版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/bcqd1211/article/details/85567000
此文章首发于 https://www.jianshu.com/p/394f9b0357b3
最近有个需求，需要App实现群头像仿微信九宫格排列，由于让客户端生成头像显示会比较慢，因此只能用服务端实现这个需求,但是网上找都不是很符合要求，于是自己动手改了下实现了该功能:
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
* @param dir 输出路径
* @param groupId 群编号
* @return
* @throws IOException
*/
public static boolean getCombinationOfhead(List<String> paths, String dir, String groupId)
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;
}
}
StringBuffer outPath = new StringBuffer().append(dir)
.append(File.separatorChar)
.append("GP-" + groupId).append(".jpg");
String format = "JPG";
File file = new File(outPath.toString());
if (!file.exists()) {
file.mkdirs();
}
return ImageIO.write(outImage, format, file);
}
/**
* 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
// System.out.println("图片缩放"+filePath);
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;
}
/**
* 删除文件
* @param path
* @param filename
*/
public void delFile(String path, String filename) {
File file = new File(path + "/" + filename);
if (file.exists() && file.isFile()) {
file.delete();
}
}
/**
* 可依次生成九种情况的群头像
*
* @param args
* @throws IOException
*/
public static void main(String[] args) throws IOException {
Integer groupId = 0;
for (int i = 1; i < 10; i++) {
List<String> list = new ArrayList<>();
for (int j = 0; j < i; j++) {
//本地图片路径或者网络图片路径
list.add("/Users/Basil/Desktop/1.jpg");
}
File file = new File("");
//生成目录
String path = file.getCanonicalPath() + "/src/main/webapp/temp/";
groupId++;
ImageUtil.getCombinationOfhead(list, path, groupId.toString());
}
}
生成的效果图：
详细效果图：
