java - 单击 Swing 菜单项时挂起系统

Question

我有一个问题，我创建了一个带有菜单栏的 Swing 应用程序，它在菜单中包含三个项目，但是当我单击一个菜单时，它会挂起，系统无法转到另一个菜单。只有强制关闭是最后一个选项。

下面是我的 StackTrace..任何人都可以知道错误在哪里吗？

    Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
    at com.openbravo.pos.perception.Per_panel.deactivate(Per_panel.java:211)
    at com.openbravo.pos.forms.JPrincipalApp.showTask(JPrincipalApp.java:344)
    at com.openbravo.pos.forms.MenuPanelAction.actionPerformed(MenuPanelAction.java:47)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
    at org.jdesktop.swingx.JXHyperlink.fireActionPerformed(JXHyperlink.java:266)
    at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
    at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
    at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
    at java.awt.Component.processMouseEvent(Component.java:6505)
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
    at java.awt.Component.processEvent(Component.java:6270)
    at java.awt.Container.processEvent(Container.java:2229)
    at java.awt.Component.dispatchEventImpl(Component.java:4861)
    at java.awt.Container.dispatchEventImpl(Container.java:2287)
    at java.awt.Component.dispatchEvent(Component.java:4687)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
    at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
    at java.awt.Container.dispatchEventImpl(Container.java:2273)
    at java.awt.Window.dispatchEventImpl(Window.java:2719)
    at java.awt.Component.dispatchEvent(Component.java:4687)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:729)
    at java.awt.EventQueue.access$200(EventQueue.java:103)
    at java.awt.EventQueue$3.run(EventQueue.java:688)
    at java.awt.EventQueue$3.run(EventQueue.java:686)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
    at java.awt.EventQueue$4.run(EventQueue.java:702)
    at java.awt.EventQueue$4.run(EventQueue.java:700)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:699)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)
    Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
    at com.openbravo.pos.perception.Per_panel.deactivate(Per_panel.java:211)
    at com.openbravo.pos.forms.JPrincipalApp.showTask(JPrincipalApp.java:344)
    at com.openbravo.pos.forms.MenuPanelAction.actionPerformed(MenuPanelAction.java:47)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
    at org.jdesktop.swingx.JXHyperlink.fireActionPerformed(JXHyperlink.java:266)
    at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
    at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
    at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
    at java.awt.Component.processMouseEvent(Component.java:6505)
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
    at java.awt.Component.processEvent(Component.java:6270)
    at java.awt.Container.processEvent(Container.java:2229)
    at java.awt.Component.dispatchEventImpl(Component.java:4861)
    at java.awt.Container.dispatchEventImpl(Container.java:2287)
    at java.awt.Component.dispatchEvent(Component.java:4687)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
    at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
    at java.awt.Container.dispatchEventImpl(Container.java:2273)
    at java.awt.Window.dispatchEventImpl(Window.java:2719)
    at java.awt.Component.dispatchEvent(Component.java:4687)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:729)
    at java.awt.EventQueue.access$200(EventQueue.java:103)
    at java.awt.EventQueue$3.run(EventQueue.java:688)
    at java.awt.EventQueue$3.run(EventQueue.java:686)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
    at java.awt.EventQueue$4.run(EventQueue.java:702)
    at java.awt.EventQueue$4.run(EventQueue.java:700)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:699)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)

错误代码

 public Per_panel() throws ClassNotFoundException {
        initComponents();


        try {
            Class.forName("com.mysql.jdbc.Driver");
            Connection con = (com.mysql.jdbc.Connection) DriverManager.getConnection("jdbc:mysql://localhost:3306/unicentadb", "root", "ubuntu123");
            Statement st = con.createStatement();
            ResultSet rs = st.executeQuery("Select NAME from PRODUCTS");



            while (rs.next()) {

            parts.addItem(rs.getString("NAME"));

