Support CLUSTER SLOTS command

* CLUSTER SLOTS returns a Redis-formatted mapping from slot ranges to IP/Port pairs serving that slot range
* description link including output format
** e14829de30
* Unit test included

src/main/java/redis/clients/jedis/Client.java

@@ -1011,4 +1011,8 @@ public void clusterSetSlotStable(final int slot) {
     public void clusterFailover() {
 	cluster(Protocol.CLUSTER_FAILOVER);
     }
+    
+    public void clusterSlots() {
+	cluster(Protocol.CLUSTER_SLOTS);
+    }
 }

src/main/java/redis/clients/jedis/ClusterCommands.java

@@ -38,4 +38,6 @@ public interface ClusterCommands {
     List<String> clusterSlaves(final String nodeId);
     
     String clusterFailover();
+    
+    List<Object> clusterSlots();
 }

src/main/java/redis/clients/jedis/Jedis.java

@@ -3489,6 +3489,13 @@ public class Jedis extends BinaryJedis implements JedisCommands,
 	client.clusterFailover();
 	return client.getStatusCodeReply();
     }
+    
+    @Override
+    public List<Object> clusterSlots() {
+	checkIsInMulti();
+	client.clusterSlots();
+	return client.getObjectMultiBulkReply();
+    }
 
     public String asking() {
 	checkIsInMulti();

src/main/java/redis/clients/jedis/Protocol.java

@@ -59,6 +59,7 @@ public final class Protocol {
     public static final String CLUSTER_REPLICATE = "replicate";
     public static final String CLUSTER_SLAVES = "slaves";
     public static final String CLUSTER_FAILOVER = "failover";
+    public static final String CLUSTER_SLOTS = "slots";
     public static final String PUBSUB_CHANNELS= "channels";
     public static final String PUBSUB_NUMSUB = "numsub";
     public static final String PUBSUB_NUM_PAT = "numpat";

src/test/java/redis/clients/jedis/tests/commands/ClusterCommandsTest.java

@@ -45,6 +45,8 @@ public class ClusterCommandsTest extends JedisTestBase {
 	node1.clusterDelSlots(1, 2, 3, 4, 5, 500);
 	node1.clusterSetSlotNode(5000, node1Id);
 	node1.clusterDelSlots(5000, 10000);
+	node1.clusterDelSlots(3000, 3001, 3002);
+	node2.clusterDelSlots(4000, 4001, 4002);
 	node1.clusterAddSlots(6000);
 	node1.clusterDelSlots(6000);
 	waitForGossip();
@@ -134,5 +136,34 @@ public class ClusterCommandsTest extends JedisTestBase {
 	String status = node1.clusterSetSlotMigrating(5000, nodeId);
 	assertEquals("OK", status);
     }
+    
+    @Test
+    public void clusterSlots() {
+	// please see cluster slot output format from below commit
+	// @see:
+	// https://github.com/antirez/redis/commit/e14829de3025ffb0d3294e5e5a1553afd9f10b60
+	String status = node1.clusterAddSlots(3000, 3001, 3002);
+	assertEquals("OK", status);
+	status = node2.clusterAddSlots(4000, 4001, 4002);
+	assertEquals("OK", status);
+
+	List<Object> slots = node1.clusterSlots();
+	assertNotNull(slots);
+	assertTrue(slots.size() > 0);
+
+	for (Object slotInfoObj : slots) {
+	    List<Object> slotInfo = (List<Object>) slotInfoObj;
+	    assertNotNull(slots);
+	    assertTrue(slots.size() >= 2);
+
+	    assertTrue(slotInfo.get(0) instanceof Long);
+	    assertTrue(slotInfo.get(1) instanceof Long);
+
+	    if (slots.size() > 2) {
+		// assigned slots
+		assertTrue(slotInfo.get(2) instanceof List);
+	    }
+	}
+    }
 
 }