两个工具类：
BufferedImageLuminanceSource
package com.demo.qrcode;
import com.google.zxing.LuminanceSource;
import java.awt.*;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
/**
* 用于二维码的解析 Google提供
*/
public class BufferedImageLuminanceSource extends LuminanceSource {
private final BufferedImage image;
private final int left;
private final int top;
public BufferedImageLuminanceSource(BufferedImage image){
this(image,0,0,image.getWidth(),image.getHeight());
}
public BufferedImageLuminanceSource(BufferedImage image,int left,int top,int width,int height){
super(width, height);
int sourceWidth=image.getWidth();
int sourceHeight=image.getHeight();
if (left + width > sourceWidth || top + height>sourceHeight){
throw new IllegalArgumentException("Crop rectangle does not fit within image data.");
}
for (int y=top;y<top+height;y++){
for (int x=left;x<left+width;x++){
if ((image.getRGB(x, y) & 0xFF000000) == 0) {
image.setRGB(x, y, 0xFFFFFFFF); // = white
}
}
}
this.image = new BufferedImage(sourceWidth,sourceHeight,BufferedImage.TYPE_BYTE_GRAY);
this.image.getGraphics().drawImage(image,0,0,null);
this.left=left;
this.top=top;
}
@Override
public byte[] getRow(int y, byte[] row) {
if (y<0 || y>getHeight()){
throw new IllegalArgumentException("Requested row is outside the image: " + y);
}
int width = getWidth();
if (row == null || row.length < width){
row = new byte[width];
}
image.getRaster().getDataElements(left, top + y, width, 1, row);
return row;
}
@Override
public byte[] getMatrix() {
int width = getWidth();
int height = getHeight();
int area = width * height;
byte[] matrix = new byte[area];
image.getRaster().getDataElements(left, top, width, height, matrix);
return matrix;
}
@Override
public boolean isCropSupported() {
return true;
}
@Override
public LuminanceSource crop(int left, int top, int width, int height) {
return new BufferedImageLuminanceSource(image, this.left + left, this.top + top, width, height);
}
@Override
public boolean isRotateSupported() {
return true;
}
@Override
public LuminanceSource rotateCounterClockwise() {
int sourceWidth = image.getWidth();
int sourceHeight = image.getHeight();
AffineTransform transform = new AffineTransform(0.0, -1.0, 1.0, 0.0, 0.0, sourceWidth);
BufferedImage rotatedImage = new BufferedImage(sourceHeight, sourceWidth, BufferedImage.TYPE_BYTE_GRAY);
Graphics2D g = rotatedImage.createGraphics();
g.drawImage(image, transform, null);
g.dispose();
int width = getWidth();
return new BufferedImageLuminanceSource(rotatedImage, top, sourceWidth - (left + width), getHeight(), width);
}
}
MatrixToImageWriter
package com.demo.qrcode;
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;
/**
* 用于二维码的生成 Google提供
*/
public final 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);
}
}
}
使用类中放置两个方法
private String generateQRCode(String text, int width, int height, String format) throws Exception {
Hashtable<EncodeHintType, Object> hints = new Hashtable<>();
hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
BitMatrix bitMatrix = new MultiFormatWriter().encode(text, BarcodeFormat.QR_CODE, width, height, hints);
String pathName = "D:/Java/new.png";
File file = new File(pathName);
if (file.exists()) file.delete();
File outputFile = new File(pathName);
MatrixToImageWriter.writeToFile(bitMatrix, format, outputFile);
return pathName;
}
/**
* 解析指定路径下的二维码图片
*
* @param filePath 二维码图片路径
* @return
*/
private String parseQRCode(String filePath) {
String content = "";
try {
File file = new File(filePath);
BufferedImage image = ImageIO.read(file);
LuminanceSource source = new BufferedImageLuminanceSource(image);
Binarizer binarizer = new HybridBinarizer(source);
BinaryBitmap binaryBitmap = new BinaryBitmap(binarizer);
Map<DecodeHintType, Object> hints = new HashMap<>();
hints.put(DecodeHintType.CHARACTER_SET, "UTF-8");
MultiFormatReader formatReader = new MultiFormatReader();
Result result = formatReader.decode(binaryBitmap, hints);
System.out.println("result 为：" + result.toString());
System.out.println("resultFormat 为：" + result.getBarcodeFormat());
System.out.println("resultText 为：" + result.getText());
//设置返回值
content = result.getText();
} catch (Exception e) {
e.printStackTrace();
}
return content;
}调用生成
String text = "器材名：\n"+
"可用次数：";
int width = 200; //二维码图片的宽
int height = 200; //二维码图片的高
String format = "png"; //二维码图片的格式
//生成二维码图片，并返回图片路径
String pathName = generateQRCode(text, width, height, format);
System.out.println("生成二维码的图片路径： " + pathName);
String content = parseQRCode(pathName);
System.out.println("解析出二维码的图片的内容为： " + content);?如果需要实现图片预览，可以借鉴此篇博客，前端将application/pdf改为image/jpeg就行：