微信-商城商品的图文/商品链接分享(后台数据合成图片+二维码生成)

 private BufferedImage image;
    private int imageWidth = 750;  //图片的宽度
    private int imageHeight = 1350; //图片的高度
    @Override
    public String queryFindEntityGoodPictureDetail(Long id, Long groupId, Long memberId, String url) throws Exception {

        int H_title = 300;     //头部高度
        int H_activity = 430;  //活动高度
        int H_mainPic = 700;   //广告高度
        int H_tip = 300;       //商品价格栏
        int tip_2_top = (H_title+H_mainPic);

        MallEntityGood mallEntityGood=mallEntityGoodMapper.queryFindEntityGoodPictureDetail(id,groupId);
        image = new BufferedImage(imageWidth, imageHeight, BufferedImage.TYPE_INT_RGB);
        //设置图片的背景色
        Graphics2D main = image.createGraphics();
        main.setColor(Color.white);
        main.fillRect(0, 0, imageWidth, imageHeight);
        //***********************页面头部
        Graphics title = image.createGraphics();
        title.setColor(Color.BLACK);
        // 设置字体
        Font titleFont = new Font("宋体", Font.BOLD, 52);
        title.setFont(titleFont);
        // 如果商品名大于12个字符,截取12个字符在第一行中显示,剩余的在第二行显示
        // 完成之后优化 考虑用户在使用英文的前提下 每行字数乘两倍
        if(mallEntityGood.getName().length()>14) {
            String goodName1=mallEntityGood.getName().substring(0,14);
            if(mallEntityGood.getName().length()>14 && mallEntityGood.getName().length()<27){
                String goodName2=mallEntityGood.getName().substring(14);
                title.drawString(URLDecoder.decode(goodName2, "UTF-8"), 20, (H_title)/3+80);
            }else if(mallEntityGood.getName().length()>27){
                String goodName2=mallEntityGood.getName().substring(14,27);
                title.drawString(URLDecoder.decode(goodName2, "UTF-8")+"...", 20, (H_title)/3+80);
            }
            title.drawString(URLDecoder.decode(goodName1, "UTF-8"), 20, (H_title)/3+5);
        }else {
            title.drawString(URLDecoder.decode(mallEntityGood.getName(), "UTF-8"), 20, (H_title)/3+5);
        }

        // 获取商品所参加的活动
        // 标题之下(商品所属活动)
        Graphics activity = image.createGraphics();
        activity.setColor(Color.red);
        Font activityFont = new Font("宋体", Font.BOLD, 38);
        activity.setFont(activityFont);
        String goodid=String.valueOf(id);
        List<ActivityUnroutine> activityUnroutineList = activityUnroutineMapper.queryActivityListById(goodid);
        if(activityUnroutineList != null){
                for (int i=0;i<activityUnroutineList.size();i++){
                    if (StringUtils.isNotEmpty(activityUnroutineList.get(i).getActivityName())){
                        String activityNames= activityUnroutineList.get(i).getActivityName();
                        if (activityNames.length()>20){
                            activity.drawString( "活动:"+URLDecoder.decode(activityNames, "UTF-8").substring(0,21)+"...", 20, (H_activity)/2);
                        }else {
                            activity.drawString( "活动:"+URLDecoder.decode(activityNames, "UTF-8"), 20, (H_activity)/2);
                        }
                        break;
                    }
                }
        }else{
            String activityName="";
            activity.drawString( activityName, 20, (H_activity)/2);
        }

        //***********************插入中间广告图
        Graphics mainPic = image.getGraphics();
        BufferedImage bimg = null;
        // 获取商品图片
        if(mallEntityGood.getPicture()!=null) {
            String[] picture = mallEntityGood.getPicture().trim().split(",");
            for(int i=0;i<picture.length;i++) {
                if(picture[i].trim().length()>0){
                    bimg=ImageIO.read(new URL(picture[i]).openStream());
                    mainPic.drawImage(bimg, 0, H_title, imageWidth, H_mainPic, null);
                    mainPic.dispose();
                    break;
                }
            }
        }
        // 价格以及小图标的排布
        Graphics2D tip = image.createGraphics();
        tip.setColor(Color.red);
        Font tipFont = new Font("宋体", Font.BOLD, 52);
        tip.setFont(tipFont);
        DecimalFormat df = new DecimalFormat(".00");
        tip.drawString("¥"+ df.format(mallEntityGood.getPromotionPrice()/100), 300, tip_2_top+(H_tip)/2-40);

        Font btnFont = new Font("宋体", Font.PLAIN, 26);
        Graphics2D btn1 = image.createGraphics();
        btn1.setColor(Color.red);
        btn1.setFont(btnFont);

        Graphics mainPic3 = image.getGraphics();
        BufferedImage bimg3 = null;

        String imgurl3="http://ebank007.oss-cn-hangzhou.aliyuncs.com/20180731173813D9PJ9Q.jpg";
        bimg3=ImageIO.read(new URL(imgurl3).openStream());
        int width = bimg3.getWidth();
        int height = bimg3.getHeight();
        mainPic3.drawImage(bimg3, 580, tip_2_top+(H_tip)/2-80, width, height, null);
        mainPic3.dispose();


