[英]Open and Close Serial Ports
I am trying to connect to a Serial Port ... but once I open the Serial Port
in the first time. 我正在尝试连接到串行端口 ......但是一旦我第一次打开
Serial Port
。 I can't open it again, I've tried to apply. 我不能再打开它,我试着申请。 Here is my code:
这是我的代码:
public static void main(String[] args) {
portList = CommPortIdentifier.getPortIdentifiers();
while (portList.hasMoreElements()) {
portId = (CommPortIdentifier) portList.nextElement();
if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) {
if (portId.getName().equals("COM1")) {
try {
serialPort = (SerialPort)
portId.open("SimpleWriteApp", 2000);
} catch (PortInUseException e) {}
try {
outputStream = serialPort.getOutputStream();
} catch (IOException e) {}
try {
serialPort.setSerialPortParams(9600,
SerialPort.DATABITS_8,
SerialPort.STOPBITS_1,
SerialPort.PARITY_NONE);
} catch (UnsupportedCommOperationException e) {}
try {
outputStream.write(messageString.getBytes());
} catch (IOException e) {}
}
}
}
}
I want to close that port so I can use it for another task. 我想关闭该端口,以便我可以将它用于其他任务。
serialPort.close(); serialPort.close(); works for me.
适合我。 Be careful not to use the port again before closing it, as a lock file is written to the /var/lock Linux directory.
在关闭端口之前,请注意不要再次使用该端口,因为锁定文件将写入/ var / lock Linux目录。 In windows something similar I presume.
在Windows中我认为类似的东西。 This file has to be deleted before reopening the port.
在重新打开端口之前必须删除此文件。 Otherwise a nullPointerException will occur.
否则将发生nullPointerException。 Closing the port deletes this file.
关闭端口会删除此文件。
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