jPanel Transparan

Create java class

example : JpanelTransparan.java

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JPanel;

public class jPanelTransparan extends JPanel{
  private Color col;

    public jPanelTransparan() {
        setOpaque(false);
        col=new Color(0,0,0,100);//warna hitam transparan dengan opacity 100
    }

    @Override
    public void setBackground(Color bg) {
        super.setBackground(bg);
        col=new Color(0,0,0,100);//warna hitam transparan dengan opacity 100
        repaint();
    }

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D gr=(Graphics2D)g.create();
        gr.setColor(col);
        gr.fillRoundRect(0, 0, getWidth(), getHeight(), 0, 0);
        gr.dispose();
    }

}

Clean and Build

Right click java project, select clean and build

How to Use

• Create Jframe 
• Drag and drop JpanelTransparan.java into jframe