在现在的网站开发中,难免会遇到要生成二维码的情况,比如要使用网页版的微信支付什么的.这里笔者分享一个java生成二维码的demo,这里使用到的是google的zxing,你可以在github上找到源码.
- 你需要引入zxing的jar包,如果是maven工程.
<dependency>
<groupId>com.google.zxing</groupId>
<artifactId>core</artifactId>
<version>3.2.1</version>
</dependency>
- 后台:在你的controller中放入以下方法,访问 YOUR-PATH/qr即可
//[测试] 二维码url
@RequestMapping("/qr")
public String testQRCode(Model model) {
//这里随便给了一个微信支付相关的url
model.addAttribute("code_url", "weixin://wxpay/bizpayurl?pr=PbcM89o");
//返回qr.html
return "qr";
}
//显示二维码图片, 这个地址配在img的src下
@RequestMapping("/qr-img")
@ResponseBody
public void getQRCode(String code_url, HttpServletResponse response) {
encodeQrcode(code_url, response);
}
//不保存二维码图片,以流的形式返回
private void encodeQrcode(String content, HttpServletResponse response) {
if (StringUtils.isEmpty(content)) return;
MultiFormatWriter multiFormatWriter = new MultiFormatWriter();
Map hints = new HashMap();
//设置字符集编码类型
hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
//设置二维码四周的白色边框 ,默认是4,默认为4的时候白色边框实在是太粗了
hints.put(EncodeHintType.MARGIN, 0);
BitMatrix bitMatrix = null;
try {
bitMatrix = multiFormatWriter.encode(content, BarcodeFormat.QR_CODE, 190, 190, hints);
BufferedImage image = MatrixToImageWriter.toBufferedImage(bitMatrix);
//输出二维码图片流
try {
ImageIO.write(image, "png", response.getOutputStream());
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (WriterException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
- qr.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8"/>
<title></title>
</head>
<body>
<!--The thymeleaf syntax is used here,you need to write your own path-->
<img data-th-src="|${e.front('/qr-img')}?code_url=${code_url}|" style="width:300px;height:300px;"/>
</body>
</html>
- 写到这里你会发现好像少了一个MatrixToImageWriter类,这个类是由google提供,直接copy一份即可
package com.balabala.poet.base.utils;
import com.google.zxing.common.BitMatrix;
import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
/**
* 二维码的生成需要借助MatrixToImageWriter类，该类是由Google提供的，可以将该类直接拷贝到源码中使用
* Created by sam on 16/4/12.
*/
public class MatrixToImageWriter {
private static final int BLACK = 0xFF000000;
private static final int WHITE = 0xFFFFFFFF;
private MatrixToImageWriter() {
}
public static BufferedImage toBufferedImage(BitMatrix matrix) {
int width = matrix.getWidth();
int height = matrix.getHeight();
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
for (int x = 0; x < width; x++) {
for (int y = 0; y < height; y++) {
image.setRGB(x, y, matrix.get(x, y) ? BLACK : WHITE);
}
}
return image;
}
public static void writeToFile(BitMatrix matrix, String format, File file) throws IOException {
BufferedImage image = toBufferedImage(matrix);
if (!ImageIO.write(image, format, file)) {
throw new IOException("Could not write an image of format " + format + " to " + file);
}
}
public static void writeToStream(BitMatrix matrix, String format, OutputStream stream) throws IOException {
BufferedImage image = toBufferedImage(matrix);
if (!ImageIO.write(image, format, stream)) {
throw new IOException("Could not write an image of format " + format);
}
}
}
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