Retry at okhttp native Socket closed exception (#364)

Author: miniway

src/main/java/com/treasuredata/client/TDRequestErrorHandler.java

@@ -24,6 +24,7 @@
 import java.text.SimpleDateFormat;
 import java.util.Date;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Optional;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
@@ -181,6 +182,10 @@ else if (e instanceof SocketException) {
                 // All known SocketException are retryable.
                 return new TDClientSocketException(socketException);
             }
+            else if (Objects.equals(socketException.getMessage(), "Socket closed")) {
+                // okhttp can raise java.net.SocketException("Socket closed")
+                return new TDClientSocketException(socketException);
+            }
             else {
                 // Other unknown SocketException are considered non-retryable.
                 throw new TDClientSocketException(socketException);