java生成二维码图片

使用zxing工具类生成

1、引入zxing的pom

<dependency>
<groupId>com.google.zxing</groupId>
<artifactId>core</artifactId>
<version>2.2</version>
</dependency>
<dependency>
<groupId>com.google.zxing</groupId>
<artifactId>javase</artifactId>
<version>2.2</version>
</dependency>
刚开始使用的3.0.0版本报错Unsupported major.minor version 51.0

原因是3.0.0版本需要jdk1.7+的支持，所以我使用的zxing的2.2版本

2、贴java代码

Map<EncodeHintType, Object> hints = new HashMap<EncodeHintType, Object>();
hints.put(EncodeHintType.MARGIN, 0);
// 指定纠错等级
hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.L);
// 指定编码格式
hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
BitMatrix bitMatrix = new MultiFormatWriter().encode("http://www.baidu.com", BarcodeFormat.QR_CODE, 256, 256, hints);

//去白边
int[] rec = bitMatrix.getEnclosingRectangle();
int resWidth = rec[2] + 1;
int resHeight = rec[3] + 1;
BitMatrix resMatrix = new BitMatrix(resWidth, resHeight);
resMatrix.clear();
for (int i = 0; i < resWidth; i++) {
for (int j = 0; j < resHeight; j++) {
if (bitMatrix.get(i + rec[0], j + rec[1])) {
resMatrix.set(i, j);
}
}
}

int width = resMatrix.getWidth();
int height = resMatrix.getHeight();
BufferedImage image = new BufferedImage(width, height,BufferedImage.TYPE_INT_ARGB);
for (int x = 0; x < width; x++) {
for (int y = 0; y < height; y++) {
image.setRGB(x, y, resMatrix.get(x, y) == true ?
Color.BLACK.getRGB():Color.WHITE.getRGB());
}
}

ImageIO.write(image,"png", new File("tmp.png"));