FastDFS+java九宫格微信群聊头像

参考的工具类出自博客：https://www.jianshu.com/p/394f9b0357b3

我仅仅只是改了下：通过getCombinationOfhead方法返回的是 byte[] 字节数组，其它不变。（因为我要将图片上传到 FastDFS，然后通过FastDFS返回 url 链接）

public final class ImageUtil {

    /**
     * 图片的间隙
     */
    private static final int SIDE = 6;
    /**
     * 画板尺寸
     */
    private static final int CANVANS_W = 112;
    private static final int CANVANS_H = 112;

    /**
     * 尺寸1 （小）
     */
    private static final int ONE_IMAGE_SIZE = CANVANS_H - (2 * SIDE);
    /**
     * 尺寸2 （中）
     */
    private static final int TWO_IMAGE_SIZE = (CANVANS_H - (3 * SIDE)) / 2;
    /**
     * 尺寸3 （大）
     */
    private static final int FIVE_IMAGE_SIZE = (CANVANS_H - (4 * SIDE)) / 3;

    private ImageUtil() {
    }

    /**
     * 生成群组头像
     *
     * @param paths   图片链接
     * @return
     * @throws IOException
     */
    public static byte[] getCombinationOfhead(List<String> paths)
            throws IOException {
        List<BufferedImage> bufferedImages = new ArrayList<BufferedImage>();

        int imageSize = 0;
        if (paths.size() <= 1) {
            //若为一张图片
            imageSize = ONE_IMAGE_SIZE;
        } else if (paths.size() > 1 && paths.size() < 5) {
            //若为2-4张图片

            imageSize = TWO_IMAGE_SIZE;
        } else {
            //若>=5张图片
            imageSize = FIVE_IMAGE_SIZE;
        }

        for (int i = 0; i < paths.size(); i++) {
            BufferedImage resize2 = ImageUtil.resize2(paths.get(i), imageSize, imageSize, true);
            bufferedImages.add(resize2);
        }

        BufferedImage outImage = new BufferedImage(CANVANS_W, CANVANS_H, BufferedImage.TYPE_INT_RGB);

        // 生成画布
        Graphics g = outImage.getGraphics();

        Graphics2D g2d = (Graphics2D) g;

        // 设置背景色
        g2d.setBackground(new Color(231, 231, 231));

        // 通过使用当前绘图表面的背景色进行填充来清除指定的矩形。
        g2d.clearRect(0, 0, CANVANS_W, CANVANS_H);

        // 开始拼凑 根据图片的数量判断该生成那种样式的组合头像目前为九种

        for (int i = 1; i <= bufferedImages.size(); i++) {
            Integer size = bufferedImages.size();
            switch (size) {
                case 1:
                    g2d.drawImage(bufferedImages.get(i - 1), SIDE, SIDE, null);
                    break;
                case 2:
                    if (i == 1) {
                        g2d.drawImage(bufferedImages.get(i - 1), SIDE, (CANVANS_W - imageSize) / 2, null);
                    } else {
                        g2d.drawImage(bufferedImages.get(i - 1), 2 * SIDE + imageSize, (CANVANS_W - imageSize) / 2, null);
                    }
                    break;
                case 3:
                    if (i == 1) {
                        g2d.drawImage(bufferedImages.get(i - 1), (CANVANS_W - imageSize) / 2, SIDE, null);
                    } else {
                        g2d.drawImage(bufferedImages.get(i - 1), (i - 1) * SIDE + (i - 2) * imageSize, imageSize + (2 * SIDE), null);

                    }
                    break;
                case 4:

                    if (i <= 2) {
                        g2d.drawImage(bufferedImages.get(i - 1), i * SIDE + (i - 1) * imageSize, SIDE, null);

                    } else {
                        g2d.drawImage(bufferedImages.get(i - 1), (i - 2) * SIDE + (i - 3) * imageSize, imageSize + 2 * SIDE, null);

                    }
                    break;
                case 5:
                    if (i <= 2) {
                        g2d.drawImage(bufferedImages.get(i - 1), (CANVANS_W - 2 * imageSize - SIDE) / 2 + (i - 1) * imageSize + (i - 1) * SIDE, (CANVANS_W - 2 * imageSize - SIDE) / 2, null);

                    } else {
                        g2d.drawImage(bufferedImages.get(i - 1), (i - 2) * SIDE + (i - 3) * imageSize, ((CANVANS_W - 2 * imageSize - SIDE) / 2) + imageSize + SIDE, null);

