java中偶尔会出现需要将一张小图片嵌入大图中或带二维码的海报图片，那么本文就是奔着这个目的来的，直接上腊肉！
zxing是生成1D和2D条形或二维码的工具类库，java图形库Graphics2D进行图片的合成。
依赖：
<dependency>
<groupId>com.google.zxing</groupId>
<artifactId>core</artifactId>
<version>3.3.3</version>
</dependency>
代码：
以下为合成图片和二维码，合成2张图片参看第一个方法注释掉的代码
/*
* overlapImage
* @description：合成二维码和图片为文件
* @author 李阳
* @date 2018/12/13
* @params [backPicPath, code]
* @return void
*/
public static final void combineCodeAndPicToFile(String backPicPath, BufferedImage code/*String fillPicPath*/) {
try {
BufferedImage big = ImageIO.read(new File(backPicPath));
BufferedImage small = code;
/*//合成两个文件时使用
BufferedImage small = ImageIO.read(new File(fillPicPath));*/
Graphics2D g = big.createGraphics();
//二维码或小图在大图的左上角坐标
int x = (big.getWidth() - small.getWidth()) / 2;
// int y = (big.getHeight() - small.getHeight()) / 2;
int y = (big.getHeight() - small.getHeight() - 100);
g.drawImage(small, x, y, small.getWidth(), small.getHeight(), null);
g.dispose();
//为了保证大图背景不变色，formatName必须为"png"
ImageIO.write(big, "png", new File("C:/Users/kevin/Desktop/combinePic.jpg"));
} catch (Exception e) {
e.printStackTrace();
}
}
/*
* combineCodeAndPicToInputstream
* @description：合成二维码和图片为输出流，可用于下载或直接展示
* @author 李阳
* @date 2018/12/13
* @params [backPicPath, code]
* @return java.io.InputStream
*/
public static final void combineCodeAndPicToInputstream(String backPicPath, BufferedImage code, HttpServletResponse resp) {
try {
BufferedImage big = ImageIO.read(new File(backPicPath));
// BufferedImage small = ImageIO.read(new File(fillPicPath));
BufferedImage small = code;
Graphics2D g = big.createGraphics();
//二维码或小图在大图的左上角坐标
int x = (big.getWidth() - small.getWidth()) / 2;
int y = (big.getHeight() - small.getHeight() - 100); //二维码距大图下边距100
g.drawImage(small, x, y, small.getWidth(), small.getHeight(), null);
g.dispose();
resp.addHeader("Content-Disposition", "attachment;filename="+ URLEncoder.encode("lia阿里.png","UTF-8") );//去掉这行设置header的代码，前端访问可以直接展示
//为了保证大图背景不变色，formatName必须为"png"
ImageIO.write(big, "png", resp.getOutputStream());
} catch (Exception e) {
e.printStackTrace();
}
}
/*
* combineCodeAndPicToBase64
* @description：合成二维码和图片为Base64，同样可用于直接展示
* @author 李阳
* @date 2018/12/14
* @params [backPicPath, code]
* @return java.lang.String
*/
public static final String combineCodeAndPicToBase64(String backPicPath, BufferedImage code) {
ImageOutputStream imOut = null;
try {
BufferedImage big = ImageIO.read(new File(backPicPath));
// BufferedImage small = ImageIO.read(new File(fillPicPath));
BufferedImage small = code;
Graphics2D g = big.createGraphics();
//二维码或小图在大图的左上角坐标
int x = (big.getWidth() - small.getWidth()) / 2;
int y = (big.getHeight() - small.getHeight() - 100);
g.drawImage(small, x, y, small.getWidth(), small.getHeight(), null);
g.dispose();
//为了保证大图背景不变色，formatName必须为"png"
ByteArrayOutputStream bs = new ByteArrayOutputStream();
imOut = ImageIO.createImageOutputStream(bs);
ImageIO.write(big, "png", imOut);
InputStream in = new ByteArrayInputStream(bs.toByteArray());
byte[] bytes = new byte[in.available()];
in.read(bytes);
String base64 = Base64.getEncoder().encodeToString(bytes);
System.out.println(base64);
return "data:image/jpeg;base64," + base64;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
/*
* createImage
* @description：生成二维码
* @author 李阳
* @date 2018/12/13
* @params [content 二维码内容, logoImgPath 中间logo, needCompress 是否压缩]
* @return java.awt.image.BufferedImage
*/
private static BufferedImage createImage(String content, String logoImgPath, boolean needCompress) throws IOException, WriterException {
Hashtable<EncodeHintType, Object> hints = new Hashtable<EncodeHintType, Object>();
hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
hints.put(EncodeHintType.CHARACTER_SET, CHARSET);
hints.put(EncodeHintType.MARGIN, 1);
//200是定义的二维码或小图片的大小
BitMatrix bitMatrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, 200, 200, hints);
int width = bitMatrix.getWidth();
int height = bitMatrix.getHeight();
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
//循环遍历每一个像素点
for (int x = 0; x < width; x++) {
for (int y = 0; y < height; y++) {
image.setRGB(x, y, bitMatrix.get(x, y) ? 0xFF000000 : 0xFFFFFFFF);
}
}
// 没有logo
if (logoImgPath == null || "".equals(logoImgPath)) {
return image;
}
// 插入logo
insertImage(image, logoImgPath, needCompress);
return image;
}
/*
* insertImage
* @description：二维码插入logo
* @author 李阳
* @date 2018/12/13
* @params [source, logoImgPath, needCompress]
* @return void
*/
private static void insertImage(BufferedImage source, String logoImgPath, boolean needCompress) throws IOException {
File file = new File(logoImgPath);
if (!file.exists()) {
return;
}
Image src = ImageIO.read(new File(logoImgPath));
int width = src.getWidth(null);
int height = src.getHeight(null);
//处理logo
if (needCompress) {
if (width > WIDTH) {
width = WIDTH;
}
if (height > HEIGHT) {
height = HEIGHT;
}
Image image = src.getScaledInstance(width, height, Image.SCALE_SMOOTH);
BufferedImage tag = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
Graphics gMaker = tag.getGraphics();
gMaker.drawImage(image, 0, 0, null); // 绘制缩小后的图
gMaker.dispose();
src = image;
}
// 在中心位置插入logo
Graphics2D graph = source.createGraphics();
int x = (200 - width) / 2;
int y = (200 - height) / 2;
graph.drawImage(src, x, y, width, height, null);
Shape shape = new RoundRectangle2D.Float(x, y, width, width, 6, 6);
graph.setStroke(new BasicStroke(3f));
graph.draw(shape);
graph.dispose();
}
public static final void main(String[] args) throws IOException, WriterException {
BufferedImage code = createImage("https://my.oschina.net/kevin2kelly", null, false);
combineCodeAndPicToFile("C:/Users/kevin/Desktop/无标题.png", code);
combineCodeAndPicToBase64("C:/Users/kevin/Desktop/无标题.png", code);
}
填充图片:
背景图和合成图片：
图一为原始背景图，第二图为base64在浏览器访问效果，三为2张图合成，四图为图片和二维码合成。
参考：
http://www.zhaochengquan.com/2018/03/29/%E5%9F%BA%E4%BA%8EZXing%E7%9A%84%E4%BA%8C%E7%BB%B4%E7%A0%81%E8%87%AA%E5%8A%A8%E7%94%9F%E6%88%90%E4%B8%8E%E5%9B%BE%E7%89%87%E5%90%88%E6%88%90/
https://blog.csdn.net/qq_35971258/article/details/80593500
来源：oschina
链接：https://my.oschina.net/u/2757387/blog/2988459