--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/app/src/main/java/org/tn5250j/encoding/builtin/CodepageConverterAdapter.java	Thu Dec 03 11:23:55 2015 -0800
@@ -0,0 +1,85 @@
+/**
+ * $Id$
+ *
+ * Title: tn5250J
+ * Copyright:   Copyright (c) 2001,2009
+ * Company:
+ * @author: master_jaf
+ *
+ * Description:
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this software; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
+ * Boston, MA 02111-1307 USA
+ *
+ */
+package org.tn5250j.encoding.builtin;
+
+import java.util.Arrays;
+
+/**
+ * Adapter class for converters using 8bit codepages.
+ *
+ * @author master_jaf
+ */
+public abstract class CodepageConverterAdapter implements ICodepageConverter {
+
+    private char[] codepage = null;
+    private int[] reverse_codepage = null;
+
+    /* (non-Javadoc)
+     * @see org.tn5250j.cp.ICodepageConverter#init()
+     */
+    public ICodepageConverter init() {
+        codepage = getCodePage();
+        int size = 0;
+
+        for (int i = 0; i < codepage.length; i++) {
+            size = Math.max(size, codepage[i]);
+        }
+
+        assert(size + 1) < 1024 * 1024; // some kind of maximum size limiter.
+        reverse_codepage = new int[size + 1];
+        Arrays.fill(reverse_codepage, '?');
+
+        for (int i = 0; i < codepage.length; i++) {
+            reverse_codepage[codepage[i]] = i;
+        }
+
+        return this;
+    }
+
+    /* (non-Javadoc)
+     * @see org.tn5250j.cp.ICodepageConverter#uni2ebcdic(char)
+     */
+    public byte uni2ebcdic(char index) {
+        assert index < reverse_codepage.length;
+        return (byte)reverse_codepage[index];
+    }
+
+    /* (non-Javadoc)
+     * @see org.tn5250j.cp.ICodepageConverter#ebcdic2uni(int)
+     */
+    public char ebcdic2uni(int index) {
+        index = index & 0xFF;
+        assert index < 256;
+        return codepage[index];
+    }
+
+    /**
+     * @return The oringal 8bit codepage.
+     */
+    protected abstract char[] getCodePage();
+
+}