Its possible to load and save a truth table.

src/main/java/de/neemann/digital/analyse/TruthTable.java

@@ -1,5 +1,8 @@
 package de.neemann.digital.analyse;
 
+import com.thoughtworks.xstream.XStream;
+import com.thoughtworks.xstream.io.xml.PrettyPrintWriter;
+import com.thoughtworks.xstream.io.xml.StaxDriver;
 import de.neemann.digital.analyse.expression.BitSetter;
 import de.neemann.digital.analyse.expression.Context;
 import de.neemann.digital.analyse.expression.ExpressionException;
@@ -7,6 +10,7 @@ import de.neemann.digital.analyse.expression.Variable;
 import de.neemann.digital.analyse.quinemc.BoolTable;
 import de.neemann.digital.analyse.quinemc.BoolTableIntArray;
 
+import java.io.*;
 import java.util.ArrayList;
 
 /**
@@ -18,7 +22,45 @@ public class TruthTable {
 
     private final ArrayList<Variable> variables;
     private final ArrayList<Result> results;
-    private BitSetter bitSetter;
+    private transient BitSetter bitSetter;
+
+    /**
+     * Load the given file and returns a truth table instance
+     *
+     * @param filename filename
+     * @return the {@link TruthTable}
+     * @throws IOException IOException
+     */
+    public static TruthTable readFromFile(File filename) throws IOException {
+        XStream xStream = getxStream();
+        try (InputStream in = new FileInputStream(filename)) {
+            return (TruthTable) xStream.fromXML(in);
+        }
+    }
+
+    /**
+     * Writes the table to the given file.
+     *
+     * @param filename the file
+     * @throws IOException IOException
+     */
+    public void save(File filename) throws IOException {
+        XStream xStream = getxStream();
+        try (Writer out = new OutputStreamWriter(new FileOutputStream(filename), "utf-8")) {
+            out.write("<?xml version=\"1.0\" encoding=\"utf-8\"?>\n");
+            xStream.marshal(this, new PrettyPrintWriter(out));
+        }
+    }
+
+    private static XStream getxStream() {
+        XStream xStream = new XStream(new StaxDriver());
+        xStream.alias("truthTable", TruthTable.class);
+        xStream.alias("variable", Variable.class);
+        xStream.aliasAttribute(Variable.class, "identifier", "name");
+        xStream.alias("result", Result.class);
+        xStream.alias("BoolTable", BoolTableIntArray.class);
+        return xStream;
+    }
 
     /**
      * Creates a new instance

src/main/java/de/neemann/digital/gui/Main.java

@@ -755,7 +755,14 @@ public class Main extends JFrame implements ClosingWindowListener.ConfirmSave, E
             setTitle(Lang.get("digital"));
     }
 
-    private static File checkSuffix(File filename, String suffix) {
+    /**
+     * Adds the given suffix to the file
+     *
+     * @param filename filename
+     * @param suffix   suffix
+     * @return the file name with the given suffix
+     */
+    public static File checkSuffix(File filename, String suffix) {
         String name = filename.getName();
         int p = name.lastIndexOf('.');
         if (p >= 0)

src/main/java/de/neemann/digital/gui/components/table/TableDialog.java

@@ -61,7 +61,7 @@ public class TableDialog extends JDialog {
     private final JPopupMenu renamePopup;
     private final Font font;
     private final ShapeFactory shapeFactory;
-    private final File filename;
+    private File filename;
     private TruthTableTableModel model;
     private TableColumn column;
     private int columnIndex;
@@ -122,6 +122,44 @@ public class TableDialog extends JDialog {
 
         JMenu fileMenu = new JMenu(Lang.get("menu_file"));
 
+        fileMenu.add(new ToolTipAction(Lang.get("menu_open")) {
+            @Override
+            public void actionPerformed(ActionEvent e) {
+                JFileChooser fc = new JFileChooser();
+                if (TableDialog.this.filename != null)
+                    fc.setSelectedFile(Main.checkSuffix(TableDialog.this.filename, "tru"));
+                if (fc.showOpenDialog(TableDialog.this) == JFileChooser.APPROVE_OPTION) {
+                    try {
+                        File file = Main.checkSuffix(fc.getSelectedFile(), "tru");
+                        TruthTable truthTable = TruthTable.readFromFile(file);
+                        setModel(new TruthTableTableModel(truthTable));
+                        TableDialog.this.filename = file;
+                    } catch (IOException e1) {
+                        new ErrorMessage().addCause(e1).show(TableDialog.this);
+                    }
+                }
+            }
+        });
+
+        fileMenu.add(new ToolTipAction(Lang.get("menu_save")) {
+            @Override
+            public void actionPerformed(ActionEvent e) {
+                JFileChooser fc = new JFileChooser();
+                if (TableDialog.this.filename != null)
+                    fc.setSelectedFile(Main.checkSuffix(TableDialog.this.filename, "tru"));
+                if (fc.showSaveDialog(TableDialog.this) == JFileChooser.APPROVE_OPTION) {
+                    try {
+                        File file = Main.checkSuffix(fc.getSelectedFile(), "tru");
+                        model.getTable().save(file);
+                        TableDialog.this.filename = file;
+                    } catch (IOException e1) {
+                        new ErrorMessage().addCause(e1).show(TableDialog.this);
+                    }
+                }
+            }
+        });
+
+
         fileMenu.add(new ToolTipAction(Lang.get("menu_table_exportTableLaTeX")) {
             @Override
             public void actionPerformed(ActionEvent e) {
@@ -310,13 +348,7 @@ public class TableDialog extends JDialog {
         if (filename == null) {
             filename = new File("circuit.jed");
         } else {
-            String name = filename.getName();
+            filename = Main.checkSuffix(filename.getParentFile(), "jed");
-            if (filename.getName().endsWith(".dig")) {
-                name = name.substring(0, name.length() - 3) + "jed";
-            } else {
-                name += ".jed";
-            }
-            filename = new File(filename.getParentFile(), name);
         }
 
         JFileChooser fileChooser = new JFileChooser();
@@ -324,7 +356,7 @@ public class TableDialog extends JDialog {
         fileChooser.setSelectedFile(filename);
         if (fileChooser.showSaveDialog(this) == JFileChooser.APPROVE_OPTION) {
             try {
-                try (OutputStream out = new FileOutputStream(fileChooser.getSelectedFile())) {
+                try (OutputStream out = new FileOutputStream(Main.checkSuffix(fileChooser.getSelectedFile(), "jed"))) {
                     expressionExporter.getPinMapping().addAll(pinMap);
                     new BuilderExpressionCreator(expressionExporter.getBuilder(), ExpressionModifier.IDENTITY).create();
                     expressionExporter.writeTo(out);
@@ -359,14 +391,8 @@ public class TableDialog extends JDialog {
         fileChooser.setFileFilter(new FileNameExtensionFilter("PLD", "PLD"));
         if (fileChooser.showSaveDialog(this) == JFileChooser.APPROVE_OPTION) {
             try {
-                File f = fileChooser.getSelectedFile();
+                File f = Main.checkSuffix(fileChooser.getSelectedFile(), "PLD");
-                String name = f.getName();
+                cupl.setProjectName(f.getName());
-                if (!name.endsWith(".PLD"))
-                    name = name + ".PLD";
-
-                f = new File(f.getParentFile(), name);
-
-                cupl.setProjectName(name);
                 cupl.getPinMapping().addAll(pinMap);
                 new BuilderExpressionCreator(cupl.getBuilder(), ExpressionModifier.IDENTITY).create();
                 try (FileOutputStream out = new FileOutputStream(f)) {