EDIT

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.IOException;

import java.util.Properties;

import org.eclipse.nebula.widgets.nattable.persistence.PersistenceHelper;

import org.eclipse.nebula.widgets.nattable.persistence.command.DisplayPersistenceDialogCommand;

import org.eclipse.nebula.widgets.nattable.persistence.command.IStateChangedListener;

import org.eclipse.nebula.widgets.nattable.persistence.command.StateChangeEvent;

import org.eclipse.swt.widgets.Combo;

import eu.etaxonomy.taxeditor.workbench.WorkbenchUtility;

    private static final String CHARACTER_MATRIX_STATE_PROPERTIES = "characterMatrixState.properties";

        /**

         * CONFIGURATION

         */

        /**

         * Table state persistence

         */

        Properties natTableState = new Properties();

        //load persisted state

        File statePropertiesFile = new File(WorkbenchUtility.getBaseLocation(), CHARACTER_MATRIX_STATE_PROPERTIES);

        FileInputStream inputStream;

        try {

            inputStream = new FileInputStream(statePropertiesFile);

            natTableState.load(inputStream);

            natTable.loadState("", natTableState);

        } catch (IOException e) {

            MessagingUtils.error(CharacterMatrix.class, e);;e.printStackTrace();

        }

        DisplayPersistenceDialogCommandHandler handler =

                new DisplayPersistenceDialogCommandHandler(natTableState, natTable);

        gridLayer.registerCommandHandler(handler);

     // create a combobox for showing the available view states

        Combo viewStates = new Combo(parent, SWT.DROP_DOWN);

        viewStates.setItems(PersistenceHelper

                .getAvailableStates(natTableState)

                .toArray(new String[] {}));

        viewStates.addSelectionListener(new SelectionAdapter() {

            @Override

            public void widgetSelected(SelectionEvent e) {

                int index = viewStates.getSelectionIndex();

                if (index >= 0) {

                    String selected = viewStates.getItem(index);

                    // load the state

                    natTable.loadState(selected, natTableState);

                }

            }

        });

        // add listener to update the combo on view state management changes

        handler.addStateChangeListener(new IStateChangedListener() {

            @Override

            public void handleStateChange(StateChangeEvent event) {

                viewStates.setItems(PersistenceHelper

                        .getAvailableStates(natTableState)

                        .toArray(new String[] {}));

            }

        });

        // add button to show dialog

        Button manage = new Button(parent, SWT.PUSH);

        manage.setText("View Management");

        manage.addSelectionListener(new SelectionAdapter() {

            @Override

            public void widgetSelected(SelectionEvent e) {

                natTable.doCommand(new DisplayPersistenceDialogCommand(natTable));

            }

        });

        Button btnSave = new Button(parent, SWT.PUSH);

        btnSave.setText("Save State");

        btnSave.addSelectionListener(new SelectionAdapter() {

            @Override

            public void widgetSelected(SelectionEvent e) {

                natTable.saveState("", natTableState);

                try (FileOutputStream tableStateStream =

                        new FileOutputStream(new File(WorkbenchUtility.getBaseLocation(), CHARACTER_MATRIX_STATE_PROPERTIES))) {

                    natTableState.store(tableStateStream, null);

                } catch (IOException ioe) {

                    ioe.printStackTrace();

                }

            }

        });

        /**

         * excel export

         */