sonarqube cleanup.

Author: karlnicholas

src/main/java/org/hdf5javalib/datatype/StringDatatype.java

@@ -248,6 +248,7 @@ public String toString() {
      */
     @Override
     public void writeDefinitionToByteBuffer(ByteBuffer buffer) {
+        // not implemented
     }
 
     /**

src/main/java/org/hdf5javalib/hdffile/dataobjects/messages/HdfMessage.java

@@ -105,7 +105,7 @@ protected void writeMessageData(ByteBuffer buffer) {
      */
     public abstract void writeMessageToByteBuffer(ByteBuffer buffer);
 
-    static class OBJECT_HEADER_PREFIX {
+    public static class OBJECT_HEADER_PREFIX {
         final MessageType type;
         final int size;
         final int flags;

src/main/java/org/hdf5javalib/hdfjava/HdfDataset.java

@@ -37,10 +37,11 @@ public boolean isDataset() {
 
     @Override
     public void close() throws Exception {
-
+        // not implemented
     }
 
     public void createAttribute(String attributeName, String attributeValue, HdfDataFile hdfDataFile) {
+        // not implemented
     }
 
     public Datatype getDatatype() {

src/main/java/org/hdf5javalib/utils/HdfDisplayUtils.java

@@ -29,6 +29,8 @@
 public class HdfDisplayUtils {
     private static final Logger log = LoggerFactory.getLogger(HdfDisplayUtils.class);
     public static final String UNDEFINED = "<Undefined>";
+    private static final String READ_EQUALS = " read = ";
+    private static final String STREAM_EQUALS = " stream = ";
 
     // Define a functional interface for actions that may need channel, dataset, and reader
     @FunctionalInterface
@@ -69,7 +71,7 @@ public static void displayFileAttr(Path filePath) {
     }
 
     public static void displayFile(Path filePath) {
-        processFile(filePath, (channel, dataSet, reader) -> displayData(channel, dataSet, reader));
+        processFile(filePath, HdfDisplayUtils::displayData);
     }
 
     public static void displayAttributes(HdfDataset dataSet) {
@@ -126,10 +128,10 @@ public static <T> void displayScalarData(SeekableByteChannel fileChannel, HdfDat
         TypedDataSource<T> dataSource = new TypedDataSource<>(fileChannel, hdfDataFile, dataSet, clazz);
 
         T result = dataSource.readScalar();
-        System.out.println(dataSet.getObjectName() + ":" + displayType(clazz, result) + " read   = " + displayValue(result));
+        System.out.println(dataSet.getObjectName() + ":" + displayType(clazz, result) + READ_EQUALS + displayValue(result));
 
         result = dataSource.streamScalar().findFirst().orElseThrow();
-        System.out.println(dataSet.getObjectName() + ":" + displayType(clazz, result) + " stream = " + displayValue(result));
+        System.out.println(dataSet.getObjectName() + ":" + displayType(clazz, result) + STREAM_EQUALS + displayValue(result));
     }
 
     /**
@@ -151,9 +153,9 @@ public static <T> void displayVectorData(SeekableByteChannel fileChannel, HdfDat
         TypedDataSource<T> dataSource = new TypedDataSource<>(fileChannel, hdfDataFile, dataSet, clazz);
 
         T[] resultArray = dataSource.readVector();
-        System.out.println(displayType(clazz, resultArray) + " read   = " + displayValue(resultArray));
+        System.out.println(displayType(clazz, resultArray) + READ_EQUALS + displayValue(resultArray));
 
-        System.out.print(displayType(clazz, resultArray) + " stream = [");
+        System.out.print(displayType(clazz, resultArray) + STREAM_EQUALS);
         String joined = dataSource.streamVector()
                 .map(HdfDisplayUtils::displayValue)
                 .collect(Collectors.joining(", "));
@@ -180,9 +182,9 @@ public static <T> void displayMatrixData(SeekableByteChannel fileChannel, HdfDat
         TypedDataSource<T> dataSource = new TypedDataSource<>(fileChannel, hdfDataFile, dataSet, clazz);
 
         T[][] resultArray = dataSource.readMatrix();
-        System.out.println(displayType(clazz, resultArray) + " read   = " + displayValue(resultArray));
+        System.out.println(displayType(clazz, resultArray) + READ_EQUALS + displayValue(resultArray));
 
-        System.out.print(displayType(clazz, resultArray) + " stream = [");
+        System.out.print(displayType(clazz, resultArray) + STREAM_EQUALS);
         String joined = dataSource.streamMatrix()
                 .map(HdfDisplayUtils::displayValue)
                 .collect(Collectors.joining(", "));