renamenx and renamenxAsync methods added. #141

src/main/java/org/redisson/RedissonObject.java

@@ -20,6 +20,7 @@ import io.netty.util.concurrent.Promise;
 
 import org.redisson.async.AsyncOperation;
 import org.redisson.async.OperationListener;
+import org.redisson.async.ResultOperation;
 import org.redisson.connection.ConnectionManager;
 import org.redisson.core.RObject;
 
@@ -66,6 +67,20 @@ abstract class RedissonObject implements RObject {
             }
         });
     }
+    
+    public boolean renamenx(String newName) {
+        return connectionManager.get(renamenxAsync(newName));
+    }
+    
+    public Future<Boolean> renamenxAsync(final String newName) {
+        return connectionManager.writeAsync(getName(), new ResultOperation<Boolean, Object>() {
+            @Override
+            public Future<Boolean> execute(RedisAsyncConnection<Object, Object> async) {
+                return async.renamenx(getName(), newName);
+            }
+        });
+    }
+
 
     public boolean delete() {
         return connectionManager.get(deleteAsync());

src/main/java/org/redisson/core/RObject.java

@@ -39,8 +39,39 @@ public interface RObject {
     
     Future<Boolean> deleteAsync();
 
+    /**
+     * Rename current object key to <code>newName</code>
+     * 
+     * @param newName
+     * @return
+     */
     boolean rename(String newName);
-    
+
+    /**
+     * Rename current object key to <code>newName</code>
+     * in async mode
+     * 
+     * @param newName
+     * @return
+     */
     Future<Boolean> renameAsync(String newName);
+
+    /**
+     * Rename current object key to <code>newName</code>
+     * only if new key is not exists 
+     * 
+     * @param newName
+     * @return
+     */
+    boolean renamenx(String newName);
+
+    /**
+     * Rename current object key to <code>newName</code>
+     * in async mode only if new key is not exists
+     * 
+     * @param newName
+     * @return
+     */
+    Future<Boolean> renamenxAsync(String newName);
     
 }

src/test/java/org/redisson/RedissonBucketTest.java

@@ -10,6 +10,20 @@ import java.util.List;
 
 public class RedissonBucketTest extends BaseTest {
 
+    @Test
+    public void testRenamenx() {
+        RBucket<String> bucket = redisson.getBucket("test");
+        bucket.set("someValue");
+        RBucket<String> bucket2 = redisson.getBucket("test2");
+        bucket2.set("someValue2");
+        Assert.assertTrue(bucket.renamenx("test1"));
+        RBucket<String> oldBucket = redisson.getBucket("test");
+        Assert.assertNull(oldBucket.get());
+        RBucket<String> newBucket = redisson.getBucket("test1");
+        Assert.assertEquals("someValue", newBucket.get());
+        Assert.assertFalse(newBucket.renamenx("test2"));
+    }
+    
     @Test
     public void testRename() {
         RBucket<String> bucket = redisson.getBucket("test");