Ping com java se

Estou aprendendo java se. Criei um jDialog com um campo jTextField, para digitar o site e retornar o ping em um jTextArea. Esta com erro… o que estou errando? Obrigado

private void btnPingActionPerformed(java.awt.event.ActionEvent evt) {                                        
     String site = txtWebSite.getText();
     String command = null;
     
     try {
            Process p = Runtime.getRuntime().exec(command);
            BufferedReader inputStream = new BufferedReader(
                            new InputStreamReader(p.getInputStream()));

            String s = "";
            // output do command
            while ((s = inputStream.readLine()) != null) {
                  jTextAreaResposta.setText("ping..."+ s);
            }

    } catch (Exception e) {
            e.printStackTrace();
    }
      
      
   runSystemCommand("ping " + site);
   
    
    }    

Erro:

run: java.lang.NullPointerException at java.lang.Runtime.exec(Runtime.java:443) at java.lang.Runtime.exec(Runtime.java:347) at Core.Reconnaissance.PingIP.btnPingActionPerformed(PingIP.java:99) at Core.Reconnaissance.PingIP.access$000(PingIP.java:15) at Core.Reconnaissance.PingIP$1.actionPerformed(PingIP.java:57) at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022) at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348) 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:6535) at javax.swing.JComponent.processMouseEvent(JComponent.java:3324) at java.awt.Component.processEvent(Component.java:6300) at java.awt.Container.processEvent(Container.java:2236) at java.awt.Component.dispatchEventImpl(Component.java:4891) at java.awt.Container.dispatchEventImpl(Container.java:2294) at java.awt.Component.dispatchEvent(Component.java:4713) at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4888) at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4525) at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4466) at java.awt.Container.dispatchEventImpl(Container.java:2280) at java.awt.Window.dispatchEventImpl(Window.java:2750) at java.awt.Component.dispatchEvent(Component.java:4713) at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758) at java.awt.EventQueue.access$500(EventQueue.java:97) at java.awt.EventQueue$3.run(EventQueue.java:709) at java.awt.EventQueue$3.run(EventQueue.java:703) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86) at java.awt.EventQueue$4.run(EventQueue.java:731) at java.awt.EventQueue$4.run(EventQueue.java:729) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) at java.awt.EventQueue.dispatchEvent(EventQueue.java:728) at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:109) at java.awt.WaitDispatchSupport$2.run(WaitDispatchSupport.java:184) at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:229) at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:227) at java.security.AccessController.doPrivileged(Native Method) at java.awt.WaitDispatchSupport.enter(WaitDispatchSupport.java:227) at java.awt.Dialog.show(Dialog.java:1084) at java.awt.Component.show(Component.java:1673) at java.awt.Component.setVisible(Component.java:1625) at java.awt.Window.setVisible(Window.java:1014) at java.awt.Dialog.setVisible(Dialog.java:1005) at Core.Reconnaissance.PingIP$2.run(PingIP.java:156) at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311) at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756) at java.awt.EventQueue.access$500(EventQueue.java:97) at java.awt.EventQueue$3.run(EventQueue.java:709) at java.awt.EventQueue$3.run(EventQueue.java:703) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) at java.awt.EventQueue.dispatchEvent(EventQueue.java:726) at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116) at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93) at java.awt.EventDispatchThread.run(EventDispatchThread.java:82) Exception in thread "AWT-EventQueue-0" java.lang.RuntimeException: Uncompilable source code - Erroneous sym type: Core.Reconnaissance.PingIP.runSystemCommand at Core.Reconnaissance.PingIP.btnPingActionPerformed(PingIP.java:114) at Core.Reconnaissance.PingIP.access$000(PingIP.java:15) at Core.Reconnaissance.PingIP$1.actionPerformed(PingIP.java:57) at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022) at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348) 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:6535) at javax.swing.JComponent.processMouseEvent(JComponent.java:3324) at java.awt.Component.processEvent(Component.java:6300) at java.awt.Container.processEvent(Container.java:2236) at java.awt.Component.dispatchEventImpl(Component.java:4891) at java.awt.Container.dispatchEventImpl(Container.java:2294) at java.awt.Component.dispatchEvent(Component.java:4713) at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4888) at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4525) at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4466) at java.awt.Container.dispatchEventImpl(Container.java:2280) at java.awt.Window.dispatchEventImpl(Window.java:2750) at java.awt.Component.dispatchEvent(Component.java:4713) at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758) at java.awt.EventQueue.access$500(EventQueue.java:97) at java.awt.EventQueue$3.run(EventQueue.java:709) at java.awt.EventQueue$3.run(EventQueue.java:703) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86) at java.awt.EventQueue$4.run(EventQueue.java:731) at java.awt.EventQueue$4.run(EventQueue.java:729) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) at java.awt.EventQueue.dispatchEvent(EventQueue.java:728) at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:109) at java.awt.WaitDispatchSupport$2.run(WaitDispatchSupport.java:184) at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:229) at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:227) at java.security.AccessController.doPrivileged(Native Method) at java.awt.WaitDispatchSupport.enter(WaitDispatchSupport.java:227) at java.awt.Dialog.show(Dialog.java:1084) at java.awt.Component.show(Component.java:1673) at java.awt.Component.setVisible(Component.java:1625) at java.awt.Window.setVisible(Window.java:1014) at java.awt.Dialog.setVisible(Dialog.java:1005) at Core.Reconnaissance.PingIP$2.run(PingIP.java:156) at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311) at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756) at java.awt.EventQueue.access$500(EventQueue.java:97) at java.awt.EventQueue$3.run(EventQueue.java:709) at java.awt.EventQueue$3.run(EventQueue.java:703) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) at java.awt.EventQueue.dispatchEvent(EventQueue.java:726) at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116) at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93) at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

vc diz que da erro mas nao mostra o mesmo, puxa… tsc tsc

o que eu imagino que é a variavel command nao foi inicializada. ai fica dificil para executar o ping…

Olá, já inicializei String command = null; Ainda esta com erro:

O erro é nessa linha: runSystemCommand("ping " + site);