function drawAndShareImage(){
  var canvas = document.createElement("canvas");
  canvas.width = 700;
  canvas.height = 700;
  var context = canvas.getContext("2d");
  context.rect(0 , 0 , canvas.width , canvas.height);
  context.fillStyle = "#fff";
  context.fill();
  var myImage = new Image();
  myImage.src = "./2.png";  //背景图片 你自己本地的图片或者在线图片
  myImage.crossOrigin = 'Anonymous';
  myImage.onload = function(){
    context.drawImage(myImage , 0 , 0 , 700 , 700);
    context.font = "60px Courier New";
    context.fillText("我是文字",350,450);
    var myImage2 = new Image();
    myImage2.src = "./1.png";  //你自己本地的图片或者在线图片
    myImage2.crossOrigin = 'Anonymous';
    myImage2.onload = function(){
      context.drawImage(myImage2 , 175 , 175 , 225 , 225);
      var base64 = canvas.toDataURL("image/png"); //"image/png" 这里注意一下
      var img = document.getElementById('avatar');
      // document.getElementById('avatar').src = base64;
      img.setAttribute('src' , base64);
    }
  }
}

public static String generateCode(String codeUrl, Integer userId, String userName) {
 Font font = new Font("微软雅黑", Font.PLAIN, 30);// 添加字体的属性设置
 String projectUrl = PathKit.getWebRootPath() + "/before/codeImg/";
 String imgName = projectUrl + userId + ".png";
 try {
 // 加载本地图片
 String imageLocalUrl = projectUrl + "weixincode2.png";
 BufferedImage imageLocal = ImageIO.read(new File(imageLocalUrl));
 // 加载用户的二维码
 BufferedImage imageCode = ImageIO.read(new URL(codeUrl));
 // 以本地图片为模板
 Graphics2D g = imageLocal.createGraphics();
 // 在模板上添加用户二维码(地址,左边距,上边距,图片宽度,图片高度,未知)
 g.drawImage(imageCode, 575, imageLocal.getHeight() - 500, 350, 350, null);
 // 设置文本样式
 g.setFont(font);
 g.setColor(Color.BLACK);
 // 截取用户名称的最后一个字符
 String lastChar = userName.substring(userName.length() - 1);
 // 拼接新的用户名称
 String newUserName = userName.substring(0, 1) + "**" + lastChar + " 的邀请二维码";
 // 添加用户名称
 g.drawString(newUserName, 620, imageLocal.getHeight() - 530);
 // 完成模板修改
 g.dispose();
 // 获取新文件的地址
 File outputfile = new File(imgName);
 // 生成新的合成过的用户二维码并写入新图片
 ImageIO.write(imageLocal, "png", outputfile);
 } catch (Exception e) {
 e.printStackTrace();
 }
 // 返回给页面的图片地址(因为绝对路径无法访问)
 imgName = Constants.PROJECT_URL + "codeImg/" + userId + ".png";
 return imgName;
}