...

                .setAcceptAllFileFilterUsed(true)

                .showOpenDialog();

        System.out.println("AAA");

        if (file== null) {

            System.out.print("No file chosen.");

        } else {

<?xml version="1.0" encoding="UTF-8" ?>

<!--

    Licensed to the Apache Software Foundation (ASF) under one

    or more contributor license agreements.  See the NOTICE file

    distributed with this work for additional information

    regarding copyright ownership.  The ASF licenses this file

    to you under the Apache License, Version 2.0 (the

    "License"); you may not use this file except in compliance

    with the License.  You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing,

    software distributed under the License is distributed on an

    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

    KIND, either express or implied.  See the License for the

    specific language governing permissions and limitations

    under the License.

-->

<Form version="1.5" maxVersion="1.9" type="org.netbeans.modules.form.forminfo.JPanelFormInfo">

  <AuxValues>

    <AuxValue name="FormSettings_autoResourcing" type="java.lang.Integer" value="1"/>

    <AuxValue name="FormSettings_autoSetComponentName" type="java.lang.Boolean" value="false"/>

    <AuxValue name="FormSettings_generateFQN" type="java.lang.Boolean" value="true"/>

    <AuxValue name="FormSettings_generateMnemonicsCode" type="java.lang.Boolean" value="true"/>

    <AuxValue name="FormSettings_i18nAutoMode" type="java.lang.Boolean" value="true"/>

    <AuxValue name="FormSettings_layoutCodeTarget" type="java.lang.Integer" value="1"/>

    <AuxValue name="FormSettings_listenerGenerationStyle" type="java.lang.Integer" value="0"/>

    <AuxValue name="FormSettings_variablesLocal" type="java.lang.Boolean" value="false"/>

    <AuxValue name="FormSettings_variablesModifier" type="java.lang.Integer" value="2"/>

  </AuxValues>

  <Layout>

    <DimensionLayout dim="0">

      <Group type="103" groupAlignment="0" attributes="0">

          <EmptySpace min="0" pref="400" max="32767" attributes="0"/>

      </Group>

    </DimensionLayout>

    <DimensionLayout dim="1">

      <Group type="103" groupAlignment="0" attributes="0">

          <EmptySpace min="0" pref="300" max="32767" attributes="0"/>

      </Group>

    </DimensionLayout>

  </Layout>

</Form>

/*

 * To change this license header, choose License Headers in Project Properties.

 * To change this template file, choose Tools | Templates

 * and open the template in the editor.

 */

package cz.fidentis.analyst.gui.core;

import org.netbeans.api.settings.ConvertAsProperties;

import org.openide.awt.ActionID;

import org.openide.awt.ActionReference;

import org.openide.windows.TopComponent;

import org.openide.util.NbBundle.Messages;

/**

 * Top component which displays something.

 */

@ConvertAsProperties(

        dtd = "-//cz.fidentis.analyst.gui.core//ControlPanel//EN",

        autostore = false

)

        @TopComponent.Description(

                preferredID = "ControlPanelTC",

                //iconBase="SET/PATH/TO/ICON/HERE",

                persistenceType = TopComponent.PERSISTENCE_ALWAYS

        )

        @TopComponent.Registration(mode = "properties", openAtStartup = true)

@ActionID(category = "Window", id = "cz.fidentis.analyst.gui.core.ControlPanelTC")

@ActionReference(path = "Menu/Window" /*, position = 333 */)

@TopComponent.OpenActionRegistration(

        displayName = "#CTL_ControlPanelAction",

        preferredID = "ControlPanelTopComponent"

)

@Messages({

    "CTL_ControlPanelAction=ControlPanel",

    "CTL_ControlPanelTopComponent=Control Panel",

    "HINT_ControlPanelTopComponent=This is a ControlPanel window"

})

public final class ControlPanelTC extends TopComponent {

    public ControlPanelTC() {

        initComponents();

        setName(Bundle.CTL_ControlPanelTopComponent());

        setToolTipText(Bundle.HINT_ControlPanelTopComponent());

    }

    /**

     * This method is called from within the constructor to initialize the form.

     * WARNING: Do NOT modify this code. The content of this method is always

     * regenerated by the Form Editor.

     */

    // <editor-fold defaultstate="collapsed" desc="Generated Code">//GEN-BEGIN:initComponents

    private void initComponents() {

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);

        this.setLayout(layout);

        layout.setHorizontalGroup(

            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)

            .addGap(0, 400, Short.MAX_VALUE)

        );

        layout.setVerticalGroup(

            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)

            .addGap(0, 300, Short.MAX_VALUE)

        );

    }// </editor-fold>//GEN-END:initComponents

    // Variables declaration - do not modify//GEN-BEGIN:variables

    // End of variables declaration//GEN-END:variables

    @Override

    public void componentOpened() {

        // TODO add custom code on component opening

    }

    @Override

    public void componentClosed() {

        // TODO add custom code on component closing

    }

    void writeProperties(java.util.Properties p) {

        // better to version settings since initial version as advocated at

        // http://wiki.apidesign.org/wiki/PropertyFiles

        p.setProperty("version", "1.0");

        // TODO store your settings

    }

    void readProperties(java.util.Properties p) {

        String version = p.getProperty("version");

        // TODO read your settings according to their version

    }

}