[SPARK-17332][CORE] Make Java Loggers static members

## What changes were proposed in this pull request?

Make all Java Loggers static members

## How was this patch tested?

Jenkins

Author: Sean Owen <sowen@cloudera.com>

Closes #14896 from srowen/SPARK-17332.

14 files changed, 15 insertions, 14 deletions

diff --git a/common/network-common/src/main/java/org/apache/spark/network/TransportContext.java b/common/network-common/src/main/java/org/apache/spark/network/TransportContext.java
index 5320b28bc0..5b69e2bb03 100644
--- a/common/network-common/src/main/java/org/apache/spark/network/TransportContext.java
+++ b/common/network-common/src/main/java/org/apache/spark/network/TransportContext.java
@@ -56,7 +56,7 @@ import org.apache.spark.network.util.TransportFrameDecoder;
  * processes to send messages back to the client on an existing channel.
  */
 public class TransportContext {
-  private final Logger logger = LoggerFactory.getLogger(TransportContext.class);
+  private static final Logger logger = LoggerFactory.getLogger(TransportContext.class);
 
   private final TransportConf conf;
   private final RpcHandler rpcHandler;
diff --git a/common/network-common/src/main/java/org/apache/spark/network/client/TransportClient.java b/common/network-common/src/main/java/org/apache/spark/network/client/TransportClient.java
index a67683b892..600b80e2c5 100644
--- a/common/network-common/src/main/java/org/apache/spark/network/client/TransportClient.java
+++ b/common/network-common/src/main/java/org/apache/spark/network/client/TransportClient.java
@@ -72,7 +72,7 @@ import static org.apache.spark.network.util.NettyUtils.getRemoteAddress;
  * Concurrency: thread safe and can be called from multiple threads.
  */
 public class TransportClient implements Closeable {
-  private final Logger logger = LoggerFactory.getLogger(TransportClient.class);
+  private static final Logger logger = LoggerFactory.getLogger(TransportClient.class);
 
   private final Channel channel;
   private final TransportResponseHandler handler;
diff --git a/common/network-common/src/main/java/org/apache/spark/network/client/TransportClientFactory.java b/common/network-common/src/main/java/org/apache/spark/network/client/TransportClientFactory.java
index 1c9916baee..e895f13f45 100644
--- a/common/network-common/src/main/java/org/apache/spark/network/client/TransportClientFactory.java
+++ b/common/network-common/src/main/java/org/apache/spark/network/client/TransportClientFactory.java
@@ -73,7 +73,7 @@ public class TransportClientFactory implements Closeable {
     }
   }
 
-  private final Logger logger = LoggerFactory.getLogger(TransportClientFactory.class);
+  private static final Logger logger = LoggerFactory.getLogger(TransportClientFactory.class);
 
   private final TransportContext context;
   private final TransportConf conf;
diff --git a/common/network-common/src/main/java/org/apache/spark/network/client/TransportResponseHandler.java b/common/network-common/src/main/java/org/apache/spark/network/client/TransportResponseHandler.java
index 179667296e..41bead546c 100644
--- a/common/network-common/src/main/java/org/apache/spark/network/client/TransportResponseHandler.java
+++ b/common/network-common/src/main/java/org/apache/spark/network/client/TransportResponseHandler.java
@@ -48,7 +48,7 @@ import org.apache.spark.network.util.TransportFrameDecoder;
  * Concurrency: thread safe and can be called from multiple threads.
  */
 public class TransportResponseHandler extends MessageHandler<ResponseMessage> {
-  private final Logger logger = LoggerFactory.getLogger(TransportResponseHandler.class);
+  private static final Logger logger = LoggerFactory.getLogger(TransportResponseHandler.class);
 
   private final Channel channel;
 
diff --git a/common/network-common/src/main/java/org/apache/spark/network/protocol/MessageDecoder.java b/common/network-common/src/main/java/org/apache/spark/network/protocol/MessageDecoder.java
index f045318618..f0956438ad 100644
--- a/common/network-common/src/main/java/org/apache/spark/network/protocol/MessageDecoder.java
+++ b/common/network-common/src/main/java/org/apache/spark/network/protocol/MessageDecoder.java
@@ -33,7 +33,8 @@ import org.slf4j.LoggerFactory;
 @ChannelHandler.Sharable
 public final class MessageDecoder extends MessageToMessageDecoder<ByteBuf> {
 
