通过getter / setter将数据传递给其他类

Question

我在将数据从GUI传递到其他类时遇到问题。 一切都在GUI中初始化，然后从那里将数据传递到另一个类，在该类中可能进行其他更改：（用于编译的简化部分和缺失部分）

class GUI extends JFrame {
final Configuration conf = new Configuration();

GUI() {
    initComponents();
}

private void initComponents() {

    //Setup default values
    conf.expectFires(false);
    conf.expectRain(false);
    conf.expectDisaster(true);

    JComboBox<String> seasonTypes = new JComboBox<>(new String[]{"Winter", "Spring", "Summer", "Fall"});

    seasonTypes.setSelectedIndex(0);
    conf.setSeason(seasonTypes.getItemAt(seasonTypes.getSelectedIndex()));

    //Action listener for dynamic changes to whatever is selected
    seasonTypes.addActionListener(e -> {
        String season = seasonTypes.getSelectedItem().toString();
        if (!season.equals(""))
            conf.setSeason(season);
    });

    pack();
    setLocationRelativeTo(getOwner());
    setVisible(true);
}
}

数据应该保存到我的配置类（getter / setter类）中。 我无法检索任何数据，除非我在同一类中进行了设置：

主班：

public class Main {

public static void main(String[] args) {
    Configuration conf = new Configuration();

    //code for GUI not included but pretend the GUI is called here

    //data does not come out it's basically unset.
    System.out.println("Data from GUI: [season]"+ conf.getSeason()+ " Season expectations: " + conf.expectations());

    //yet this works just fine. 
    conf.setSeason("Summer");
    System.out.println("What's the last season set?: " + conf.getSeason()); 
}
}

Answer 1

看起来您正在创建Configuration类的两个实例。 一个在GUI ，一个在您的Main类中。 这些不是共享的。

如果要从GUI使用Configuration ，请尝试在GUI类中为Configuration添加吸气剂

public Configutation getConfig()
{
     return conf;
}

然后在您的主要尝试中：

public class Main {

    public static void main(String[] args) {
    //code for GUI not included but pretend the GUI is called here
    // Assuming something like:
    GUI gui = new GUI();

    Configuration conf = gui.getConfig();

    System.out.println("Data from GUI: [season]"+ conf.getSeason()+ " Season expectations: " + conf.expectations());
    }
}

另一种选择是将Configuration创建为单例-然后您获得相同的实例，而不是每次实例化一个新实例。 这是如何执行此操作的示例