三、實例

（1）打開、關閉串口

首先使用CommPortIdentifier中的方法，獲取可用的端口，并且選擇一個端口打開作為通信端口。

A:枚舉可用端口

?

1?	void?listPortChoices()?
2?	{
3?	?????CommPortIdentifier?portId;
4?	?????Enumeration?en?=?CommPortIdentifier.getPortIdentifiers();
5?	??????while?(en.hasMoreElements())?
6?	???????{
7?	?????????portId?=?(CommPortIdentifier)?en.nextElement();
8?	?????????if?(portId.getPortType()?==?CommPortIdentifier.PORT_SERIAL)?
9?	?????????System.out.println(portId.getName());
10?	???????}
11?	???????portChoice.select(parameters.getPortName());
12?	?}
13?	?
14?	?

?

B:打開指定的端口

1?	CommPortIdentifier?portId;
2?	try?
3?	{
4?	??//生成CommPortIdentifier類的實例
5?	??portId?=?CommPortIdentifier.getPortIdentifier("COM4");
6?	}?
7?	catch?(NoSuchPortException?e)
8?	{
9?	???e.printStackTrace();
10?	}
11?	try?
12?	{
13?	????//打開串口COM4,設置超時時限為3000毫秒
14?	??? serialPort?=?(SerialPort)?portId.open("testApp",?3000);
15?	}?
16?	catch?(PortInUseException?e)
17?	{
18?	??? e.printStackTrace();
19?	}
20?	?
21?	?

?

C:關閉端口

使用完的端口，必須記得將其關閉，否則其它的程序將無法使用該端口，CommPortIdentifier類只提供了開啟端口的方法，而要關閉端口，則要調用CommPort類的close()方法。

serialPort.close()

（2）設置串口參數

1?	try?{
2?	??? try?{
3?	??? ??? serialPort.setSerialPortParams(9600,?//? 波特率
4?	??? ??? ???????????????????????????????SerialPort.DATABITS_8,//? 數據位數
5?	??? ???????????????????????????????????SerialPort.STOPBITS_1,?//? 停止位
6?	??? ???????????????????????????????????SerialPort.PARITY_NONE);//? 奇偶位
7?	??? }?
8?	??? catch?(UnsupportedCommOperationException?e)
9?	??? ?{
10?	??? ??? e.printStackTrace();
11?	??? }
12?	?

(3)串口的讀、寫

A:向串口寫數據

1?	??? OutputStream?outputStream;
2?	??? try
3?	??? {
4?	??? ??? outputStream?=?serialPort.getOutputStream();
5?	??? }?
6?	??? catch?(IOException?e)
7?	??? ?{
8?	??? ??? e.printStackTrace();
9?	??? }
10?	??? bt?=?new?byte[]?{?(byte)?0x55,?(byte)?0xAA,?(byte)?0xF1?};
11?	??? try
12?	??? {
13?	??? ??? outputStream.write(bt);
14?	??? ??? outputStream.flush();
15?	??? ??? outputStream.close();
16?	??? }
17?	??? catch?(IOException?e)
18?	??? ?{
19?	??? ??? e.printStackTrace();
20?	??? }
21?	?

B:讀取串口中的數據

讀操作，需繼承SerialPortEventListener接口。為SerialPort添加監聽Listener。實現該接口的serialEvent (SerialPortEvent event)方法。

1?	??? ??? public?class?SerialRead?implements?SerialPortEventListener{
2?	??? ???
3?	??? ??? ??? InputStream?inputStream;
4?	??? ??? ??? byte[]?rBuffer?=?new?byte[38];
5?	??? ??? ??? ?SerialRead(SerialPort?serialPort)
6?	??? ??? ??? ?{
7?	??? ??? ??? ??? try?{
8?	??? ??? ??? ??? ??? serialPort.addEventListener((SerialPortEventListener)?this);
9?	??? ??? ??? ??? ??? this.serialPort.notifyOnDataAvailable(true);
10?	??? ???
11?	??? ??? ??? ??? }?catch?(TooManyListenersException?e)?{
12?	??? ??? ??? ??? }
13?	??? ??? ???
14?	??? ??? ??? ??? try?{
15?	??? ??? ??? ??? ??? if?(serialPort?!=?null)
16?	??? ??? ??? ??? ??? ??? inputStream?=?serialPort.getInputStream();
17?	??? ??? ??? ??? }?catch?(IOException?e)?{
18?	??? ??? ??? ??? }
19?	??? ??? ??? ????}
20?	??? ??? ??? ?
21?	??? ??? ??? public?void?serialEvent(SerialPortEvent?event)?
22?	??? ??? ??? {
23?	??? ??? ??? ??? if?(event.getEventType()?==?SerialPortEvent.DATA_AVAILABLE)
24?	??? ??? ??? ??? {?
25?	??? ??? ??? ??? ??? int?count?=?0;
26?	??? ??? ??? ??? ??? try?
27?	??? ??? ??? ??? ??? {
28?	??? ??? ??? ??? ??? ??? while?((ch?=?inputStream.read())?!=?-1)?
29?	??? ??? ??? ??? ??? ??? {??? ???
30?	??? ??? ??? ??? ??? ??? ??? bt[count++]=(byte)ch;
31?	??? ??? ??? ??? ??? ??? }
32?	??? ??? ??? ??? ??? }
33?	??? ??? ??? ??? ??? catch?(IOException?e)?
34?	??? ??? ??? ??? ??? {
35?	??? ??? ??? ??? ??? ??? e.printStackTrace();
36?	??? ??? ??? ??? ??? }
37?	??? ??? ??? ??? }???
38?	??? ??? ??? }
39?	?

總結

以上是生活随笔為你收集整理的JAVA 串口编程（二）的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。