add CsvReaderSettings

Preparation to add more complex CSV parsing rules.

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

@@ -0,0 +1,23 @@
+package org.lucares.pdbui;
+
+import org.lucares.utils.Preconditions;
+
+public class CsvReaderSettings {
+    private final byte separator;
+
+    public CsvReaderSettings(final byte separator) {
+        this.separator = separator;
+    }
+
+    public CsvReaderSettings(final char separator) {
+        Preconditions.checkTrue(separator == (byte) separator,
+                "Only separators that fulfill separator == (byte)separator are supported. "
+                        + "This restriction is because the parsing algorithm skips the overhead of "
+                        + "translating bytes to characters.");
+        this.separator = (byte) separator;
+    }
+
+    public byte getSeparator() {
+        return separator;
+    }
+}