PLUGIN-1936 : Improve exception handling for nextKeyValue() method

Author: sgarg-CS

src/e2e-test/java/io/cdap/plugin/servicenowsink/actions/ServiceNowSinkPropertiesPageActions.java

@@ -52,7 +52,7 @@ public class ServiceNowSinkPropertiesPageActions {
   private static Gson gson = new Gson();
 
   public static void getRecordFromServiceNowTable(String query, String tableName)
-      throws ServiceNowAPIException {
+      throws ServiceNowAPIException, IOException {
     config = new ServiceNowSourceConfig(
         "", "", "", "", "",
         System.getenv("SERVICE_NOW_CLIENT_ID"),

src/main/java/io/cdap/plugin/servicenow/source/ServiceNowBaseRecordReader.java

@@ -87,9 +87,14 @@ public boolean nextKeyValue() throws IOException {
       this.row = gson.fromJson(jsonReader, JsonObject.class); // assign row
       pos++;
       return true;
+    } else if (token == JsonToken.END_ARRAY) {
+      // This is the only "Normal" end of a page
+      closeCurrentPage();
+      return false;
+    } else {
+      // If we get here, the JSON is malformed or truncated
+      throw new IOException("Unexpected JSON token " + token + " at position " + pos);
     }
-    closeCurrentPage();
-    return false;
   }
 
   public boolean openNextPage() throws IOException, ServiceNowAPIException {
@@ -110,9 +115,8 @@ public boolean openNextPage() throws IOException, ServiceNowAPIException {
         top = jsonReader.peek();
         LOG.debug("Peeking JSON token for table {}: {}", tableName, top);
       } catch (IOException e) {
-        LOG.warn("Unexpected closure of stream while peeking JSON token for table {}", tableName, e);
         closeCurrentPage();
-        return false;
+        throw new IOException("Unexpected closure of stream while peeking JSON token for table {}" + tableName, e);
       }
       if (top == JsonToken.BEGIN_OBJECT) {
         jsonReader.beginObject();