more verbose error messages

histream-import/src/main/java/de/sekmi/histream/etl/config/DataSource.java

@@ -6,6 +6,7 @@ import java.net.URL;
 import java.net.URLConnection;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Objects;
 
 import javax.xml.bind.JAXB;
 import javax.xml.bind.annotation.XmlAccessType;
@@ -28,7 +29,7 @@ import de.sekmi.histream.etl.ScriptProcessingQueue;
  * the location of the data source description.
  * 
  * @see JAXB#unmarshal(java.io.File, Class)
- * @author Raphael
+ * @author R.W.Majeed
  *
  */
 @XmlRootElement(name="datasource")
@@ -89,14 +90,22 @@ public class DataSource {
 			return Arrays.asList();
 		}
 	}
-	
-	public static DataSource load(URL configuration) throws IOException{
+	/**
+	 * Load the datasource configuration from the given URL.
+	 * @param configuration configuration URL
+	 * @return data source object
+	 * @throws IOException IO error
+	 * @throws NullPointerException /datasource or /datasource/meta missing
+	 */
+	public static DataSource load(URL configuration) throws IOException, NullPointerException{
 		URLConnection conn = configuration.openConnection();
 		conn.connect();
 		DataSource ds;
 		try( InputStream in = conn.getInputStream() ){
 			ds = JAXB.unmarshal(configuration, DataSource.class);			
 		}
+		Objects.requireNonNull(ds, "JAXB unmarshall returned null for URL "+configuration);
+		Objects.requireNonNull(ds.getMeta(), "/datasource/meta element missing");
 		ds.getMeta().setLastModified(conn.getLastModified());
 		ds.getMeta().setLocation(configuration);
 		return ds;

histream-import/src/main/java/de/sekmi/histream/etl/config/DecimalColumn.java

@@ -32,6 +32,8 @@ public class DecimalColumn extends Column<BigDecimal>{
 
 	@Override
 	public BigDecimal valueFromString(String input) throws ParseException {
+		// remove leading/trailing spaces
+		input = input.trim(); // TODO warning for user feedback if spaces were removed
 		if( locale == null ){
 			// parse according to BigDecimal(String)
 			try{
@@ -48,7 +50,7 @@ public class DecimalColumn extends Column<BigDecimal>{
 			try {
 				return (BigDecimal)decimalFormat.parse(input);
 			} catch (java.text.ParseException e) {
-				throw new ParseException("Unable to parse number '"+input+"'", e);
+				throw new ParseException("Unable to parse number '"+input+"' with locale "+locale, e);
 			}
 		}
 	}

histream-import/src/main/java/de/sekmi/histream/etl/config/IntegerColumn.java

@@ -20,6 +20,7 @@ public class IntegerColumn extends Column<Long> {
 
 	@Override
 	public Long valueFromString(String input) throws ParseException {
+		input = input.trim(); // TODO warning for user feedback if spaces were removed
 		return Long.parseLong(input);
 	}
 	

histream-skos/src/main/java/de/sekmi/histream/ontology/skos/Store.java

@@ -37,6 +37,7 @@ import de.sekmi.histream.ontology.OntologyException;
 import de.sekmi.histream.ontology.skos.transform.ConditionType;
 import de.sekmi.histream.ontology.skos.transform.Rule;
 import de.sekmi.histream.ontology.skos.transform.TransformationRules;
+import de.sekmi.histream.xml.NamespaceResolver;
 
 public class Store implements Ontology, Plugin {
 	private static final Logger log = Logger.getLogger(Store.class.getName());
@@ -47,7 +48,7 @@ public class Store implements Ontology, Plugin {
 	private Resource inferredContext;
 	// SKOS scheme to enforce unique notations
 	private Resource scheme;
-	
+	/// XXX  namespace resolver
 	/**
 	 * Plugin constructor which accepts configuration parameters.
 	 *