新增注释，方便理解

proxy-client/src/main/java/org/fengfei/lanproxy/client/ClientChannelMannager.java

@@ -28,12 +28,14 @@ import io.netty.util.AttributeKey;
  */
 public class ClientChannelMannager {
 
-    private static Logger logger = LoggerFactory.getLogger(ClientChannelMannager.class);
+    private static Logger LOGGER = LoggerFactory.getLogger(ClientChannelMannager.class);
 
     private static final AttributeKey<Boolean> USER_CHANNEL_WRITEABLE = AttributeKey.newInstance("user_channel_writeable");
 
     private static final AttributeKey<Boolean> CLIENT_CHANNEL_WRITEABLE = AttributeKey.newInstance("client_channel_writeable");
-
+    /**
+     * 最大连接数
+     */
     private static final int MAX_POOL_SIZE = 100;
 
     private static Map<String, Channel> realServerChannels = new ConcurrentHashMap<String, Channel>();
@@ -58,7 +60,7 @@ public class ClientChannelMannager {
                 if (future.isSuccess()) {
                     borrowListener.success(future.channel());
                 } else {
-                    logger.warn("connect proxy server failed", future.cause());
+                    LOGGER.warn("connect proxy server failed", future.cause());
                     borrowListener.error(future.cause());
                 }
             }
@@ -72,7 +74,7 @@ public class ClientChannelMannager {
             proxyChanel.config().setOption(ChannelOption.AUTO_READ, true);
             proxyChanel.attr(Constants.NEXT_CHANNEL).set(null);
             proxyChannelPool.offer(proxyChanel);
-            logger.debug("return ProxyChanel to the pool, channel is {}, pool size is {} ", proxyChanel, proxyChannelPool.size());
+            LOGGER.debug("return ProxyChanel to the pool, channel is {}, pool size is {} ", proxyChanel, proxyChannelPool.size());
         }
     }
 
@@ -113,7 +115,7 @@ public class ClientChannelMannager {
     }
 
     public static void clearRealServerChannels() {
-        logger.warn("channel closed, clear real server channels");
+        LOGGER.warn("channel closed, clear real server channels");
 
         Iterator<Entry<String, Channel>> ite = realServerChannels.entrySet().iterator();
         while (ite.hasNext()) {