RBucket.trySet & RBucket.trySetAsync methods added

src/main/java/org/redisson/RedissonBucket.java

@@ -84,4 +84,14 @@ public class RedissonBucket<V> extends RedissonExpirable implements RBucket<V> {
         return isExists();
     }
 
+    @Override
+    public Future<Boolean> trySetAsync(V value) {
+        return commandExecutor.writeAsync(getName(), codec, RedisCommands.SETNX, getName(), value);
+    }
+
+    @Override
+    public boolean trySet(V value) {
+        return get(trySetAsync(value));
+    }
+
 }

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

@@ -28,6 +28,8 @@ public interface RBucket<V> extends RExpirable, RBucketAsync<V> {
 
     V get();
 
+    boolean trySet(V value);
+
     void set(V value);
 
     void set(V value, long timeToLive, TimeUnit timeUnit);

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

@@ -30,6 +30,8 @@ public interface RBucketAsync<V> extends RExpirableAsync {
 
     Future<V> getAsync();
 
+    Future<Boolean> trySetAsync(V value);
+
     Future<Void> setAsync(V value);
 
     Future<Void> setAsync(V value, long timeToLive, TimeUnit timeUnit);

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

@@ -14,6 +14,14 @@ import static org.assertj.core.api.Assertions.*;
 
 public class RedissonBucketTest extends BaseTest {
 
+    @Test
+    public void testTrySet() {
+        RBucket<String> r1 = redisson.getBucket("12");
+        assertThat(r1.trySet("3")).isTrue();
+        assertThat(r1.trySet("4")).isFalse();
+        assertThat(r1.get()).isEqualTo("3");
+    }
+
     @Test
     public void testSaveBuckets() {
         Map<String, Integer> buckets = new HashMap<String, Integer>();