Change to EditN3Generator that will effect how all null and empty values get substituted into N3 on front end edits. NIHVIVO-3400

webapp/src/edu/cornell/mannlib/vitro/webapp/edit/n3editing/VTwo/EditN3GeneratorVTwo.java

@@ -52,10 +52,22 @@ public class EditN3GeneratorVTwo {
     	        continue;
             Set<String> keySet = varsToVals.keySet();
             for (String key : keySet) {
-                List<String> value = varsToVals.get(key);                
+                List<String> values = varsToVals.get(key);  
-                log.debug("The original value String is " + value.toString());
+                if( values == null ){
+                    log.debug("skipping var " + key + " because value List is null");
+                    continue;
+                }else if( containsNullOrEmpty( values )){
+                    
+                    //bdc34: what should we do if the list contains nulls or empty strings?
+                    //for now we just skip the whole key/var.  
+                    //Maybe it would be useful to strip the nulls+empties out of the list?
+                    
+                    log.debug("skipping var " + key + " because it contains nulls or empty strings");
+                    continue;
+                }
+                log.debug("The original value String is " + values.toString());                
                 
-                String valueString = org.apache.commons.lang.StringUtils.join(value,
+                String valueString = org.apache.commons.lang.StringUtils.join(values,
                         ">, <");                                
                 valueString = "<" + valueString + ">";                
                 log.debug("The multiUri value String is " + valueString);
@@ -66,6 +78,10 @@ public class EditN3GeneratorVTwo {
         }         
     }
   
+    private boolean containsNullOrEmpty(List<String> values) {        
+        return values != null && ( values.contains(null) || values.contains("") );       
+    }
+
     /**
      * The List targets will be modified.
      */

webapp/test/edu/cornell/mannlib/vitro/webapp/edit/n3editing/VTwo/EditN3GeneratorVTwoTest.java

@@ -154,8 +154,34 @@ public class EditN3GeneratorVTwoTest {
         
         String not_expected = "<null>";
         Assert.assertTrue("must not sub in <null>", !not_expected.equals(resultN3));
+                        
+        not_expected = "<>";        
+        Assert.assertTrue("must not sub in <>", !not_expected.equals(resultN3));
+        
+        Assert.assertEquals("?varXYZ", resultN3);
     }
     
+    @Test 
+    public void testSubInMultiUrisEmptyString(){        
+        String n3 = "?varXYZ" ;
+        List<String> targets = new ArrayList<String>();
+        targets.add(n3);
+        
+        Map<String,List<String>> keyToValues = new HashMap<String,List<String>>();
+        List<String> targetValue = new ArrayList<String>();        
+        targetValue.add("");       
+        keyToValues.put("varXYZ", targetValue);
+        
+        gen.subInMultiUris(keyToValues, targets);
+        Assert.assertNotNull(targets);
+        Assert.assertEquals(1,targets.size());
+        
+        String resultN3 = targets.get(0);
+        Assert.assertNotNull(resultN3);
+        Assert.assertTrue("String was empty", !resultN3.isEmpty());                
+                                
+        Assert.assertEquals("?varXYZ", resultN3);
+    }
     
     @Test 
     public void testSubInUrisNull(){