问题描述

我正在尝试使用 Java 连接 ubuntu 上的串行应用程序
在搜索和阅读资源后，我在库中添加了 comm.jar 和 RXTXcomm.jar.
我使用以下代码来识别comports.在我的系统中有三个端口，但在 ports.hasMoreElements() 方法中显示为 false.
请查看代码并帮助我.

I'm trying to connect a serial application on ubuntu with Java
After searching and reading resources,I add comm.jar and RXTXcomm.jar in the library.
I use the following code to identify the comports. In my system there are three ports but it is showing false in ports.hasMoreElements() method.
Kindly look into the code and help me.

String wantedPortName = "/dev/ttya";
///dev/ttyS0  /dev/ttyS1   
Enumeration portIdentifiers = CommPortIdentifier.getPortIdentifiers();
CommPortIdentifier portId = null;  // will be set if port found
while (portIdentifiers.hasMoreElements())
{
    CommPortIdentifier pid = (CommPortIdentifier) portIdentifiers.nextElement();
    if(pid.getPortType() == CommPortIdentifier.PORT_SERIAL &&
      pid.getName().equals(wantedPortName)) 
  {
    portId = pid;
    break;
  }
}
if(portId == null)
{
     System.err.println("Could not find serial port " + wantedPortName);
     System.exit(1);
}    

推荐答案

就我而言，我使用的是 Ubuntu，我的笔记本没有任何串行或并行端口.

In my case, I'm using Ubuntu, and my notebook does not have any serial or paralel ports.

所以，你必须模拟这种端口:

So, you have to simulate this kind of port:

apt-get install socat

运行它:

socat -d -d pty,raw,echo=0, pty,raw,echo=0

根据输出，注意创建的设备":

According to output, pay attention to "devices" created:

2014/02/05 01:04:32 socat[7411] N PTY is /dev/pts/2
2014/02/05 01:04:32 socat[7411] N PTY is /dev/pts/3
2014/02/05 01:04:32 socat[7411] N starting data transfer loop with FDs [3,3] and [5,5]

停止 socat [CTRL]+[C] 并将其符号链接到 RXTX 将识别为设备的位置，由于tty"前缀:

Stop socat [CTRL]+[C] and symlink it to a location that RXTX will recognise as a device, due to "tty" prefix:

sudo ln -s /dev/pts/2 /dev/ttyUSB02
sudo ln -s /dev/pts/3 /dev/ttyUSB03

现在，再次运行 socat

Now, run socat again

socat -d -d pty,raw,echo=0 pty,raw,echo=0

现在，使用以下代码，您将看到 2 个虚拟端口:

Now, using following code, you will see 2 virtual ports:

        Enumeration portList = CommPortIdentifier.getPortIdentifiers();//this line was false
        System.out.println(portList.hasMoreElements());

        while(portList.hasMoreElements()){
            System.out.println("Has more elements");
             CommPortIdentifier portId = (CommPortIdentifier) portList.nextElement();
               if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) {
                    System.out.println(portId.getName());
               }
               else{
                     System.out.println(portId.getName());
               }
        }

system.out:

system.out:

true
Has more elements
/dev/ttyUSB03
Has more elements
/dev/ttyUSB02

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