                    }
//
                    break;
                case 6:
                    if (i <= 3) {
                        g2d.drawImage(bufferedImages.get(i - 1), SIDE * i + imageSize * (i - 1), (CANVANS_W - 2 * imageSize - SIDE) / 2, null);
                    } else {
                        g2d.drawImage(bufferedImages.get(i - 1), ((i - 3) * SIDE) + ((i - 4) * imageSize), ((CANVANS_W - 2 * imageSize - SIDE) / 2) + imageSize + SIDE, null);
                    }
                    break;
                case 7:
                    if (i <= 1) {
                        g2d.drawImage(bufferedImages.get(i - 1), 2 * SIDE + imageSize, SIDE, null);
                    }
                    if (i <= 4 && i > 1) {
                        g2d.drawImage(bufferedImages.get(i - 1), ((i - 1) * SIDE) + ((i - 2) * imageSize), 2 * SIDE + imageSize, null);
                    }
                    if (i <= 7 && i > 4) {
                        g2d.drawImage(bufferedImages.get(i - 1), ((i - 4) * SIDE) + ((i - 5) * imageSize), 3 * SIDE + 2 * imageSize, null);
                    }
                    break;
                case 8:
                    if (i <= 2) {
                        g2d.drawImage(bufferedImages.get(i - 1), (CANVANS_W - 2 * imageSize - SIDE) / 2 + (i - 1) * imageSize + (i - 1) * SIDE, SIDE, null);
                    }
                    if (i <= 5 && i > 2) {
                        g2d.drawImage(bufferedImages.get(i - 1), ((i - 2) * SIDE) + ((i - 3) * imageSize), 2 * SIDE + imageSize, null);
                    }
                    if (i <= 8 && i > 5) {
                        g2d.drawImage(bufferedImages.get(i - 1), ((i - 5) * SIDE) + ((i - 6) * imageSize), 3 * SIDE + 2 * imageSize, null);
                    }
                    break;
                case 9:
                    if (i <= 3) {
                        g2d.drawImage(bufferedImages.get(i - 1), (i * SIDE) + ((i - 1) * imageSize), SIDE, null);
                    }
                    if (i <= 6 && i > 3) {
                        g2d.drawImage(bufferedImages.get(i - 1), ((i - 3) * SIDE) + ((i - 4) * imageSize), 2 * SIDE + imageSize, null);
                    }
                    if (i <= 9 && i > 6) {
                        g2d.drawImage(bufferedImages.get(i - 1), ((i - 6) * SIDE) + ((i - 7) * imageSize), 3 * SIDE + 2 * imageSize, null);
                    }
                    break;
                default:
                    break;
            }
        }

        //将BufferedImage转为byte[]字节数组
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        ImageIO.write(outImage, "jpg", baos );
        baos.flush();
        byte[] imageInByte = baos.toByteArray();
        baos.close();
        return imageInByte;
    }

    /**
     * 图片缩放
     *
     * @param filePath 图片路径
     * @param height   高度
     * @param width    宽度
     * @param bb       比例不对时是否需要补白
     */
    public static BufferedImage resize2(String filePath, int height, int width,
                                        boolean bb) {
        try {
            double ratio = 0; // 缩放比例
            BufferedImage bi = null;
            if (filePath.indexOf("http://") == 0) {
                bi = ImageIO.read(new URL(filePath));
            } else {
                bi = ImageIO.read(new File(filePath));
            }
            Image itemp = bi.getScaledInstance(width, height,
                    Image.SCALE_SMOOTH);
            // 计算比例
            if ((bi.getHeight() > height) || (bi.getWidth() > width)) {
                if (bi.getHeight() > bi.getWidth()) {
                    ratio = (new Integer(height)).doubleValue() / bi.getHeight();
                } else {
                    ratio = (new Integer(width)).doubleValue() / bi.getWidth();
                }
                AffineTransformOp op = new AffineTransformOp(
                        AffineTransform.getScaleInstance(ratio, ratio), null);
                itemp = op.filter(bi, null);
            }
            if (bb) {
                BufferedImage image = new BufferedImage(width, height,
                        BufferedImage.TYPE_INT_RGB);
                Graphics2D g = image.createGraphics();
                g.setColor(Color.white);
                g.fillRect(0, 0, width, height);
                if (width == itemp.getWidth(null)) {
                    g.drawImage(itemp, 0, (height - itemp.getHeight(null)) / 2,
                            itemp.getWidth(null), itemp.getHeight(null),
                            Color.white, null);
                } else {
                    g.drawImage(itemp, (width - itemp.getWidth(null)) / 2, 0,
                            itemp.getWidth(null), itemp.getHeight(null),
                            Color.white, null);
                }
                g.dispose();
                itemp = image;
            }
            return (BufferedImage) itemp;
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

}

关于FastDFS与SpringBoot的配置可以看该博文：https://blog.youkuaiyun.com/xyang81/article/details/52850667

使用的FastDFS版本：

<dependency>
	<groupId>com.github.tobato</groupId>
	<artifactId>fastdfs-client</artifactId>
	<version>1.26.2</version>
</dependency>

在FastDFSClientWrapper中 新增了一个方法：（其实只是把入参变成了 byte[]）

@Component
public class FastDFSClientWrapper {

    @Autowired
    private FastFileStorageClient storageClient;

    /**
     * 上传byte[]字节数组
     */
    public String uploadFile(byte[] buff, String fileExtension) {
        ByteArrayInputStream stream = new ByteArrayInputStream(buff);
        StorePath storePath = storageClient.uploadFile(stream,buff.length, fileExtension,null);
        return getResAccessUrl(storePath);
    }

    // 封装图片URL地址
    private String getResAccessUrl(StorePath storePath) {
        return storePath.getFullPath();
    }
}

然后就可以使用了：

@RestController
@RequestMapping("/")
public class GroupsController {
    
    @Autowired
    private FastDFSClientWrapper dfsClient;


    /**
     * @param picUrls FastDFS上的图片链接集合
     * @return 返回图片在FastDFS上的url链接
     */
    private String init9Pic(List<String> picUrls){
        try {
            //生成九宫格群组头像
            byte[] buff = ImageUtil.getCombinationOfhead(picUrls);
            //上传到FastDFS
            String url = dfsClient.uploadFile(buff,"jpg");
            if(!Objects.equals(url, "")){
                return url;
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return "";
    }
     
}

搞定：