        Font btnFont2 = new Font("宋体", Font.PLAIN, 36);
        Graphics2D btn2 = image.createGraphics();
        btn2.setColor(Color.black);
        btn2.setFont(btnFont2);
        String salePrice="原价";
        btn2.drawString(URLDecoder.decode(salePrice, "UTF-8")+": ¥"+df.format(mallEntityGood.getSalePrice()/100), 300, tip_2_top+(H_tip)/2+30);
        btn2.drawString("------------", 300, tip_2_top+(H_tip)/2+30);
        // 确定二维码所在的位置
        Graphics2D tip1 = image.createGraphics();
        tip1.setColor(Color.black);
        Font tipFont2 = new Font("宋体", Font.PLAIN, 28);
        tip1.setFont(tipFont2);
        String ccLog="长按识别二维码";
        tip1.drawString("["+URLDecoder.decode(ccLog, "UTF-8")+"]", 35, tip_2_top+(H_tip)/2+180);
        //  用户分享链接二维码
        String shareGoodQRcode=url+"/api/oAuth2/goodDetailShare?gid="+id+"&"+"memberid="+memberId+"&"+"groupId="+groupId;
        int qrcode_height=250;
        int qrcode_width=250;
        BufferedImage image = createImage1(shareGoodQRcode, qrcode_width, qrcode_height);
        //  确定二维码在图中的位置
        Graphics mainPic1 = this.image.getGraphics();
        if(image!=null){
            mainPic1.drawImage(image, 20, tip_2_top+30, qrcode_width, qrcode_height, null);
            mainPic1.dispose();
        }
        String  uuid = UUID.randomUUID().toString();
        createImage(uuid+".png");
        //   内存中文件存储的文件夹的位置
     /* File dir=new File(uuid+".png");
        File[] lst=dir.listFiles();
        for (File f:lst){
            // 三天自动清除文件(失效处理)
            if (new Date().getTime()-f.lastModified()>24*60*60*1000*3){
                f.delete();
            }
        }*/
        File dir=new File(uuid+".png");
        if (new Date().getTime()-dir.lastModified()>24*60*60*1000*3){
            dir.delete();
        }
        InputStream in = null;
        byte[] data = null;
        //读取图片字节数组
        try {
            in = new FileInputStream(uuid+".png");
            data = new byte[in.available()];
            in.read(data);
            in.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        //对字节数组Base64编码
        BASE64Encoder encoder = new BASE64Encoder();
        return encoder.encode(data); //返回Base64编码过的字节数组字符串
//        FileImageInputStream   input = new FileImageInputStream(new File("1.png"));
//        ByteArrayOutputStream output = new ByteArrayOutputStream();
//        byte[] buf = new byte[1024];
//        int numBytesRead = 0;
//        while ((numBytesRead = input.read(buf)) != -1) {
//            output.write(buf, 0, numBytesRead);
//        }
//        byte[] data = output.toByteArray();
//        output.close();
//        input.close();
//        return data;
    }

    /**
     * 二维码图片的生成
     * @param content        链接
     * @param qrcode_width    二维码宽
     * @param qrcode_height       二维码高
     * @return
     * @throws Exception
     */
    public static BufferedImage createImage1(String content, int qrcode_width, int qrcode_height) throws Exception {
        Hashtable<EncodeHintType, Object> hints = new Hashtable<EncodeHintType, Object>();
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
        hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
        hints.put(EncodeHintType.MARGIN, 1);
        BitMatrix bitMatrix = new MultiFormatWriter().encode(content,
                BarcodeFormat.QR_CODE, qrcode_width, qrcode_height, hints);
        int width = bitMatrix.getWidth();
        int height = bitMatrix.getHeight();
        BufferedImage image = new BufferedImage(width, height,
                BufferedImage.TYPE_INT_RGB);
        for (int x = 0; x < width; x++) {
            for (int y = 0; y < height; y++) {
                image.setRGB(x, y, bitMatrix.get(x, y) ? 0xFF000000
                        : 0xFFFFFFFF);
            }
        }
        return image;
    }
    //生成图片文件
    @SuppressWarnings("restriction")
    public void createImage(String fileLocation) {
        BufferedOutputStream bos = null;
        if(image != null) {
            try {
                FileOutputStream fos = new FileOutputStream(fileLocation);
                bos = new BufferedOutputStream(fos);
                JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(bos);
                encoder.encode(image);
                fos.close();
                bos.close();
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                if (bos != null) {//关闭输出流
                    try {
                        bos.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
        }
    }

需要注意的是:后台数据合成的图片后  返回Base64 String时 前端微信显示会出现中文乱码 
　　　　　　 这一点是因为,开发时window本地下,系统中含有宋体.楷体等资源,而在服务器上
　　　　　　 是没有这些字体的需要导入TTF相匹配的肢体文件,之后重启nginx中tomcat.
   还有一点:后台代码中调用方法生成的图片,并不是保存到本地,还是服务器内存需要定时清除