1 files changed, 41 insertions, 5 deletions
diff --git a/main/src/cgeo/geocaching/network/Parameters.java b/main/src/cgeo/geocaching/network/Parameters.java
index e65bec2..5c0328a 100644
--- a/main/src/cgeo/geocaching/network/Parameters.java
+++ b/main/src/cgeo/geocaching/network/Parameters.java
@@ -12,7 +12,7 @@ import java.util.Comparator;
 
 /**
  * List of key/values pairs to be used in a GET or POST request.
- * 
+ *
  */
 public class Parameters extends ArrayList<NameValuePair> {
 
@@ -44,14 +44,16 @@ public class Parameters extends ArrayList<NameValuePair> {
      *            list of key/value pairs
      * @throws InvalidParameterException
      *             if the number of key/values is unbalanced
+     * @return the object itself to facilitate chaining
      */
-    public void put(final String... keyValues) {
+    public Parameters put(final String... keyValues) {
         if (keyValues.length % 2 == 1) {
             throw new InvalidParameterException("odd number of parameters");
         }
         for (int i = 0; i < keyValues.length; i += 2) {
             add(new BasicNameValuePair(keyValues[i], keyValues[i + 1]));
         }
+        return this;
     }
 
     /**
@@ -63,12 +65,46 @@ public class Parameters extends ArrayList<NameValuePair> {
         Collections.sort(this, comparator);
     }
 
-    /**
-     * @return the URL encoded string corresponding to those parameters
-     */
     @Override
     public String toString() {
         return URLEncodedUtils.format(this, HTTP.UTF_8);
     }
 
+    /**
+     * Extend or create a Parameters object with new key/value pairs.
+     *
+     * @param params
+     *            an existing object or null to create a new one
+     * @param keyValues
+     *            list of key/value pair
+     * @throws InvalidParameterException
+     *             if the number of key/values is unbalanced
+     * @return the object itself if it is non-null, a new one otherwise
+     */
+    public static Parameters extend(final Parameters params, final String... keyValues) {
+        if (params == null) {
+            return new Parameters(keyValues);
+        } else {
+            return params.put(keyValues);
+        }
+    }
+
+    /**
+     * Merge two (possibly null) Parameters object.
+     *
+     * @param params
+     *            the object to merge into if non-null
+     * @param extra
+     *            the object to merge from if non-null
+     * @return params with extra data if params was non-null, extra otherwise
+     */
+    public static Parameters merge(final Parameters params, final Parameters extra) {
+        if (params == null) {
+            return extra;
+        } else if (extra != null) {
+            params.addAll(extra);
+        }
+        return params;
+    }
+
 }