如何将变量从一个jframe传递到另一个jframe？

public class SourceFrame extends JFrame {
    private String variable;

    public SourceFrame() {
        // ...
    }

    public void openTargetFrame() {
        TargetFrame targetFrame = new TargetFrame(variable);
        targetFrame.setVisible(true);
    }
}

public class TargetFrame extends JFrame {
    public TargetFrame(String variable) {
        // 使用传递过来的变量进行操作
    }
}

public class SourceFrame extends JFrame {
    private String variable;

    public SourceFrame() {
        // ...
    }

    public void openTargetFrame() {
        TargetFrame targetFrame = new TargetFrame();
        targetFrame.setVariable(variable);
        targetFrame.setVisible(true);
    }
}

public class TargetFrame extends JFrame {
    private String variable;

    public void setVariable(String variable) {
        this.variable = variable;
    }

    // 使用variable进行操作
}

public class SourceFrame extends JFrame {
    private static String variable;

    public SourceFrame() {
        // ...
    }

    public void openTargetFrame() {
        TargetFrame targetFrame = new TargetFrame();
        targetFrame.setVisible(true);
    }

    public static String getVariable() {
        return variable;
    }
}

public class TargetFrame extends JFrame {
    public TargetFrame() {
        String variable = SourceFrame.getVariable();
        // 使用variable进行操作
    }
}