在图片模板上面画二维码及文字常用到的几个方法

（1）加载自定义的ttf字体

  	import java.awt.Font;
    Font demiFont = Font.createFont(Font.TRUETYPE_FONT, new File("字体的路径"));

（2）加载图片模板

   import java.awt.Graphics2D;
   File typeAFile = new File(“模板图片的路径”);
   BufferedImage bgImage = ImageIO.read(typeAFile);

（3）获得Graphics2D

 Graphics2D graphics2D = bgImage.createGraphics();
 AlphaComposite ac = AlphaComposite.getInstance(AlphaComposite.SRC_OVER);
 graphics2D.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
 graphics2D.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_GASP);
 graphics2D.setComposite(ac);
 graphics2D.setBackground(Color.WHITE);
 // 画图片
 graphics2D.drawImage(BufferedImage codeImage, x, y, width, height, null);
 // 创建指定大小的字体
 Font accountHolderNameFont= demiFont.deriveFont(Font.BOLD, 80);
 graphics2D.setFont(accountHolderNameFont);
 graphics2D.setColor(new Color(109, 110, 112));
 graphics2D.drawString("要画字符串",x,y);
    //下面是一个很重要的方法,可以获取指定字体大小的字符串的像素宽度
import sun.font.FontDesignMetrics;
FontDesignMetrics.getMetrics(accountHolderNameFont).stringWidth(“字符串”));