串口实现

package comm;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import java.util.Enumeration;import javax.comm.CommPortIdentifier;import javax.comm.NoSuchPortException;import javax.comm.PortInUseException;import javax.comm.SerialPort;import javax.comm.SerialPortEvent;import javax.comm.SerialPortEventListener;import javax.comm.UnsupportedCommOperationException;public class portsent {public CommPortIdentifier portId;public  SerialPort serialPort;private String portname;private OutputStream outputStream;private InputStream inputStream;public portsent(){Enumeration<?> en = CommPortIdentifier.getPortIdentifiers();while (en.hasMoreElements()) {portId = (CommPortIdentifier) en.nextElement();// 如果端口类型是串口，则打印出其端口信息if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) {System.out.println(portId.getName());portname=portId.getName();}}if(portname==null)System.out.println("no port found");}public void openSerialPort() { // 获取要打开的端口try {portId = CommPortIdentifier.getPortIdentifier(portname);} catch (NoSuchPortException e) {System.out.println("抱歉,没有找到"+portname+"串行端口号!");return ;}// 打开端口try {serialPort = (SerialPort) portId.open("JavaRs232", 2000);System.out.println(portname+"串口已经打开!");} catch (PortInUseException e) {System.out.println(portname+"端口已被占用,请检查!");return ;}// 设置端口参数try {int rate = 9600;int data = 8;int stop = 1;int parity =0;serialPort.setSerialPortParams(rate,data,stop,parity);} catch (UnsupportedCommOperationException e) {System.out.println(e.getMessage());}// 打开端口的IO流管道 try { outputStream = serialPort.getOutputStream(); inputStream = serialPort.getInputStream(); } catch (IOException e) {System.out.println(e.getMessage());} serialPort.notifyOnDataAvailable(true); } public void sentmsg(String mesg){try { outputStream.write(mesg.getBytes()); outputStream.flush(); } catch (IOException e) { System.out.println(e.getMessage());} System.out.println("  发送: "+mesg);}public void closeSerialPort() {           try {               if(outputStream != null)                  outputStream.close();              if(serialPort != null)                  serialPort.close();            serialPort = null;              System.out.println(portname+"串口已经关闭!");          } catch (Exception e) {               System.out.println(e.getMessage());          }       }    }