首先前台使用的是vue，用到的生成二维码工具类ZxingUtil
<a v-bind:href="'${ctx}/admin/activity/activityDetailQRCode.do?recno='+item.recno" class="btn btn-danger btn-xs" v-bind:download="item.name+'.jpg'" style="padding:1px 5px;font-size: 14px;margin-top: 5px">下载活动报名二维码</a>
后台
//生成活动报名二维码 @RequestMapping("activityDetailQRCode") @ResponseBody public void activityDetailQRCode(HttpServletRequest request,HttpServletResponse response,Integer recno){ String realPath = request.getServletContext().getRealPath("/"); File dir = new File(realPath+File.separator+"activityDetailQRCode"); if(!dir.exists()){ dir.mkdir(); } String activityQrcodeLink = dir.getAbsolutePath() + File.separator + recno + ".jpg"; File file = new File(activityQrcodeLink); if (!file.exists()) { try { file.createNewFile(); //获取网络协议 String networkProtocol = request.getScheme(); //网络IP String ip = request.getServerName(); //端口号 int port = request.getServerPort(); //项目发布路径 String webApp = request.getContextPath(); //url:${ctx}/mobile/activity/activityDetail.do?activityRecno=" + recno String activityDetailQrcodeLink = networkProtocol+"://"+ip+":"+port+webApp+"/mobile/activity/activityDetail.do?activityRecno="+recno; ZxingUtil.encode2DCode(file, activityDetailQrcodeLink); } catch (WriterException | IOException e) { e.printStackTrace(); } } response.setContentType("image/jpg"); BufferedInputStream inputStream =null; BufferedOutputStream outputStream = null; try { inputStream = new BufferedInputStream(new FileInputStream(file)); outputStream = new BufferedOutputStream(response.getOutputStream()); flushStream(inputStream, outputStream); } catch (IOException e) { e.printStackTrace(); }finally { try { if(inputStream!=null){ inputStream.close(); } if(outputStream!=null){ outputStream.close(); } } catch (IOException e) { e.printStackTrace(); } } }
然后调用一个方法，刷新缓冲流
private void flushStream(InputStream fis, OutputStream os) throws IOException {//刷新字节流
int count = 0;
byte[] buffer = new byte[1024 * 8];
while ((count = fis.read(buffer)) != -1) {
os.write(buffer, 0, count);
os.flush();
}
}
----补充 之前一直有人找我要工具类 我现在贴下面
然后的话需要两个依赖
这里把maven依赖贴上
<dependency>
<groupId>com.google.zxing</groupId>
<artifactId>core</artifactId>
<version>3.3.0</version>
</dependency>
package com.common.utils;
import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;
import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.geom.AffineTransform;
import java.awt.image.AffineTransformOp;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.util.HashMap;
import java.util.Map;
public class ZxingUtil {
private static final int BLACK = 0xFF000000;
private static final int WHITE = 0xFFFFFFFF;
private static final int DEFAULT_HEIGHT = 300;// 二维码图片宽度
private static final int DEFAULT_WIDTH = 300;// 二维码图片高度
private static final String DEFAULT_FORMAT = "gif";// 二维码的图片格式
private static final int BARCODE_HEIGHT = 30;
private static final int BARCODE_WIDTH = 150;
private static final String BARCODE_FORMAT = "png";
/**
* 生成二维码 到指定 路径 、
*
* @param outputStream
* 到指定 路径 、FILE
* @param text
* 可以是网址 和 其他，网址就是跳转
* @throws WriterException
* @throws IOException
*/
public static void encode2DCode(OutputStream outputStream, String text)
throws WriterException, IOException {
Map<EncodeHintType, Object> hints = new HashMap<EncodeHintType, Object>();
hints.put(EncodeHintType.CHARACTER_SET, "utf-8"); // 内容所使用字符集编码
hints.put(EncodeHintType.MARGIN, 1);
BitMatrix bitMatrix = new MultiFormatWriter().encode(text,
BarcodeFormat.QR_CODE, DEFAULT_WIDTH, DEFAULT_HEIGHT, hints);
BufferedImage image = toBufferedImage(bitMatrix);
/*
* Graphics2D gs = image.createGraphics(); //载入logo Image img =
* ImageIO.read(new File(srcImagePath)); gs.drawImage(img, 125, 125,
* null); gs.dispose(); img.flush();
*/
if (!ImageIO.write(image, DEFAULT_FORMAT, outputStream)) {
throw new IOException("Could not write an image of format "
+ DEFAULT_FORMAT + " to stream");
}
}
/**
* 返回BitMatrix二维码内容
* @param text
* @return
* @throws WriterException
*/
public static BitMatrix encode2DCode(String text) throws WriterException {
Map<EncodeHintType, Object> hints = new HashMap<EncodeHintType, Object>();
hints.put(EncodeHintType.CHARACTER_SET, "utf-8"); // 内容所使用字符集编码
hints.put(EncodeHintType.MARGIN, 1);
BitMatrix bitMatrix = new MultiFormatWriter().encode(text,
BarcodeFormat.QR_CODE, DEFAULT_WIDTH, DEFAULT_HEIGHT, hints);
return bitMatrix;
}
/**
*
* @param outputFile
