not found.");
+    }  
+}

src/org/linkeddatafragments/servlet/TriplePatternFragmentServlet.java

@@ -18,6 +18,8 @@
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.Map.Entry;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 import javax.servlet.ServletConfig;
@@ -37,6 +39,7 @@
 import org.linkeddatafragments.datasource.JenaTDBDataSourceType;
 import org.linkeddatafragments.datasource.TriplePatternFragment;
 import org.linkeddatafragments.exceptions.DataSourceException;
+import org.linkeddatafragments.exceptions.DataSourceNotFoundException;
 import org.linkeddatafragments.util.CommonResources;
 import org.linkeddatafragments.util.MIMEParse;
 
@@ -118,7 +121,7 @@ public void init(ServletConfig servletConfig) throws ServletException {
      * @return
      * @throws IOException
      */
-    private IDataSource getDataSource(HttpServletRequest request) throws IOException {
+    private IDataSource getDataSource(HttpServletRequest request) throws DataSourceNotFoundException {
         String contextPath = request.getContextPath();
         String requestURI = request.getRequestURI();
 
@@ -133,7 +136,7 @@ private IDataSource getDataSource(HttpServletRequest request) throws IOException
         String dataSourceName = path.substring(1);
         IDataSource dataSource = dataSources.get(dataSourceName);
         if (dataSource == null) {
-            throw new IOException("Data source not found.");
+            throw new DataSourceNotFoundException(dataSourceName);
         }
         return dataSource;
     }
@@ -299,8 +302,15 @@ public void doGet(HttpServletRequest request, HttpServletResponse response) thro
 
             RDFDataMgr.write(response.getOutputStream(), output, contentType);
         } catch (IOException | URISyntaxException e) {
-            e.printStackTrace();
             throw new ServletException(e);
+        } catch (DataSourceNotFoundException ex) {
+            try {
+                response.setStatus(404);
+                response.getOutputStream().println(ex.getMessage());
+                response.getOutputStream().close();
+            } catch (IOException ex1) {
+                throw new ServletException(ex1);
+            }
         }
     }