change length comparison to isEmpty method

JSONObject.java

@@ -810,11 +810,10 @@ public class JSONObject {
      * @return An array of field names, or null if there are no names.
      */
     public static String[] getNames(JSONObject jo) {
-        int length = jo.length();
-        if (length == 0) {
+        if (jo.isEmpty()) {
             return null;
         }
-        return jo.keySet().toArray(new String[length]);
+        return jo.keySet().toArray(new String[jo.length()]);
     }
 
     /**
@@ -972,15 +971,6 @@ public class JSONObject {
         return map.isEmpty();
     }
 
-    /**
-     * Check if JSONObject is not empty.
-     *
-     * @return true if JSONObject is not empty, otherwise false.
-     */
-    public boolean isNotEmpty() {
-        return !map.isEmpty();
-    }
-
     /**
      * Produce a JSONArray containing the names of the elements of this
      * JSONObject.
@@ -1966,7 +1956,7 @@ public class JSONObject {
     }
 
     public static Writer quote(String string, Writer w) throws IOException {
-        if (string == null || string.length() == 0) {
+        if (string == null || string.isEmpty()) {
             w.write("\"\"");
             return w;
         }
@@ -2245,7 +2235,7 @@ public class JSONObject {
      *             If any of the values are non-finite numbers.
      */
     public JSONArray toJSONArray(JSONArray names) throws JSONException {
-        if (names == null || names.length() == 0) {
+        if (names == null || names.isEmpty()) {
             return null;
         }
         JSONArray ja = new JSONArray();