如今二維碼這么流行的時刻。也必須知道二維碼是怎么生成。如今我們就來看看，是怎么生成的。
事實上主要是利用goggle公布的jar來使用：本文轉自點擊打開鏈接
1、二維碼的生成
將Zxing-core.jar 包增加到classpath下。
二維碼的生成須要借助MatrixToImageWriter類，該類是由Google提供的，能夠將該類復制到源代碼中。這里我將該類的源代碼貼上，能夠直接使用。
直接能夠生成二維碼的代碼
public void test1() throws Exception{
String content = "www.baidu.com";
String path = "d://";
MultiFormatWriter multiFormatWriter = new MultiFormatWriter();//Zxing是Google提供的關於條碼
Map hints = new HashMap();
hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
BitMatrix bitMatrix = multiFormatWriter.encode(content, BarcodeFormat.QR_CODE, 400, 400,hints);//這里是照片的大小
File file1 = new File(path,"my.jpg");
MatrixToImageWriter.writeToFile(bitMatrix, "jpg", file1);
System.out.println("運行完成");
}
當我們能發現，這個代碼拷貝上后發現有一個
MatrixToImageWriter報錯，所以須要我們去找。可是這里我貼出代碼，能夠直接使用。
import com.google.zxing.common.BitMatrix;
import javax.imageio.ImageIO;
import java.io.File;
import java.io.OutputStream;
import java.io.IOException;
import java.awt.image.BufferedImage;
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);
}
}
}
如今就能夠d盤的根文件夾下載看生成的二維碼了
二維碼解析
和生成一樣，我們須要一個輔助類（ BufferedImageLuminanceSource），相同該類Google也提供了，這里我相同將該類的源代碼貼出來，能夠直接拷貝使用個，省去查找的麻煩
BufferedImageLuminanceSource
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);
}
}
解析二維碼的代碼
MultiFormatReader formatReader = new MultiFormatReader();
String filePath = "圖片的路徑";
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();
}
如今這樣能夠在控制台看到二維碼的內容。
純粹是筆記。