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How to make my JFrame components dynamically scale when resizing the window, without hard-coding position and size values?

I'm learning java through university and I've been taught the basics of making a java program and designing GUIs. Maximizing a window after running my program makes all the JFrame components stay in place while grey fills the rest of the space. Here's an example of how it looks like:
JFrame window normally, Maximized window before "fix".
After failing to find a solution I came up with a band-aid solution which is to get the component locations and just move them with hard-coded values when the jframe is maximized. This was not an elegant solution and every jframe in my java course project increased in the number of elements on screen. Is there any piece of code to make my components move and resize automatically and dynamically?
Here's what I've tried so far:
First I obtained the positions of components through 2D points:
Point managementLoginBtnLocation, empLogLocation, logoLocation, customerBtnLocation, welcomeLblLocation, contactBtnLocation, aboutBtnLocation, mainMenuBtnLocation;
//Constructor and rest of code...
public final void getOriginalComponentLocations()
{
managementLoginBtnLocation = managementLoginBtn.getLocation();
empLogLocation = empLoginBtn.getLocation();
logoLocation = shopLogo.getLocation();
customerBtnLocation = customerBtn.getLocation();
welcomeLblLocation = welcomeLbl.getLocation();
contactBtnLocation = contactBtn.getLocation();
aboutBtnLocation = aboutBtn.getLocation();
mainMenuBtnLocation = mainMenuBtn.getLocation();
}
//This method is called within the constructor.
I implemented the ComponentListener Interface and added a component listener to my jframe. Then I made it so when the jframe's size changes, it changes the size of the jlabel used for background art. And if the label's width is greater than 800 (the default I used while designing) it moves the components and doubles their size and font size. When the jframe is minimized the label will go back to the default size so I made a method to revert the font sizes, because I found the component sizes and locations reset automatically.
public void componentResized(ComponentEvent e)
{
//Resizing the background label and setting its icon to a resized version of its current icon.
backgroundMainArt.setSize(this.getWidth() - 16, this.getHeight() - 21);
ImageIcon icon = new ImageIcon("C:\\Program Files\\OMOClothingStore\\Resources\\Main menu\\main menu background art.jpg");
Image img = icon.getImage();
Image newImage = img.getScaledInstance(backgroundMainArt.getWidth(), backgroundMainArt.getHeight(), Image.SCALE_FAST);
icon = new ImageIcon(newImage);
backgroundMainArt.setIcon(icon);
if(backgroundMainArt.getWidth() > 800) //When the size of the label is greater than default
{
//I move the components, enlarge the buttons and zoom the font size
moveComponents();
enlargeBtns();
zoomBtnsFontSize();
}
else //When the label is back to its original size
{
//I revert the font sizes as button sizes and positions reset automatically
revertBtnsFontSize();
setLogoIconAndBackgroundArtAndWelcomeLbl();
}
}
public void moveComponents()
{
moveLogo();
moveManagementLoginBtn();
moveEmployeeLoginBtn();
moveCustomerBtn();
moveWelcomeLbl();
moveContactInfoBtn();
moveAboutBtn();
moveMainMenuBtn();
}
public void moveLogo()
{
ImageIcon logoIcon = new ImageIcon("C:\\Program Files\\OMOClothingStore\\Resources\\Shared resources\\OMO Clothing Store logo.png");
Image logoImg = logoIcon.getImage();
Image newLogoImage = logoImg.getScaledInstance(250, 250, Image.SCALE_DEFAULT);
logoIcon = new ImageIcon(newLogoImage);
shopLogo.setIcon(logoIcon);
Point newLogoLocation = new Point();
newLogoLocation.x = (logoLocation.x * 2) + 200;
newLogoLocation.y = (logoLocation.y * 2) + 30;
shopLogo.setLocation(newLogoLocation);
}
//The rest of the "moveX" methods follow the same pattern as moveLogo()
public void enlargeBtns()
{
managementLoginBtn.setSize(410, 94);
empLoginBtn.setSize(410, 94);
customerBtn.setSize(410, 94);
}
public void zoomBtnsFontSize()
{
customerBtn.setFont(sizeBtn.getFont());
//sizeBtn is a JButton that has a font size of 24. I found that just creating a new Font object with bigger size here made the font way larger for some reason.
empLoginBtn.setFont(sizeBtn.getFont());
managementLoginBtn.setFont(sizeBtn.getFont());
}
public void revertBtnsFontSize()
{
empLoginBtn.setFont(new Font("Segoe UI", Font.PLAIN, 14));
managementLoginBtn.setFont(new Font("Segoe UI", Font.PLAIN, 14));
customerBtn.setFont(new Font("Segoe UI", Font.PLAIN, 14));
}
I split the moving of the components into many methods inside other methods because I found it easier to keep up with.
This worked. Here's how it looks like when running the JFrame: Maximized window after "fix". But moving on to other JFrames, they are more intricate and have many more components - extra buttons, panels with other components in them, menu bars, etc.
Is there a better approach to fixing this? Or do I just remove the ability to resize and move on?

Fit setIcon to JButton Array

I know this has been asked a ton of times, but I've searched everywhere and still haven't found an answer. I'm relatively new to Java. I have
JButton b[][];
Later, I assign b[3][3].setIcon(path). However, the image at path is always a small section of the actual image the size of the JButton. What I want is to re-size the image to fit the size of the JButton. Is there any way to do this? By the way, here's some code that's (I think) is important:
int n = 8;
int m = 8;
...
b = new JButton[n][m];
setLayout(new GridLayout(n,m));
for (int y = 0;y<m;y++){
for (int x = 0;x<n;x++){
b[x][y] = new JButton(" ");
b[x][y].addActionListener(this);
add(b[x][y]);
b[x][y].setEnabled(true);
}
}

What I want is to re-size the image to fit the size of the JButton.
You can use the Stretch Icon class.
It will allow you to automatically resize the Icon:
to fill the space of the button, or
keep the Icon proportion and fill the space of the button
The resizing is done dynamically so you don't need scaled images.

