Prevent use of reflection in tests

Author: tomdesair

.travis.yml

@@ -6,7 +6,8 @@ jdk:
 - oraclejdk9
 - openjdk8
 # https://docs.travis-ci.com/user/reference/trusty/#jvm-clojure-groovy-java-scala-images
-# Oracle JDK 10 is not provided because it reached End of Life in October 2018.
+# - Oracle JDK 10 is not provided because it reached End of Life in October 2018.
+# - JDK 7 is not listed as the Sonar plugin requires Java 8. However, all JDKs compile with target version 7.
 
 addons:
   sonarcloud:

src/test/java/me/desair/tus/server/upload/disk/FileBasedLockTest.java

@@ -5,7 +5,7 @@
 import static org.mockito.Mockito.anyBoolean;
 import static org.mockito.Mockito.anyLong;
 import static org.mockito.Mockito.doReturn;
-import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.spy;
 
 import java.io.IOException;
 import java.nio.channels.FileChannel;
@@ -17,13 +17,9 @@
 import me.desair.tus.server.exception.UploadAlreadyLockedException;
 import org.junit.BeforeClass;
 import org.junit.Test;
-import org.springframework.test.util.ReflectionTestUtils;
-
 
 public class FileBasedLockTest {
 
-    private DiskStorageService storageService;
-
     private static Path storagePath;
 
     @BeforeClass
@@ -92,10 +88,6 @@ public void testLockIOException() throws UploadAlreadyLockedException, IOExcepti
     }
 
     private FileChannel createFileChannelMock() throws IOException {
-        FileChannel channel = mock(FileChannel.class);
-
-        ReflectionTestUtils.setField(channel, "closeLock", new Object());
-        ReflectionTestUtils.setField(channel, "open", true);
-        return channel;
+        return spy(FileChannel.class);
     }
 }