Add a interface "FSTDataProvider" which helps you getting data for a given FSTEntry

src/de/mas/wiiu/jnus/interfaces/FSTDataProvider.java

@@ -0,0 +1,22 @@
+package de.mas.wiiu.jnus.interfaces;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Optional;
+
+import de.mas.wiiu.jnus.entities.fst.FSTEntry;
+
+public interface FSTDataProvider {
+    public String getName();
+
+    public FSTEntry getRoot();
+
+    public default byte[] readFile(FSTEntry entry) throws IOException {
+        return readFile(entry, 0, entry.getFileSize());
+    }
+
+    public byte[] readFile(FSTEntry entry, long offset, long size) throws IOException;
+
+    public InputStream readFileAsStream(FSTEntry entry, long offset, Optional<Long> size) throws IOException;
+
+}