What you obviously need is a Icon Resizer method, something in the way of what I have provided below:
public static Icon resizeIcon(ImageIcon icon, int resizedWidth, int resizedHeight) {
Image img = icon.getImage();
Image img = img.getScaledInstance(resizedWidth, resizedHeight, java.awt.Image.SCALE_SMOOTH);
return new ImageIcon(img);
}
You can call this method after the image has already been applied to the JButton and after it has been added to whatever panel:
b[3][3].setIcon(path)
b[3][3].setIcon(resizeIcon((ImageIcon) b[3][3].getIcon(),
b[3][3].getWidth() - 15, b[3][3].getHeight() - 15));
or you could do it this way:
ImageIcon img = new ImageIcon("MyImage.png");
Icon icn = resizeIcon(img, b[3][3].getWidth() - 15, b[3][3].getHeight() - 15);
b[3][3].setIcon(icn);

setLocation on a JButton doesn't seem to work as expected

Here is my shortened version of my code:
JPanel card1 = new JPanel();
JLabel switch1 = new JLabel(new ImageIcon("switch1.jpg"));
switch1.setLocation(TOPSWITCH, LEFTSWITCH1);
JLabel switch2 = new JLabel(new ImageIcon("switch1.jpg"));
switch2.setLocation(TOPSWITCH, LEFTSWITCH2);
JLabel switch3 = new JLabel(new ImageIcon("switch1.jpg"));
switch3.setLocation(TOPSWITCH, LEFTSWITCH3);
card1.add(switch1);
card1.add(switch2);
card1.add(switch3);
card1.setBackground(Color.BLACK);
/* JButton goToRoom = new JButton("TEST");
goToRoom.setLocation(180, 270);
card1.add(goToRoom); */
card1 is added to a JFrame of sized using my_frame.setSize(400, 300);.
The above code works as expected. But when I uncomment the comment piece of code, the JButton appears to the right side of the images(JLabels) instead of appearing below the images. What could be the problem?
Additional information:
final static int TOPSWITCH = 150;
final static int LEFTSWITCH1 = 65 ;
final static int LEFTSWITCH2 = 155;
final static int LEFTSWITCH3 = 245;
switch1.jpg is of dimensions 91 x 150
Note: I want to do this without adding more JPanels.

What could be the problem?
Wanting to set explicit locations.
Fighting the layout manager.
Java GUIs have to work on different OS', screen size, screen resolution etc. using different PLAFs in different locales. As such, they are not conducive to pixel perfect layout. Instead use layout managers, or combinations of them along with layout padding and borders for white space.

Center a button or image

I'm using Eclipse to create an app for Android. I know you set attributes such as centering a button or image in the XML file but How would you do this in Java?

Its hard to say without knowing what you have. However, if you look through the docs, every xml attribute has a related method in Java. For example, Look at the View Docs and you can see a list of attributes with its corresponding Java method and a description of what it actually does. You should be able to use this to get you started then you can ask a question with code you have tried, precise problem you are having, and any error messages you might be getting. Good luck!

Use code to center your stuff, not attributes in an XML file.
Center a button:
Use a FlowLayout. This will keep the button centered horizontally in the container, but not vertically.
JButton button = new JButton("Click Me!");
panel.setLayout(new FlowLayout(FlowLayout.CENTER));
panel.add(button);
If you want it centered in both directions, you could use BoxLayout.
JButton button = new JButton("Click Me!");
button.setAlignmentX(Component.CENTER_ALIGNMENT);
panel.setLayout(new BoxLayout(panel, BoxLayout.PAGE_AXIS));
panel.add(Box.createVerticalGlue());
panel.add(button);
panel.add(Box.createVerticalGlue());
Center image:
#Override
public void paintComponent(Graphics g)
{
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
int xCenter = (this.getWidth() - image.getWidth()) / 2;
int yCenter = (this.getHeight() - image.getHeight()) / 2;
g2d.drawImage(image, xCenter, yCenter, null);
}

Have you tried :
Button button = new Button(getApplicationContext());
button.setLayoutParams(newLayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT));
button.setGravity(Gravity.CENTER_HORIZONTAL|Gravity.CENTER_VERTICAL);

Swing: resize Image but keep same size

I want to be able to do something similar to resize canvas in gimp
I want to generate a bunch of images to a certain width.
I used
int width = (int)(size * fraction);
int height =(int)(size*icon.getIconHeight()/icon.getIconWidth()*fraction);
miniature = new ImageIcon(i.getScaledInstance(width, height, Image.SCALE_SMOOTH));
this goes well while I'm doing fraction 1 but I have 3 images that have the same source but are different size (1, 2/3, 1/3)
the problem is
I have and image A
I want to create B, C and D such as the drawing inside respect the follow ratio
B = A
C = 2/3 A
D = 1/3 A
but the image stays the same dimension A = B = C = D

Assuming I'm following what you are trying to do...
Create a JLabel for each image:
JLable l = new JLabel(miniture);
Create a JLabel with a GridLayout:
JPanel p = new JPanel(new GridLayout());
Add the labels to the panel:
p.add(l);
The GridLayout will ensure that all the JLabels will have the same height and width.