Java: Reference to constructor in another class

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);
}
}
</details>
# 答案1
**得分**: 0
```java
尝试使用以下更新：
public class Gui extends Frame {
// 创建内部类
class MyProcess {
MyProcess(String s) {
System.out.println("使用 s 进行一些操作：" + s);
}
}
public static void main(String args[]) {
new Gui();
}
...
@Override
public void mouseClicked(MouseEvent e) {
FileDialog fd = new FileDialog(gui, "文件", FileDialog.LOAD);
fd.setVisible(true);
fe.setText(fd.getDirectory());
// 根据需要使用内部类
new MyProcess(fe.getText());
}
<br>可能的控制台输出
`使用 s 进行一些操作：D:\some_path\`
<br><br>请注意，使用内部类并不是强制的，也可以是外部类。这完全取决于您的设计。也许在未来的图形界面方面，您可以对以下内容进行一些研究：`JavaFx`、`Swing`，甚至是 `Eclipse Graphics Library`。`Awt` 库是最古老的库之一。

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());
}

答案2

得分: 0

你应该将对类的引用放在构造函数之外，例如文本：

public class Gui extends Frame {
    // 你的引用
    private TextField text;
    Gui() {
        // 现在实例化你的文本框
        text = new TextField();
    }
    // 返回你的文本框的getter方法
    public TextField getTextField() {
        return text;
    }
}

然后你可以从你的界面获取文本：

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

我建议你先学习Java编程的基础，然后为自己设定更大的项目。

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;
}
}

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