            }
        } catch (SQLException ex) {
        }
        }

        @Override
        public void init(AppView app) throws BeanFactoryException {
        this.app = app;



        // m_ticketsbag = getJTicketsBag();
        // m_jPanelBag.add(m_ticketsbag.getBagComponent(), BorderLayout.LINE_START);
        // add(m_ticketsbag.getNullComponent(), "null");

        //    m_ticketlines = new JTicketLines(dlSystem.getResourceAsXML("Ticket.Line"));
        //  m_jPanelCentral.add(m_ticketlines, java.awt.BorderLayout.CENTER);

        //  m_TTP = new TicketParser(m_App.getDeviceTicket(), dlSystem);

        // Los botones configurables...
        // m_jbtnconfig = new JPanelButtons("Ticket.Buttons", this);
        // m_jButtonsExt.add(m_jbtnconfig);           

        //Panel products or lines ...  
        //    catcontainer.add(getSouthComponent(), BorderLayout.CENTER);

        // Tax model
        //  senttax = dlSales.getTaxList();
        //  senttaxcategories = dlSales.getTaxCategoriesList();

        //  taxcategoriesmodel = new ComboBoxValModel();    

        // ponemos a cero el estado
        //  stateToZero();  

        // inicializamos
        //  m_oTicket = null;
        //  m_oTicketExt = null; 



        }

        @Override
        public Object getBean() {
        return this;
        }

        @Override
        public String getTitle() {
        return AppLocal.getIntString("Menu.panel");
        }

        @Override
        public void activate() throws BasicException {
        //paymentdialog = JPaymentSelectCustomer.getDialog(this);
        //paymentdialog.init(app);


        }

        @Override
        public boolean deactivate() {
           return m_ticketsbag.deactivate();//To change body of generated methods, choose Tools | Templates.
        }





        @Override
        public JComponent getComponent() {
        return this;

        }

        private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {                                         


        try {

            //   int count = jTable1.getRowCount();
            // int count1 = jTable1.getColumnCount();


            Class.forName("com.mysql.jdbc.Driver");
            Connection con = (Connection) DriverManager.getConnection("jdbc:mysql://localhost:3306/unicentadb", "root", "ubuntu123");



            // running varchar date String d1 = ((JTextField) jDateChooser1.getDateEditor().getUiComponent()).getText();
            //System.out.println(d1); 
            //ResultSet rs = null;
            //  String dateValue = rs.getString(1,jDateChooser1); // What ever column
            // String dateValue = jDateChooser1.getDateFormatString();
            // java.util.Date jd = new SimpleDateFormat("dd.MM.yyyy HH:mm:ss").parse(dateValue);

            String tf1 = perf.getText();
            String tf2 = reason.getText();
            String tf3 = fees.getText();
            java.util.Date jd = date.getDate();
            String tf5 = (String) parts.getSelectedItem();
            //  String tf9 = jTextField2.getText();
            PreparedStatement pstmt = (PreparedStatement) con.prepareStatement("insert into MobileRep(pronumber,Reason,fees,delivery,parts) values(?,?,?,?,?)");
            //running varchar date  pstmt.setString(1, d1);

            pstmt.setString(1, tf1);
            pstmt.setString(2, tf2);
            pstmt.setString(3, tf3);
            pstmt.setDate(4, new java.sql.Date(jd.getTime()));
            pstmt.setString(5, tf5);

            //   pstmt.setString(9,tf9);

            pstmt.executeUpdate();
            pstmt.close();

            con.close();
        } catch (Exception e)
        {
            System.out.println("Exception.." + e);
        }



        }                                        

        private void jButton4ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        int i;
        long value;
        String output = "";

        for (i = 1; i <= 1; i++) {

            value = (new Date()).getTime();


            //value = Math.random( );
            output = output + "\t" + value + "\n";
            perf.setText(output);

        }


        }                                        

Answer 1

    @Override
    public boolean deactivate() {
     return true;
    }

使用这个方法问题就可以解决。