sonar fixes

archiva-modules/archiva-base/archiva-checksum/src/main/java/org/apache/archiva/checksum/ChecksumAlgorithm.java

@@ -50,17 +50,17 @@ public enum ChecksumAlgorithm {
     /**
      * The MessageDigest algorithm for this hash.
      */
-    private String algorithm;
+    private final String algorithm;
 
     /**
      * The file extension for this ChecksumAlgorithm.
      */
-    private String ext;
+    private final String ext;
 
     /**
      * The checksum type, the key that you see in checksum files.
      */
-    private String type;
+    private final String type;
 
     /**
      * Construct a ChecksumAlgorithm

archiva-modules/archiva-base/archiva-checksum/src/main/java/org/apache/archiva/checksum/ChecksummedFile.java

@@ -25,7 +25,6 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.io.File;
-import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.file.Files;
@@ -52,7 +51,7 @@ import java.util.regex.Pattern;
  */
 public class ChecksummedFile
 {
-    private Logger log = LoggerFactory.getLogger( ChecksummedFile.class );
+    private final Logger log = LoggerFactory.getLogger( ChecksummedFile.class );
 
     private final File referenceFile;