Java RS232 communication using Swing and RXTX -

i'm trying communicate between pc (windows 7 using netbeans , rxtx) using serial port. have prolem serial event(public void serialevent(serialportevent arg0)). event should recive data , write them in label (jlabel1.settext("sfazds")). unfortunately event don't change label text , don't why. below code:

import gnu.io.commport; import gnu.io.commportidentifier; import gnu.io.serialport; import gnu.io.serialportevent; import gnu.io.serialporteventlistener; import java.io.ioexception; import java.io.inputstream; import java.io.outputstream; import javax.swing.jlabel; import javax.swing.joptionpane; import javax.swing.jpanel;  public class rs extends javax.swing.jframe implements serialporteventlistener{      static outputstream out;     static inputstream in;      public rs() {         initcomponents();     }      /**      * method called within constructor initialize form.      * warning: not modify code. content of method      * regenerated form editor.      */     @suppresswarnings("unchecked")     // <editor-fold defaultstate="collapsed" desc="generated code">                               private void initcomponents() {          jbutton1 = new javax.swing.jbutton();         jlabel1 = new javax.swing.jlabel();          setdefaultcloseoperation(javax.swing.windowconstants.exit_on_close);         addwindowlistener(new java.awt.event.windowadapter() {             public void windowopened(java.awt.event.windowevent evt) {                 formwindowopened(evt);             }         });          jbutton1.settext("jbutton1");         jbutton1.addactionlistener(new java.awt.event.actionlistener() {             public void actionperformed(java.awt.event.actionevent evt) {                 jbutton1actionperformed(evt);             }         });          jlabel1.settext("jlabel1");          javax.swing.grouplayout layout = new javax.swing.grouplayout(getcontentpane());         getcontentpane().setlayout(layout);         layout.sethorizontalgroup(             layout.createparallelgroup(javax.swing.grouplayout.alignment.leading)             .addgroup(layout.createsequentialgroup()                 .addgroup(layout.createparallelgroup(javax.swing.grouplayout.alignment.leading)                     .addgroup(layout.createsequentialgroup()                         .addgap(54, 54, 54)                         .addcomponent(jbutton1))                     .addgroup(layout.createsequentialgroup()                         .addgap(203, 203, 203)                         .addcomponent(jlabel1)))                 .addcontainergap(217, short.max_value))         );         layout.setverticalgroup(             layout.createparallelgroup(javax.swing.grouplayout.alignment.leading)             .addgroup(layout.createsequentialgroup()                 .addgap(21, 21, 21)                 .addcomponent(jbutton1)                 .addgap(34, 34, 34)                 .addcomponent(jlabel1)                 .addcontainergap(222, short.max_value))         );          pack();     }// </editor-fold>                              private void jbutton1actionperformed(java.awt.event.actionevent evt) {                                                  byte[] b = new byte[2];         b[0] = 'a';         b[1] = 'b';         try{             out.write(b);         }         catch(exception e){             e.printstacktrace();         }     }                                              private void formwindowopened(java.awt.event.windowevent evt) {                                           try{             (new rs()).connect("com3");         }         catch(exception e){             e.printstacktrace();         }     }                                       void connect(string portname) throws exception{         commportidentifier portidentifier = commportidentifier.getportidentifier(portname);         if (portidentifier.iscurrentlyowned()){             joptionpane.showmessagedialog(null, "błąd: port jest obecnie w użyciu");         }         else{             commport commport = portidentifier.open(this.getclass().getname(), 2000);             if (commport instanceof serialport){                 serialport serialport = (serialport) commport;                 serialport.setserialportparams(57600,serialport.databits_8,serialport.stopbits_1,serialport.parity_none);                  in = serialport.getinputstream();                 out = serialport.getoutputstream();                  (new thread(new serialwriter(out))).start();                 serialport.addeventlistener(this);                 serialport.notifyondataavailable(true);             }                  else{                 joptionpane.showmessagedialog(null, "tylko port szeregowy może być podłączony!");             }         }     }     @override     public void serialevent(serialportevent arg0) {             int data;             byte[] buffer = new byte[1024];             try{                 int len = 0;                 while ( ( data = in.read()) > -1 ){                     if ( data == '\n' ) {                         break;                     }                     buffer[len++] = (byte) data;                 }                 system.out.print(new string(buffer,0,len));                 jlabel1.settext("sfazds");                 joptionpane.showmessagedialog(null, new string(buffer,0,len));             }             catch ( ioexception e ){                 system.exit(-1);             }                      }      public static class serialwriter implements runnable{         outputstream out;          public serialwriter(outputstream out){             this.out = out;         }          @override         public void run(){             try{                 int c = 0;                 while ((c = system.in.read()) > -1){                     this.out.write(c);                 }             }             catch(ioexception e){                 system.exit(-1);             }         }     }      public static void main(string args[]) {         /* set nimbus , feel */         //<editor-fold defaultstate="collapsed" desc=" , feel setting code (optional) ">         /* if nimbus (introduced in java se 6) not available, stay default , feel.          * details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html           */         try {             (javax.swing.uimanager.lookandfeelinfo info : javax.swing.uimanager.getinstalledlookandfeels()) {                 if ("nimbus".equals(info.getname())) {                     javax.swing.uimanager.setlookandfeel(info.getclassname());                     break;                 }             }         } catch (classnotfoundexception ex) {             java.util.logging.logger.getlogger(rs.class.getname()).log(java.util.logging.level.severe, null, ex);         } catch (instantiationexception ex) {             java.util.logging.logger.getlogger(rs.class.getname()).log(java.util.logging.level.severe, null, ex);         } catch (illegalaccessexception ex) {             java.util.logging.logger.getlogger(rs.class.getname()).log(java.util.logging.level.severe, null, ex);         } catch (javax.swing.unsupportedlookandfeelexception ex) {             java.util.logging.logger.getlogger(rs.class.getname()).log(java.util.logging.level.severe, null, ex);         }         //</editor-fold>          /* create , display form */         java.awt.eventqueue.invokelater(new runnable() {             public void run() {                 new rs().setvisible(true);             }         });     }      // variables declaration - not modify                          private javax.swing.jbutton jbutton1;     private javax.swing.jlabel jlabel1;     // end of variables declaration                    } 

your output not synchronized eventdispatchertread. try following:

    swingutilities.invokelater(new runnable() {          @override         public void run() {             jlabel1.settext("sfazds");         }     });