-  private final Logger logger = LoggerFactory.getLogger(MessageDecoder.class);
+  private static final Logger logger = LoggerFactory.getLogger(MessageDecoder.class);
+
   @Override
   public void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) {
     Message.Type msgType = Message.Type.decode(in);
diff --git a/common/network-common/src/main/java/org/apache/spark/network/protocol/MessageEncoder.java b/common/network-common/src/main/java/org/apache/spark/network/protocol/MessageEncoder.java
index 664df57fec..276f16637e 100644
--- a/common/network-common/src/main/java/org/apache/spark/network/protocol/MessageEncoder.java
+++ b/common/network-common/src/main/java/org/apache/spark/network/protocol/MessageEncoder.java
@@ -33,7 +33,7 @@ import org.slf4j.LoggerFactory;
 @ChannelHandler.Sharable
 public final class MessageEncoder extends MessageToMessageEncoder<Message> {
 
-  private final Logger logger = LoggerFactory.getLogger(MessageEncoder.class);
+  private static final Logger logger = LoggerFactory.getLogger(MessageEncoder.class);
 
   /***
    * Encodes a Message by invoking its encode() method. For non-data messages, we will add one
diff --git a/common/network-common/src/main/java/org/apache/spark/network/sasl/SaslClientBootstrap.java b/common/network-common/src/main/java/org/apache/spark/network/sasl/SaslClientBootstrap.java
index 68381037d6..9e5c616ee5 100644
--- a/common/network-common/src/main/java/org/apache/spark/network/sasl/SaslClientBootstrap.java
+++ b/common/network-common/src/main/java/org/apache/spark/network/sasl/SaslClientBootstrap.java
@@ -38,7 +38,7 @@ import org.apache.spark.network.util.TransportConf;
  * server should be setup with a {@link SaslRpcHandler} with matching keys for the given appId.
  */
 public class SaslClientBootstrap implements TransportClientBootstrap {
-  private final Logger logger = LoggerFactory.getLogger(SaslClientBootstrap.class);
+  private static final Logger logger = LoggerFactory.getLogger(SaslClientBootstrap.class);
 
   private final boolean encrypt;
   private final TransportConf conf;
diff --git a/common/network-common/src/main/java/org/apache/spark/network/sasl/SparkSaslClient.java b/common/network-common/src/main/java/org/apache/spark/network/sasl/SparkSaslClient.java
index 94685e91b8..b6256debb8 100644
--- a/common/network-common/src/main/java/org/apache/spark/network/sasl/SparkSaslClient.java
+++ b/common/network-common/src/main/java/org/apache/spark/network/sasl/SparkSaslClient.java
@@ -43,7 +43,7 @@ import static org.apache.spark.network.sasl.SparkSaslServer.*;
  * firstToken, which is then followed by a set of challenges and responses.
  */
 public class SparkSaslClient implements SaslEncryptionBackend {
-  private final Logger logger = LoggerFactory.getLogger(SparkSaslClient.class);
+  private static final Logger logger = LoggerFactory.getLogger(SparkSaslClient.class);
 
   private final String secretKeyId;
   private final SecretKeyHolder secretKeyHolder;
diff --git a/common/network-common/src/main/java/org/apache/spark/network/sasl/SparkSaslServer.java b/common/network-common/src/main/java/org/apache/spark/network/sasl/SparkSaslServer.java
index b802a5af63..e24fdf0c74 100644
--- a/common/network-common/src/main/java/org/apache/spark/network/sasl/SparkSaslServer.java
+++ b/common/network-common/src/main/java/org/apache/spark/network/sasl/SparkSaslServer.java
@@ -45,7 +45,7 @@ import org.slf4j.LoggerFactory;
  * connections on some socket.)
  */
 public class SparkSaslServer implements SaslEncryptionBackend {
-  private final Logger logger = LoggerFactory.getLogger(SparkSaslServer.class);
+  private static final Logger logger = LoggerFactory.getLogger(SparkSaslServer.class);
 
