将所有端口列为JComboBox

Question

我有一个应用程序，我必须列出与Arduino连接的可用端口。我正在使用RxTx。我在当前代码中遇到问题： 在我的GUI中，我从这一行收到所有端口为ArrayList

public ArrayList<String> getPortIdentifiers() {
         Enumeration portEnum = CommPortIdentifier.getPortIdentifiers();
         ArrayList<String> ports = new ArrayList<String>();

         while (portEnum.hasMoreElements()) {
            CommPortIdentifier currPortId = (CommPortIdentifier) portEnum.nextElement();
                ports.add(currPortId.getName());
         }
            return ports;
    }

在我的控制器中，我得到了这个结果，并将结果设置为视图

this.view.setListPorts(listPorts);

在我看来，我得到了ArrayList并将数组设置为ComboBox

new JComboBox(this.listPorts.toArray());
public void setListPorts(ArrayList<String> ports) {
                this.listPorts = ports;
            }

但是我在这个行号上收到错误

  

线程中的异常“AWT-EventQueue-0”java.lang.NullPointerException

Answer 1

以下是更多代码：

public class CommunicationController implements ActionListener {
 public CommunicationController() throws IOException, TooManyListenersException {
       // initialize connection here
        this.communication = new TestComunication();
        ArrayList<String> listPorts = this.communication.getPortIdentifiers();
      this.view.setListPorts(listPorts);
 }
}

...

public class CommunicationView extends JPanel {
   private JComboBox portsList;
   private ArrayList<String> listPorts;

    public CommunicationView() {
   ....
   ..... 
 this.portsList = new JComboBox(this.listPorts.toArray());
}
 public void setListPorts(ArrayList<String> ports) {
        this.listPorts = ports;
    }
}

.....

public class TestComunication {
    public ArrayList<String> getPortIdentifiers() {
         Enumeration portEnum = CommPortIdentifier.getPortIdentifiers();
         ArrayList<String> ports = new ArrayList<String>();

         while (portEnum.hasMoreElements()) {
            CommPortIdentifier currPortId = (CommPortIdentifier) portEnum.nextElement();
                ports.add(currPortId.getName());
         }
            return ports;
    }
}

错误