ignore comment lines in CSV files

pdb-ui/src/main/java/org/lucares/pdbui/CsvReaderSettings.java

@@ -1,6 +1,7 @@
 package org.lucares.pdbui;
 
 import java.util.Collection;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
@@ -18,9 +19,10 @@ public class CsvReaderSettings {
 
     private String timeColumn;
 
+    private byte comment = '#';
+
     public CsvReaderSettings() {
-        separator = ',';
-        timeColumn = "@timestamp";
+        this("@timestamp", (byte) ',', Collections.emptyList());
     }
 
     private CsvReaderSettings(final String timeColumn, final byte separator, final Collection<String> ignoreColumns) {
@@ -65,6 +67,14 @@ public class CsvReaderSettings {
         this.separator = separator;
     }
 
+    public byte getComment() {
+        return comment;
+    }
+
+    public void setComment(final byte comment) {
+        this.comment = comment;
+    }
+
     public Set<String> getIgnoreColumnNames() {
         return ignoreColumnNames;
     }

pdb-ui/src/main/java/org/lucares/pdbui/CsvToEntryTransformer.java

@@ -38,6 +38,7 @@ class CsvToEntryTransformer {
 
         final byte newline = '\n';
         final byte separator = settings.getSeparator();
+        final byte comment = settings.getComment();
         final byte[] line = new byte[64 * 1024]; // max line length
         int offsetInLine = 0;
         int offsetInBuffer = 0;
@@ -64,7 +65,9 @@ class CsvToEntryTransformer {
                     bytesInLine = offsetInLine + length;
                     separatorPositions.add(offsetInLine + i - offsetInBuffer);
 
-                    if (columns != null) {
+                    if (line[0] == comment) {
+                        // ignore
+                    } else if (columns != null) {
 
                         final Entry entry = handleCsvLine(columns, line, bytesInLine, separatorPositions, keyTimestamp,
                                 keyDuration, dateParser, additionalTags);