Java：引用另一个 class 中的构造函数

Question

I am trying to make a program, that automaticly extracts a link from a.json file. I'm new to programming, and I'm trying to organize the code, so other people will be able to understand it more easily.

I have a constructor called Gui, where it adds a close button, and a file explorer with awt. To organize the project, I want to make another class to extract the link, but I can't figure out, how I can refer to the TextField with the file path, in the Gui class's constructor.

I need to get the text from fe in another class.

I have searched the web for hours, but I can't find anything that works for me.

public class Gui extends Frame {

    public Gui() {
        Frame gui = new Frame(Strings.name);

        // add "close" button
        Button cls = new Button(Strings.close);
        cls.setBounds(30, 30, 100, 30);
        gui.add(cls);
        cls.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                System.exit(0);

            }
        });

        // file explorer
        TextField fe = new TextField(Strings.file);  
        fe.setBounds(50,100, 200,30);  
        fe.setLocation(75, 75);
        gui.add(fe);
        fe.addMouseListener(new MouseListener() {

            public void mouseReleased(MouseEvent e) {}

            public void mousePressed(MouseEvent e) {}

            public void mouseExited(MouseEvent e) {}

            public void mouseEntered(MouseEvent e) {}

            @Override
            public void mouseClicked(MouseEvent e) {
                FileDialog fd = new FileDialog(gui, Strings.cfile, FileDialog.LOAD);
                fd.setVisible(true);
                fe.setText(fd.getDirectory());
            }
        });

        // make application work
        gui.addWindowListener(new WindowAdapter(){  
               public void windowClosing(WindowEvent e) {  
                   System.exit(0);
               }  
        }); 

        gui.setSize(1200, 900);
        gui.setLayout(null);
        gui.setVisible(true);
    }

}

Answer 1

Could try with the following updates

public class Gui extends Frame {
//create an inner class
class MyProcess
{
    MyProcess(String s)
    {
        System.out.println("do something with s="+s);
    }
}

public static void main(String args[])
{
    new Gui();
}

...

@Override
public void mouseClicked(MouseEvent e) {
    FileDialog fd = new FileDialog(gui, "file", FileDialog.LOAD);
    fd.setVisible(true);
    fe.setText(fd.getDirectory());
    //use the inner class as needed
    new MyProcess(fe.getText());
    }

Possible output on console do something with s=D:\some_path\

Kindly note that is not mandatory an inner class, could be also an external one. That depends only of your design. Maybe also in the future for graphic interfaces you could do some researches on: JavaFx , Swing maybe Eclipse Graphics Library . Awt library is the most ancient one.

Answer 2

you should put your references to your classes eg text outside of your constructor for example,

public class Gui extends Frame {
// your reference
private TextField text;
Gui() {
// now instantiate your textField
text = new TextField();
}
// getter method that returns your textField
public TextField getTextField() {
return text;
}
}

then you can get your text from your gui.

Gui gui = new Gui();
TextField field =gui.getTextField();

I recommend that learn the basics of java programming and then define bigger project for your self.