* 到指定路径
* @param text
* 可以是网址 和 其他内容，网址就是跳转
* @param width
* 二维码 宽度
* @param height
* 二维码高度
* @param format
* 生成二维码的图片格式
* @throws WriterException
* @throws IOException
*/
public static void encode2DCode(File outputFile, String text, int width,
int height, String format) throws WriterException, IOException {
// 读取源图像
Map<EncodeHintType, String> hints = new HashMap<EncodeHintType, String>();
hints.put(EncodeHintType.CHARACTER_SET, "utf-8"); // 内容所使用字符集编码
BitMatrix bitMatrix = new MultiFormatWriter().encode(text,
BarcodeFormat.QR_CODE, width, height, hints);
writeToFile(bitMatrix, format, outputFile);
}
/**
* 生成条码号
*
* <p>2017年1月17日 下午1:56:33
* <p>create by hjc
* @throws WriterException
* @throws IOException
*/
public static void encodeBarcode(File outputFile, String text) throws WriterException, IOException{
Map<EncodeHintType, Object> hints = new HashMap<EncodeHintType, Object>();
// hints.put(EncodeHintType.CHARACTER_SET, "utf-8"); // 内容所使用字符集编码
// hints.put(EncodeHintType.MARGIN, 1);
BitMatrix bitMatrix = new MultiFormatWriter().encode(text,
BarcodeFormat.CODE_128, BARCODE_WIDTH, BARCODE_HEIGHT, hints);
writeToFile(bitMatrix, BARCODE_FORMAT, outputFile);
}
public static BufferedImage toBufferedImage(BitMatrix matrix)
throws IOException {
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,String srcImagePath)
throws IOException {
BufferedImage image = toBufferedImage(matrix);
Graphics2D gs = image.createGraphics(); //载入logo
Image img = ImageIO.read(new File(srcImagePath));
gs.drawImage(img, 125, 125, null);
gs.dispose();
img.flush();
if (!ImageIO.write(image, format, file)) {
throw new IOException("Could not write an image of format "
+ format + " to " + file);
}
}
public static void writeToFile(BitMatrix matrix, String format, File file)
throws IOException {
BufferedImage image = toBufferedImage(matrix);
/*
* Graphics2D gs = image.createGraphics(); //载入logo Image img =
* ImageIO.read(new File(srcImagePath)); gs.drawImage(img, 125, 125,
* null); gs.dispose(); img.flush();
*/
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);
}
}
/**
* 把传入的原始图像按高度和宽度进行缩放，生成符合要求的图标
*
* @param srcImageFile
* 源文件地址
* @param height
* 目标高度
* @param width
* 目标宽度
* @param hasFiller
* 比例不对时是否需要补白：true为补白; false为不补白;
* @throws IOException
*/
@SuppressWarnings("unused")
private static BufferedImage scale(String srcImageFile, int height,
int width, boolean hasFiller) throws IOException {
double ratio = 0.0; // 缩放比例
File file = new File(srcImageFile);
BufferedImage srcImage = ImageIO.read(file);
Image destImage = srcImage.getScaledInstance(width, height,
BufferedImage.SCALE_SMOOTH);
// 计算比例
if ((srcImage.getHeight() > height) || (srcImage.getWidth() > width)) {
if (srcImage.getHeight() > srcImage.getWidth()) {
ratio = (new Integer(height)).doubleValue()
/ srcImage.getHeight();
} else {
ratio = (new Integer(width)).doubleValue()
/ srcImage.getWidth();
}
AffineTransformOp op = new AffineTransformOp(
AffineTransform.getScaleInstance(ratio, ratio), null);
destImage = op.filter(srcImage, null);
}
if (hasFiller) {// 补白
BufferedImage image = new BufferedImage(width, height,
BufferedImage.TYPE_INT_RGB);
Graphics2D graphic = image.createGraphics();
graphic.setColor(Color.white);
graphic.fillRect(0, 0, width, height);
if (width == destImage.getWidth(null))
graphic.drawImage(destImage, 0,
(height - destImage.getHeight(null)) / 2,
destImage.getWidth(null), destImage.getHeight(null),
Color.white, null);
else
graphic.drawImage(destImage,
(width - destImage.getWidth(null)) / 2, 0,
destImage.getWidth(null), destImage.getHeight(null),
Color.white, null);
graphic.dispose();
destImage = image;
}
return (BufferedImage) destImage;
}
public static void scale(String srcImageFile, String result, int scale,
boolean flag) {
try {
BufferedImage src = ImageIO.read(new File(srcImageFile)); // 读入文件
int width = src.getWidth(); // 得到源图宽
int height = src.getHeight(); // 得到源图长
if (flag) {
// 放大
width = width * scale;
height = height * scale;
} else {
// 缩小
width = width / scale;
height = height / scale;
}
Image image = src.getScaledInstance(width, height,
Image.SCALE_SMOOTH);
BufferedImage tag = new BufferedImage(width, height,
BufferedImage.TYPE_INT_RGB);
Graphics g = tag.getGraphics();
g.drawImage(image, 0, 0, null); // 绘制缩小后的图
g.dispose();
ImageIO.write(tag, "JPEG", new File(result));// 输出到文件流
} catch (IOException e) {
e.printStackTrace();
}
}
}