   /**
    * This is passed as the server name when creating the sasl client/server.
diff --git a/common/network-common/src/main/java/org/apache/spark/network/server/OneForOneStreamManager.java b/common/network-common/src/main/java/org/apache/spark/network/server/OneForOneStreamManager.java
index ae7e520b2f..ee367f9998 100644
--- a/common/network-common/src/main/java/org/apache/spark/network/server/OneForOneStreamManager.java
+++ b/common/network-common/src/main/java/org/apache/spark/network/server/OneForOneStreamManager.java
@@ -36,7 +36,7 @@ import org.apache.spark.network.client.TransportClient;
  * individually fetched as chunks by the client. Each registered buffer is one chunk.
  */
 public class OneForOneStreamManager extends StreamManager {
-  private final Logger logger = LoggerFactory.getLogger(OneForOneStreamManager.class);
+  private static final Logger logger = LoggerFactory.getLogger(OneForOneStreamManager.class);
 
   private final AtomicLong nextStreamId;
   private final ConcurrentHashMap<Long, StreamState> streams;
diff --git a/common/network-common/src/main/java/org/apache/spark/network/server/RpcHandler.java b/common/network-common/src/main/java/org/apache/spark/network/server/RpcHandler.java
index a99c3015b0..8f7554e2e0 100644
--- a/common/network-common/src/main/java/org/apache/spark/network/server/RpcHandler.java
+++ b/common/network-common/src/main/java/org/apache/spark/network/server/RpcHandler.java
@@ -83,7 +83,7 @@ public abstract class RpcHandler {
 
   private static class OneWayRpcCallback implements RpcResponseCallback {
 
-    private final Logger logger = LoggerFactory.getLogger(OneWayRpcCallback.class);
+    private static final Logger logger = LoggerFactory.getLogger(OneWayRpcCallback.class);
 
     @Override
     public void onSuccess(ByteBuffer response) {
diff --git a/common/network-common/src/main/java/org/apache/spark/network/server/TransportChannelHandler.java b/common/network-common/src/main/java/org/apache/spark/network/server/TransportChannelHandler.java
index 884ea7d115..c33848c840 100644
--- a/common/network-common/src/main/java/org/apache/spark/network/server/TransportChannelHandler.java
+++ b/common/network-common/src/main/java/org/apache/spark/network/server/TransportChannelHandler.java
@@ -49,7 +49,7 @@ import static org.apache.spark.network.util.NettyUtils.getRemoteAddress;
  * timeout if the client is continuously sending but getting no responses, for simplicity.
  */
 public class TransportChannelHandler extends SimpleChannelInboundHandler<Message> {
-  private final Logger logger = LoggerFactory.getLogger(TransportChannelHandler.class);
+  private static final Logger logger = LoggerFactory.getLogger(TransportChannelHandler.class);
 
   private final TransportClient client;
   private final TransportResponseHandler responseHandler;
diff --git a/common/network-common/src/main/java/org/apache/spark/network/server/TransportRequestHandler.java b/common/network-common/src/main/java/org/apache/spark/network/server/TransportRequestHandler.java
index e67a034cb8..0373ed950e 100644
--- a/common/network-common/src/main/java/org/apache/spark/network/server/TransportRequestHandler.java
+++ b/common/network-common/src/main/java/org/apache/spark/network/server/TransportRequestHandler.java
@@ -53,7 +53,7 @@ import static org.apache.spark.network.util.NettyUtils.getRemoteAddress;
  * The messages should have been processed by the pipeline setup by {@link TransportServer}.
  */
 public class TransportRequestHandler extends MessageHandler<RequestMessage> {
-  private final Logger logger = LoggerFactory.getLogger(TransportRequestHandler.class);
+  private static final Logger logger = LoggerFactory.getLogger(TransportRequestHandler.class);
 
   /** The Netty channel that this handler is associated with. */
   private final Channel channel;
diff --git a/common/network-common/src/main/java/org/apache/spark/network/server/TransportServer.java b/common/network-common/src/main/java/org/apache/spark/network/server/TransportServer.java
index a67db4f69f..0d7a677820 100644
--- a/common/network-common/src/main/java/org/apache/spark/network/server/TransportServer.java
+++ b/common/network-common/src/main/java/org/apache/spark/network/server/TransportServer.java
@@ -44,7 +44,7 @@ import org.apache.spark.network.util.TransportConf;
  * Server for the efficient, low-level streaming service.
  */
 public class TransportServer implements Closeable {
-  private final Logger logger = LoggerFactory.getLogger(TransportServer.class);
+  private static final Logger logger = LoggerFactory.getLogger(TransportServer.class);
 
   private final TransportContext context;
   private final TransportConf conf;