ZOOKEEPER-4965: Drop unnecessary deprecation warning suppressions

Reviewers: tisonkun
Author: kezhuw
Closes #2304 from kezhuw/ZOOKEEPER-4965-drop-unnecessary-deprecation-suppress

Author: kezhuw

zookeeper-server/src/main/java/org/apache/zookeeper/ZooKeeper.java

@@ -154,15 +154,14 @@ public class ZooKeeper implements AutoCloseable {
      *             instead.
      */
     @Deprecated
-    public static final String ZOOKEEPER_CLIENT_CNXN_SOCKET = "zookeeper.clientCnxnSocket";
-    // Setting this to "true" will enable encrypted client-server communication.
+    public static final String ZOOKEEPER_CLIENT_CNXN_SOCKET = ZKClientConfig.ZOOKEEPER_CLIENT_CNXN_SOCKET;
 
     /**
      * @deprecated Use {@link ZKClientConfig#SECURE_CLIENT}
      *             instead.
      */
     @Deprecated
-    public static final String SECURE_CLIENT = "zookeeper.client.secure";
+    public static final String SECURE_CLIENT = ZKClientConfig.SECURE_CLIENT;
 
     protected final ClientCnxn cnxn;
     private static final Logger LOG;

zookeeper-server/src/main/java/org/apache/zookeeper/client/ZKClientConfig.java

@@ -20,7 +20,6 @@
 
 import java.io.File;
 import org.apache.yetus.audience.InterfaceAudience;
-import org.apache.zookeeper.ZooKeeper;
 import org.apache.zookeeper.common.ZKConfig;
 import org.apache.zookeeper.server.quorum.QuorumPeerConfig.ConfigException;
 
@@ -35,13 +34,10 @@ public class ZKClientConfig extends ZKConfig {
     public static final String ZK_SASL_CLIENT_USERNAME_DEFAULT = "zookeeper";
     public static final String ZK_SASL_CLIENT_CANONICALIZE_HOSTNAME = "zookeeper.sasl.client.canonicalize.hostname";
     public static final String ZK_SASL_CLIENT_CANONICALIZE_HOSTNAME_DEFAULT = "true";
-    @SuppressWarnings("deprecation")
-    public static final String LOGIN_CONTEXT_NAME_KEY = ZooKeeperSaslClient.LOGIN_CONTEXT_NAME_KEY;
+    public static final String LOGIN_CONTEXT_NAME_KEY = "zookeeper.sasl.clientconfig";
     public static final String LOGIN_CONTEXT_NAME_KEY_DEFAULT = "Client";
-    @SuppressWarnings("deprecation")
-    public static final String ENABLE_CLIENT_SASL_KEY = ZooKeeperSaslClient.ENABLE_CLIENT_SASL_KEY;
-    @SuppressWarnings("deprecation")
-    public static final String ENABLE_CLIENT_SASL_DEFAULT = ZooKeeperSaslClient.ENABLE_CLIENT_SASL_DEFAULT;
+    public static final String ENABLE_CLIENT_SASL_KEY = "zookeeper.sasl.client";
+    public static final String ENABLE_CLIENT_SASL_DEFAULT = "true";
     public static final String ZOOKEEPER_SERVER_REALM = "zookeeper.server.realm";
     /**
      * This controls whether automatic watch resetting is enabled. Clients
@@ -50,13 +46,11 @@ public class ZKClientConfig extends ZKConfig {
      * "zookeeper.disableAutoWatchReset" to "true"
      */
     public static final String DISABLE_AUTO_WATCH_RESET = "zookeeper.disableAutoWatchReset";
-    @SuppressWarnings("deprecation")
-    public static final String ZOOKEEPER_CLIENT_CNXN_SOCKET = ZooKeeper.ZOOKEEPER_CLIENT_CNXN_SOCKET;
+    public static final String ZOOKEEPER_CLIENT_CNXN_SOCKET = "zookeeper.clientCnxnSocket";
     /**
      * Setting this to "true" will enable encrypted client-server communication.
      */
-    @SuppressWarnings("deprecation")
-    public static final String SECURE_CLIENT = ZooKeeper.SECURE_CLIENT;
+    public static final String SECURE_CLIENT = "zookeeper.client.secure";
     public static final int CLIENT_MAX_PACKET_LENGTH_DEFAULT = 0xfffff; /* 1 MB */
     public static final String ZOOKEEPER_REQUEST_TIMEOUT = "zookeeper.request.timeout";
     public static final String ZOOKEEPER_SERVER_PRINCIPAL = "zookeeper.server.principal";

zookeeper-server/src/main/java/org/apache/zookeeper/client/ZooKeeperSaslClient.java

@@ -54,19 +54,19 @@ public class ZooKeeperSaslClient {
      *             instead.
      */
     @Deprecated
-    public static final String LOGIN_CONTEXT_NAME_KEY = "zookeeper.sasl.clientconfig";
+    public static final String LOGIN_CONTEXT_NAME_KEY = ZKClientConfig.LOGIN_CONTEXT_NAME_KEY;
     /**
      * @deprecated Use {@link ZKClientConfig#ENABLE_CLIENT_SASL_KEY}
      *             instead.
      */
     @Deprecated
-    public static final String ENABLE_CLIENT_SASL_KEY = "zookeeper.sasl.client";
+    public static final String ENABLE_CLIENT_SASL_KEY = ZKClientConfig.ENABLE_CLIENT_SASL_KEY;
     /**
      * @deprecated Use {@link ZKClientConfig#ENABLE_CLIENT_SASL_DEFAULT}
      *             instead.
      */
     @Deprecated
-    public static final String ENABLE_CLIENT_SASL_DEFAULT = "true";
+    public static final String ENABLE_CLIENT_SASL_DEFAULT = ZKClientConfig.ENABLE_CLIENT_SASL_DEFAULT;
 
     /**
      * Returns true if the SASL client is enabled. By default, the client

zookeeper-server/src/main/java/org/apache/zookeeper/server/quorum/QuorumPeer.java

@@ -1439,7 +1439,6 @@ protected Election createElectionAlgorithm(int electionAlgorithm) {
         return le;
     }
 
-    @SuppressWarnings("deprecation")
     protected Election makeLEStrategy() {
         LOG.debug("Initializing leader election protocol...");
         return electionAlg;

zookeeper-server/src/test/java/org/apache/zookeeper/test/ReadOnlyModeTest.java

@@ -285,7 +285,6 @@ public void testGlobalSessionInRO() throws Exception {
      * Ensures that client seeks for r/w servers while it's connected to r/o
      * server.
      */
-    @SuppressWarnings("deprecation")
     @Test
     @Timeout(value = 90)
     public void testSeekForRwServer() throws Exception {