From dcfc32803c12692d28ca484b687ab37d7f9af997 Mon Sep 17 00:00:00 2001
From: brianjlowe <brianjlowe@440791e1-c2bf-4c1e-ad7c-caf3f8b0ebe8>
Date: Mon, 25 Jun 2012 20:57:52 +0000
Subject: [PATCH] better error messages if remote SPARQL endpoint is
 unavailable

---
 .../rdfservice/impl/sparql/RDFServiceSparql.java  | 15 +++++++++++++++
 .../webapp/servlet/setup/WebappDaoSetup.java      |  3 +++
 2 files changed, 18 insertions(+)

diff --git a/webapp/src/edu/cornell/mannlib/vitro/webapp/rdfservice/impl/sparql/RDFServiceSparql.java b/webapp/src/edu/cornell/mannlib/vitro/webapp/rdfservice/impl/sparql/RDFServiceSparql.java
index 4ddcfbfb6..9d6773d1c 100644
--- a/webapp/src/edu/cornell/mannlib/vitro/webapp/rdfservice/impl/sparql/RDFServiceSparql.java
+++ b/webapp/src/edu/cornell/mannlib/vitro/webapp/rdfservice/impl/sparql/RDFServiceSparql.java
@@ -10,6 +10,7 @@ import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
 
+import org.apache.commons.httpclient.HttpException;
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -77,6 +78,20 @@ public class RDFServiceSparql extends RDFServiceImpl implements RDFService {
         this.updateEndpointURI = updateEndpointURI;
         this.readRepository = new HTTPRepository(readEndpointURI);
         this.updateRepository = new HTTPRepository(updateEndpointURI);
+        
+        testConnection();
+    }
+    
+    private void testConnection() {
+        try {
+            this.sparqlSelectQuery(
+                    "SELECT ?s WHERE { ?s a " +
+                    "<http://vitro.mannlib.cornell.edu/ns/vitro/nonsense/> }", 
+                            RDFService.ResultFormat.JSON);
+        } catch (Exception e) {
+            throw new RuntimeException("Unable to connect to endpoint at " + 
+                    readEndpointURI, e);
+        }
     }
  
     /**
diff --git a/webapp/src/edu/cornell/mannlib/vitro/webapp/servlet/setup/WebappDaoSetup.java b/webapp/src/edu/cornell/mannlib/vitro/webapp/servlet/setup/WebappDaoSetup.java
index 5e30a3870..c16d80c09 100644
--- a/webapp/src/edu/cornell/mannlib/vitro/webapp/servlet/setup/WebappDaoSetup.java
+++ b/webapp/src/edu/cornell/mannlib/vitro/webapp/servlet/setup/WebappDaoSetup.java
@@ -133,6 +133,7 @@ public class WebappDaoSetup extends JenaDataSourceSetupBase
             baseOms.setTBoxModel(tboxAssertions);
         } catch (Throwable e) {
             log.error("Unable to load tbox assertion cache from DB", e);
+            throw new RuntimeException(e);
         }
         
         // TBox inferences
@@ -155,6 +156,7 @@ public class WebappDaoSetup extends JenaDataSourceSetupBase
             inferenceOms.setTBoxModel(tboxInferences);
         } catch (Throwable e) {
             log.error("Unable to load tbox inference cache from DB", e);
+            throw new RuntimeException(e);
         }
                               
         // union ABox
@@ -204,6 +206,7 @@ public class WebappDaoSetup extends JenaDataSourceSetupBase
         } catch (Throwable e) {
             log.error("Unable to load application metadata model cache from DB"
                     , e);
+            throw new RuntimeException(e);
         }
         
         checkForNamespaceMismatch( baseOms.getApplicationMetadataModel(), ctx );