Java---利用Zing生成二维码、解析二维码

Zxing是一个开源的 用Java实现的多种格式的1D/2D条码图像处理库，可以生成、解析二维码。

二维码它就是把一段纯文本用图形样式转换出来了，以便于快速扫描读出

首先，新建一个Java工程，然后导入需要的Zxing jar包，

工程结构如下:

1.二维码生成

1.1将源码中关于二维码生成的类拷贝进来，

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import javax.imageio.ImageIO;
import com.google.zxing.common.BitMatrix;

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);
}
}
}

1.2在main方法中编写实现二维码生成的方法

private static void generateCode() {
try {

String content = "http://www.baidu.com";
String path = "C:\\Users\\Dong\\Desktop\\testImage";
File dir = new File(path);
if (!dir.exists()) {
dir.mkdir();
}
MultiFormatWriter multiFormatWriter = new MultiFormatWriter();

Map hints = new HashMap();
hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
BitMatrix bitMatrix = multiFormatWriter.encode(content,
BarcodeFormat.QR_CODE, 400, 400, hints);
File file1 = new File(dir, "url.png");

MatrixToImageWriter.writeToFile(bitMatrix, "png", file1);
System.out.println("二维码生成成功!");
} catch (Exception e) {
e.printStackTrace();
}
}

2.二维码解析

2.1 将源码中关于二维码解析的类拷贝进来

import com.google.zxing.LuminanceSource;
import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;

public final 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);
}

}

2.1 编写实现二维码解析的方法

private static void decode() {
try {
MultiFormatReader formatReader = new MultiFormatReader();
String filePath = "C:\\Users\\Dong\\Desktop\\testImage\\url.png";
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 hints = new HashMap();
hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
Result result = formatReader.decode(binaryBitmap, hints);

System.out.println("result = " + result.toString());
System.out.println("resultFormat = " + result.getBarcodeFormat());
System.out.println("resultText = " + result.getText());

} catch (Exception e) {
e.printStackTrace();
}
}

解析结果



参考：

- /article/5506775.html

- https://www.zhihu.com/question/21096632

源码下载