java 读取串口数据

Question

比如说我发送:abcdefg我的接收段: read.java会报出a, 在报出 bcdefg   请问有哪位高手知道是怎么回事

Answer 1

难道 csdn 的高手,,,都还没上班?

Answer 2

把 我的接收段: read.java  里面的内容贴出来

Answer 3

read.java 主要代码如下:
public void connectPort(){

if(this.serialPort !=null){

this.serialPort.close();

}

try
{
portId = CommPortIdentifier.getPortIdentifier(this.portName);
serialPort = (SerialPort) portId.open("ReadComm", 2000); 
this.p3f2.setText(this.portName+" Success\n");


}catch(Exception ee){

JOptionPane.showMessageDialog(this,ee.toString(),"Message",JOptionPane.INFORMATION_MESSAGE);
this.p3f2.setText(this.portName+" failure\n");
}
try
{
serialPort.setSerialPortParams(9600,SerialPort.DATABITS_8,SerialPort.STOPBITS_1,SerialPort.PARITY_NONE); 

}catch(Exception ee){

JOptionPane.showMessageDialog(this,"Please connect serial port first!","Message",JOptionPane.INFORMATION_MESSAGE);
}

try{

this.inputStream = serialPort.getInputStream();
this.serialPort.addEventListener(this);

}catch(Exception ee){


}

serialPort.notifyOnDataAvailable(true);

}

public void WritePortData(String str){

try{

outputStream = serialPort.getOutputStream(); 
outputStream.write(str.getBytes());

}catch(Exception ee){

JOptionPane.showMessageDialog(this,ee.toString(),"Message",JOptionPane.INFORMATION_MESSAGE);
}


}
public void serialEvent(SerialPortEvent event) {

switch(event.getEventType()){

case SerialPortEvent.BI:
case SerialPortEvent.OE:
case SerialPortEvent.FE:
case SerialPortEvent.PE:
case SerialPortEvent.CD:
case SerialPortEvent.CTS:
case SerialPortEvent.DSR:
case SerialPortEvent.RI:
case SerialPortEvent.OUTPUT_BUFFER_EMPTY:
break;
case SerialPortEvent.DATA_AVAILABLE:
  byte[] readBuffer =  new byte[21];        
              try{  
                     
               while(inputStream.available()>0){
               
                      int numBytes=inputStream.read(readBuffer);                      
                   
               }
               
              // JOptionPane.showMessageDialog(this, new   String(readBuffer),"当前接收字符",JOptionPane.ERROR_MESSAGE);
               
               /*模拟在屏上显示,内容从单片机中接收*/
               this.dp.tme1.stop();
               this.dp.tme2.stop();
               
               String comStr = new String(readBuffer).trim();      //主要是这里它会分两次显示....比如说我接到到123456789 先显示1 在显示2345678...问题出在哪里
               System.out.println(comStr.length());
               
               if(comStr.length()>15){
               
               this.dp.tme1.start();
               
               
               }
               
               this.f.str=comStr;
               this.f.strcopy = comStr;
               
               this.f.stri = "";
               this.f.stricopyi = "";
               
               f.repaint();
               
          
               
               
                         
              }catch(Exception e){
               
               
              }
              
              
              
              break;   

}



}

Answer 4

while(inputStream.available()>0){
  int numBytes=inputStream.read(readBuffer);                      
}
这样的while有意义吗？每次都覆盖前面的数据
numBytes值有看过吗，每次是多少分两次显示会不会是多线程在读，没有看到循环的代码

Answer 5

bug 一下就OK了呀,在while这搞一个断点

Answer 6

我也遇到这个问题，用的moxa的串口卡，
每次只能读96,郁闷中呀，
你试试enableReceiveThreshold
看能不能接收问题，
我进行测试下，