问JFrame:获得无边框的尺寸？

EN

frame.pack();
System.out.println("frame width : "+getWidth());
System.out.println("frame height: "+getHeight());
System.out.println("content pane width : "+getContentPane().getWidth());
System.out.println("content pane height: "+getContentPane().getHeight());
System.out.println("width  of left + right  borders: "+(getWidth()-getContentPane ().getWidth()));
System.out.println("height of top  + bottom borders: "+(getHeight()-getContentPane().getHeight()));

frame.getContentPane().getSize();

Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();

pack(); // Need this, otherwise insets() show as 0.  
int scrW = (int)screenSize.getWidth();
int scrH = (int)screenSize.getHeight();
  int innerW = scrW - getInsets().left - getInsets().right;
  int innerH = scrH - getInsets().top - getInsets().bottom;

  // Need to setSize(), otherwise pack() will collapse the empty JFrame
  setSize(scrW, scrH);

public static Dimension getInnerSize(Frame frame) {
    Dimension size = frame.getSize();
    Insets insets = frame.getInsets();
    if (insets != null) {
        size.height -= insets.top + insets.bottom;
        size.width -= insets.left + insets.right;
    }
    return size;
}

private static Insets defaultInsets;
public static Insets getInsetsWithDefault(Frame frame) {
    // insets only correct after pack() and setVisible(true) has been
    // called, so we use some fallback strategies
    Insets insets = frame.getInsets();
    if (insets.top == 0) {
        insets = defaultInsets;
        if (insets == null) {
            insets = new Insets(26, 3, 3, 3);
            // usual values for windows as our last resort
            // but only as long as we never saw any real insets
        }
    } else if (defaultInsets == null) {
        defaultInsets = (Insets) insets.clone();
    }
    return insets;
}

frame.addWindowListener(new WindowAdapter() {

    @Override
    public void windowOpened(WindowEvent e) {
        MyUtilClass.getInsetsWithDefault(frame); // init the defaultInsets
    }

});