import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;
import gnu.io.*;

 class S_Frame extends Frame implements Runnable,ActionListener
{ 
  /*檢測系統中可用的通訊端口類 */
  static CommPortIdentifier  portId; 
  /*Enumeration 為枚舉型類,在util中  */
  static Enumeration  portList; 
  OutputStream   outputStream;
  /*RS-232的串行口  */
  SerialPort  serialPort;    
  Thread  readThread;
  Panel  p=new Panel();
  TextField in_message=new  TextField("打開COM1,波特率9600,數據位8,停止位1.");
  TextArea  out_message=new TextArea(); 
  Button    btnOpen=new Button("打開串口,   發送數據");
  Button    btnClose=new Button("關閉串口, 停止發送數據");
  byte      data[]=new byte[10240];
    /*設置判斷要是否關閉串口的標志*/
  boolean   mark;

 /*安排窗體*/
 S_Frame()
 { super("串口發送數據");
   setSize(200,200);
   setVisible(true);
   add(out_message,"Center");
   add(p,"North");
   p.add(btnOpen);
   p.add(btnClose);
   add(in_message,"South");
   btnOpen.addActionListener(this);
   btnClose.addActionListener(this);
 } //R_Frame() end

 /*點擊按扭打開串口.*/
 public void actionPerformed(ActionEvent event) {
 if (event.getSource()==btnClose){
      serialPort.close();//關閉串口
      mark=true;  //用于中止線程的run()方法
        in_message.setText("串口COM1已經關閉,停止發送數據.");
   }
 else {  mark=false;
     /*從文本區按字節讀取數據*/
     data=out_message.getText().getBytes();
        /*打開串口*/
     start();
        in_message.setText("串口COM1已經打開,正在每20秒鐘發送一次數據.....");
      }
 } //actionPerformed() end

  /*打開串口,并調用線程發送數據*/
 public void start(){
  /*獲取系統中所有的通訊端口  */
  portList=CommPortIdentifier.getPortIdentifiers();
  /* 用循環結構找出串口 */
  while (portList.hasMoreElements()){  
   /*強制轉換為通訊端口類型*/
    portId=(CommPortIdentifier)portList.nextElement();
    if(portId.getPortType() == CommPortIdentifier.PORT_SERIAL){
      if (portId.getName().equals("COM1")) {
         /*打開串口 */
        try {
serialPort = (SerialPort) portId.open("ReadComm", 2000);
          } 
catch (PortInUseException e) {  }
           /*設置串口輸出流*/
        try { 
outputStream = serialPort.getOutputStream();
           } 
catch (IOException e) {}
      } //if end
     } //if end
   } //while end
   /*調用線程發送數據*/
  try{ 
     readThread = new Thread(this);
    //線程負責每發送一次數據，休眠20秒鐘
 readThread.start();
} 
catch (Exception e) {  }
 }  //start() end
 
  /*發送數據,休眠20秒鐘后重發*/
  public void run() {
    /*設置串口通訊參數*/
    try {
         serialPort.setSerialPortParams(9600,
                SerialPort.DATABITS_8,
                SerialPort.STOPBITS_1,
                SerialPort.PARITY_NONE);
        }
 catch (UnsupportedCommOperationException e) {  }
        /*發送數據流(將數組data[]中的數據發送出去)*/ 
  try { 
outputStream.write(data);
   }
catch (IOException e) {  }
        /*發送數據后休眠20秒鐘,然后再重發*/
  try { Thread.sleep(20000); 
       if (mark)
       {return;   //結束run方法,導致線程死亡
       }
       start();
      } 
       catch (InterruptedException e) {  }
   }  //run() end
}  //類S_Frame end

public class SendMessage
{public static void main(String args[])
 { S_Frame S_win=new S_Frame();
   S_win.addWindowListener(new WindowAdapter()
     {public void windowClosing(WindowEvent e)
      {System.exit(0);   }
     });
   S_win.pack();
 }
}