String text = "123456789101"; 

int width  = 300;
int height = 100; 
String imgFormat = "png";

BitMatrix bitMatrix = new UPCAWriter().encode(text, BarcodeFormat.UPC_A, width, height);
MatrixToImageWriter.writeToStream(bitMatrix, imgFormat, new FileOutputStream(new    File("C:\\code_.png")));

	public static OutputStream generate(String value) throws Exception {
		ByteArrayOutputStream bos = new ByteArrayOutputStream();
		
		BitMatrix bitMatrix = new Code128Writer().encode(value, BarcodeFormat.CODE_128, 100, 50);   // (code, BarcodeFormat.CODE_128, 300, 100);
		MatrixToImageWriter.writeToStream(bitMatrix, "bmp", bos);
		
		ByteArrayInputStream  bis =  new ByteArrayInputStream(bos.toByteArray());
		
		bos.close();
		
		BufferedImage image =  ImageIO.read(bis);
		
		Graphics g = image.getGraphics();
		
		//g.setFont(new Font("arial", 0, 8));
		g.setFont(g.getFont().deriveFont(30f));
		g.drawString("0000000", 0, 0);
		g.dispose();
		
		ImageIO.write(image, "bmp", bos);
		
		return bos;
	}