Moved the sort order to the SQL fixing a paging bug.

The sort order was currently only be applied to the page. This has since been fixed and is now applied to the SQL therefore the entire result set, not just the current page, will be affected by the sort order.

src/org/ohmage/domain/campaign/SurveyResponse.java

@@ -687,7 +687,7 @@ public static enum SortParameter {
 		USER ("username");
 
 		// The string used to represent the columns on which to order.
-		private String sqlColumn;
+		private final String sqlColumn;
 
 		/**
 		 * Creates a sort parameter with a String representing the SQL 

src/org/ohmage/query/impl/SurveyResponseQueries.java

@@ -1012,25 +1012,30 @@ else if(onSurveyResponse || forCount) {
 
 		// Finally, add some ordering to facilitate consistent results in the
 		// paging system.
-		sqlBuilder.append(" ORDER BY ");
-		boolean firstPass = true;
-		for(SortParameter sortParameter : sortOrder) {
+		if(sortOrder == null) {
+			sqlBuilder.append(" ORDER BY epoch_millis DESC, uuid");
+		}
+		else {
+			sqlBuilder.append(" ORDER BY ");
+			boolean firstPass = true;
+			for(SortParameter sortParameter : sortOrder) {
+				if(firstPass) {
+					firstPass = false;
+				}
+				else {
+					sqlBuilder.append(", ");
+				}
+
+				sqlBuilder.append(sortParameter.getSqlColumn());
+			}
+			// We must always include the UUID in the order to guarantee that 
+			// all survey responses are grouped together.
 			if(firstPass) {
-				firstPass = false;
+				sqlBuilder.append("uuid");
 			}
 			else {
-				sqlBuilder.append(", ");
+				sqlBuilder.append(", uuid");
 			}
-
-			sqlBuilder.append(sortParameter.getSqlColumn());
-		}
-		// We must always include the UUID in the order to guarantee that all
-		// survey responses are grouped together.
-		if(firstPass) {
-			sqlBuilder.append("uuid");
-		}
-		else {
-			sqlBuilder.append(", uuid");
 		}
 
 		return sqlBuilder.toString();

src/org/ohmage/request/survey/SurveyResponseReadRequest.java

@@ -248,14 +248,9 @@ public final class SurveyResponseReadRequest extends UserRequest {
 
 	public static final String URN_SPECIAL_ALL = "urn:ohmage:special:all";
 	public static final Collection<String> URN_SPECIAL_ALL_LIST;
-	public static final List<SortParameter> DEFAULT_SORT_ORDER;
 	static {
 		URN_SPECIAL_ALL_LIST = new HashSet<String>();
 		URN_SPECIAL_ALL_LIST.add(URN_SPECIAL_ALL);
-
-		List<SortParameter> tmpSortOrder = new ArrayList<SortParameter>();
-		tmpSortOrder.add(SortParameter.TIMESTAMP);
-		DEFAULT_SORT_ORDER = Collections.unmodifiableList(tmpSortOrder);
 	}
 
 	private static final int MAX_NUMBER_OF_USERS = 10;
@@ -309,7 +304,7 @@ public SurveyResponseReadRequest(HttpServletRequest httpRequest) {
 		Date tStartDate = null;
 		Date tEndDate = null;
 
-		List<SortParameter> tSortOrder = DEFAULT_SORT_ORDER;
+		List<SortParameter> tSortOrder = null;
 
 		SurveyResponse.PrivacyState tPrivacyState = null;
 

src/org/ohmage/validator/SurveyResponseValidators.java

@@ -338,7 +338,7 @@ public static List<SortParameter> validateSortOrder(
 			throws ValidationException {
 
 		if(StringUtils.isEmptyOrWhitespaceOnly(sortOrder)) {
-			return SurveyResponseReadRequest.DEFAULT_SORT_ORDER;
+			return null;
 		}
 
 		List<SortParameter> result = new ArrayList<SortParameter>(3);

test/org/ohmage/validator/SurveyResponseValidatorsTest.java

@@ -331,7 +331,7 @@ public void testValidateOutputFormat() {
 	public void testValidateSortOrder() {
 		try {
 			for(String emptyValue : ParameterSets.getEmptyValues()) {
-				Assert.assertEquals(SurveyResponseValidators.validateSortOrder(emptyValue), SurveyResponseReadRequest.DEFAULT_SORT_ORDER);
+				Assert.assertNull(SurveyResponseValidators.validateSortOrder(emptyValue));
 			}
 
 			try {