当端口存在时，为什么我会收到 Java NoSuchPortException?

Got the following production code below, I'm using it for a new driver. portName is COM4 and this port exists on the PC (and I can connect to it with hyperterminal), so why does Javacomm throw a NoSuchPortException? COM4 shows up fine in device mgr. too

    final String portName = getSerialPort();
    try {
        final CommPortIdentifier id = CommPortIdentifier.getPortIdentifier(portName);
        port = (SerialPort) id.open(getName(), 1000);
    } catch (NoSuchPortException nspe) {
        report(SeverityCode.LEVEL2, getName(), "PIN Pad is not connected to " + portName + " port, or the port does not exist.");
        return;
    } catch (PortInUseException piue) {
        report(SeverityCode.LEVEL2, getName(), portName + " port is already in-use by some other device. Reason: " + piue.getMessage());
        return;
    }

推荐答案

尝试使用 CommPortIdentifier.getPortIdentifiers() 枚举系统上可用的端口列表并打印列出的内容.您确定将 jarfiles 和 dll 安装在正确的文件夹中吗?如果是，则尝试使用 CommPortIdentifier.addPortName(java.lang.String portName, int portType, CommDriver driver) 添加 COM4.您可以将驱动程序参数设置为 null 以使用默认驱动程序.