add getDB() which return the db number we are connected to

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

@@ -30,6 +30,8 @@ public class BinaryClient extends Connection {
 
     private String password;
 
+    private long db;
+
     public boolean isInMulti() {
         return isInMulti;
     }
@@ -70,6 +72,7 @@ public class BinaryClient extends Connection {
     }
 
     public void quit() {
+        db = 0;
         sendCommand(QUIT);
     }
 
@@ -122,6 +125,7 @@ public class BinaryClient extends Connection {
     }
 
     public void select(final int index) {
+        db = index;
         sendCommand(SELECT, toByteArray(index));
     }
 
@@ -495,6 +499,7 @@ public class BinaryClient extends Connection {
             final double max) {
         sendCommand(ZRANGEBYSCORE, key, toByteArray(min), toByteArray(max));
     }
+
     public void zrevrangeByScore(final byte[] key, final double max,
             final double min) {
         sendCommand(ZREVRANGEBYSCORE, key, toByteArray(max), toByteArray(min));
@@ -504,6 +509,7 @@ public class BinaryClient extends Connection {
             final byte[] max) {
         sendCommand(ZRANGEBYSCORE, key, min, max);
     }
+
     public void zrevrangeByScore(final byte[] key, final byte[] max,
             final byte[] min) {
         sendCommand(ZREVRANGEBYSCORE, key, max, min);
@@ -514,6 +520,7 @@ public class BinaryClient extends Connection {
         sendCommand(ZRANGEBYSCORE, key, toByteArray(min), toByteArray(max),
                 LIMIT.raw, toByteArray(offset), toByteArray(count));
     }
+
     public void zrevrangeByScore(final byte[] key, final double max,
             final double min, final int offset, int count) {
         sendCommand(ZREVRANGEBYSCORE, key, toByteArray(max), toByteArray(min),
@@ -525,6 +532,7 @@ public class BinaryClient extends Connection {
         sendCommand(ZRANGEBYSCORE, key, toByteArray(min), toByteArray(max),
                 WITHSCORES.raw);
     }
+
     public void zrevrangeByScoreWithScores(final byte[] key, final double max,
             final double min) {
         sendCommand(ZREVRANGEBYSCORE, key, toByteArray(max), toByteArray(min),
@@ -537,6 +545,7 @@ public class BinaryClient extends Connection {
                 LIMIT.raw, toByteArray(offset), toByteArray(count),
                 WITHSCORES.raw);
     }
+
     public void zrevrangeByScoreWithScores(final byte[] key, final double max,
             final double min, final int offset, final int count) {
         sendCommand(ZREVRANGEBYSCORE, key, toByteArray(max), toByteArray(min),
@@ -692,6 +701,16 @@ public class BinaryClient extends Connection {
     }
 
     public void getrange(byte[] key, long startOffset, long endOffset) {
-        sendCommand(GETRANGE, key, toByteArray(startOffset), toByteArray(endOffset));
+        sendCommand(GETRANGE, key, toByteArray(startOffset),
+                toByteArray(endOffset));
+    }
+
+    public Long getDB() {
+        return db;
+    }
+
+    public void disconnect() {
+        db = 0;
+        super.disconnect();
     }
 }

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

@@ -2994,4 +2994,8 @@ public class BinaryJedis implements BinaryJedisCommands {
         jedisPubSub.proceedWithPatterns(client, patterns);
         client.rollbackTimeout();
     }
+
+    public Long getDB() {
+        return client.getDB();
+    }
 }

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

@@ -343,6 +343,13 @@ public class AllKindOfValuesCommandsTest extends JedisCommandTestBase {
         assertArrayEquals(bbar, jedis.get(bfoo));
     }
 
+    @Test
+    public void getDB() {
+        assertEquals(0, jedis.getDB().longValue());
+        jedis.select(1);
+        assertEquals(1, jedis.getDB().longValue());
+    }
+
     @Test
     public void move() {
         long status = jedis.move("foo", 1);