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.csdn.net/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：
