java 图片格式转换（png&jpg） & 截图

png to jpg主要功能代码：

				BufferedImage bufferedImage;
				try {
					bufferedImage=ImageIO.read(new File("C:\\Users\\lenovo\\Desktop\\Download\\z.png"));
					BufferedImage newBufferedImage =new BufferedImage(bufferedImage.getWidth(),bufferedImage.getHeight(), BufferedImage.TYPE_INT_RGB);
					newBufferedImage .createGraphics().drawImage(bufferedImage,0,0,Color.white,null);
					
					ImageIO.write(newBufferedImage,"jpg",new File("C:\\Users\\lenovo\\Desktop\\Download\\z.jpg")  );
					
					JOptionPane.showMessageDialog(null,"ok");
					
				} catch (Exception e) {
					JOptionPane.showMessageDialog(null,e);
				}

jpg to png主要功能代码：

				BufferedImage bufferedImage;
				try {
					bufferedImage=ImageIO.read(new File("C:\\Users\\lenovo\\Desktop\\Download\\z.jpg"));
					BufferedImage newBufferedImage =new BufferedImage(bufferedImage.getWidth(),bufferedImage.getHeight(), BufferedImage.TYPE_INT_RGB);
					newBufferedImage .createGraphics().drawImage(bufferedImage,0,0,Color.white,null);
					
					ImageIO.write(newBufferedImage,"png",new File("C:\\Users\\lenovo\\Desktop\\Download\\z.png")  );
					
					JOptionPane.showMessageDialog(null,"ok");
					
				} catch (Exception e) {
					JOptionPane.showMessageDialog(null,e);
				}

截图功能：

				try {
					Rectangle screenRect=new Rectangle(Toolkit.getDefaultToolkit().getScreenSize());
					BufferedImage capture=new Robot().createScreenCapture(screenRect);
					ImageIcon icon=new ImageIcon(capture);
					ImageIO.write(capture, "png", new File("d:\\1.png"));
					
				} catch (Exception e) {
					JOptionPane.showMessageDialog(null, e);
				}