java使用jar包生成二维码的示例代码

使用java进行二维码的生成与读取使用到了谷歌的zxing.jar

第一步 导入，maven依赖或者下载指定jar包

  com.google.zxing
  javase
  3.2.1

第二步 书写二维码生成器的工具类

import java.awt.Color;
import java.io.File;
import java.util.Hashtable;
import com.google.zxing.EncodeHintType;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;

public class QRCodeFormat {
 
  
  private int size;
 
  
  private String encode;
 
  
  private ErrorCorrectionLevel errorCorrectionLevel;
 
  
  private double errorCorrectionLevelValue;
 
  
  private Color foreGroundColor;
 
  
  private Color backGroundColor;
 
  
  private String imageFormat;
 
  
  private int margin;
 
  
  private Hashtable hints;
 
  
  private File icon;
 
  
  public static QRCodeFormat NEW() {
    return new QRCodeFormat();
  }
 
  private QRCodeFormat() {
    this.size = 256;
    this.encode = "utf-8";
    this.errorCorrectionLevel = ErrorCorrectionLevel.M;
    this.errorCorrectionLevelValue = 0.15;
    this.foreGroundColor = Color.BLACK;
    this.backGroundColor = Color.WHITE;
    this.imageFormat = "png";
    this.margin = 0;
    this.hints = new Hashtable();
  }
 
  
  public int getSize() {
    return this.size;
  }
 
  
  public QRCodeFormat setSize(int size) {
    this.size = size;
    return this;
  }
 
  
  public String getEncode() {
    return encode;
  }
 
  
  public QRCodeFormat setEncode(String encode) {
    this.encode = encode;
    return this;
  }
 
  
  public ErrorCorrectionLevel getErrorCorrectionLevel() {
    return errorCorrectionLevel;
  }
 
  
  public double getErrorCorrectionLevelValue() {
    return errorCorrectionLevelValue;
  }
 
  
  public QRCodeFormat setErrorCorrectionLevel(char errorCorrectionLevel) {
    switch (Character.toUpperCase(errorCorrectionLevel)) {
    case 'L':
      this.errorCorrectionLevel = ErrorCorrectionLevel.L;
      this.errorCorrectionLevelValue = 0.07;
      break;
    case 'M':
      this.errorCorrectionLevel = ErrorCorrectionLevel.M;
      this.errorCorrectionLevelValue = 0.15;
      break;
    case 'Q':
      this.errorCorrectionLevel = ErrorCorrectionLevel.Q;
      this.errorCorrectionLevelValue = 0.25;
      break;
    case 'H':
      this.errorCorrectionLevel = ErrorCorrectionLevel.H;
      this.errorCorrectionLevelValue = 0.3;
      break;
    default:
      this.errorCorrectionLevel = ErrorCorrectionLevel.M;
    }
 
    return this;
  }
 
  
  public Color getForeGroundColor() {
    return foreGroundColor;
  }
 
  
  public QRCodeFormat setForeGroundColor(String foreGroundColor) {
    try {
      this.foreGroundColor = getColor(foreGroundColor);
    }
    catch (NumberFormatException e) {
      this.foreGroundColor = Color.BLACK;
    }
    return this;
  }
 
  
  public QRCodeFormat setForeGroundColor(Color foreGroundColor) {
    this.foreGroundColor = foreGroundColor;
    return this;
  }
 
  
  public Color getBackGroundColor() {
    return backGroundColor;
  }
 
  
  public QRCodeFormat setBackGroundColor(String backGroundColor) {
    try {
      this.backGroundColor = getColor(backGroundColor);
    }
    catch (NumberFormatException e) {
      this.backGroundColor = Color.WHITE;
    }
    return this;
  }
 
  
  public QRCodeFormat setBackGroundColor(Color backGroundColor) {
    this.backGroundColor = backGroundColor;
    return this;
  }
 
  
  public String getImageFormat() {
    return imageFormat.toUpperCase();
  }
 
  
  public QRCodeFormat setImageFormat(String imageFormat) {
    this.imageFormat = imageFormat;
    return this;
  }
 
  
  public int getMargin() {
    return margin;
  }
 
  
  public QRCodeFormat setMargin(int margin) {
    this.margin = margin;
    return this;
  }
 
  
  public Hashtable getHints() {
    hints.clear();
    hints.put(EncodeHintType.ERROR_CORRECTION, getErrorCorrectionLevel());
    hints.put(EncodeHintType.CHARACTER_SET, getEncode());
    hints.put(EncodeHintType.MARGIN, getMargin());
    return hints;
  }
 
  
  public File getIcon() {
    return icon;
  }
 
  
  public QRCodeFormat setIcon(File icon) {
    this.icon = icon;
    return this;
  }
 
  
  public QRCodeFormat setIcon(String iconPath) {
    return setIcon(new File(iconPath));
  }
 
  private Color getColor(String hexString) {
    if (hexString.charAt(0) == '#') {
      return new Color(Long.decode(hexString).intValue());
    } else {
      return new Color(Long.decode("0xFF" + hexString).intValue());
    }
  }
}

第三步 使用生成器对象按照指定格式进行生成读取二维码

import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.color.ColorSpace;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.nio.charset.Charset;
 
import javax.imageio.ImageIO;
 
import com.google.zxing.BarcodeFormat;
import com.google.zxing.BinaryBitmap;
import com.google.zxing.ChecksumException;
import com.google.zxing.FormatException;
import com.google.zxing.LuminanceSource;
import com.google.zxing.NotFoundException;
import com.google.zxing.Result;
import com.google.zxing.WriterException;
import com.google.zxing.client.j2se.BufferedImageLuminanceSource;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.common.HybridBinarizer;
import com.google.zxing.qrcode.QRCodeReader;
import com.google.zxing.qrcode.QRCodeWriter;
 

public final class QRCode {
 
  
  private QRCodeFormat format = null;
 
  
  private BufferedImage qrcodeImage = null;
 
  
  private File qrcodeFile = null;
 
  
  public BufferedImage getQrcodeImage() {
    return qrcodeImage;
  }
 
  
  public File getQrcodeFile() {
    return qrcodeFile;
  }
 
  private QRCode() {
 
  }
 
  
  public static QRCode NEW(final String content) {
    return NEW(content, QRCodeFormat.NEW());
  }
 
  
  public static QRCode NEW(final String content, QRCodeFormat format) {
    QRCode qrcode = new QRCode();
    qrcode.format = format;
    qrcode.qrcodeImage = toQRCode(content, format);
    return qrcode;
  }
 
  
  public QRCode toFile(String f) {
    return toFile(new File(f), this.format.getIcon());
  }
 
  
  public QRCode toFile(File qrcodeFile) {
    return toFile(qrcodeFile, this.format.getIcon());
  }
 
  
  public QRCode toFile(String qrcodeFile, String appendFile) {
    if (null == appendFile || appendFile.length() == 0) {
      return toFile(new File(qrcodeFile));
    }
    return toFile(new File(qrcodeFile), new File(appendFile));
  }
 
  
  public QRCode toFile(File qrcodeFile, File appendFile) {
    try {
      if (!qrcodeFile.exists()) {
 qrcodeFile.getParentFile().mkdirs();
 qrcodeFile.createNewFile();
      }
 
      if (null != appendFile && appendFile.isFile() && appendFile.length() != 0) {
 appendImage(ImageIO.read(appendFile));
      }
 
      if (!ImageIO.write(this.qrcodeImage, getSuffixName(qrcodeFile), qrcodeFile)) {
 throw new RuntimeException("Unexpected error writing image");
      }
    }
    catch (IOException e) {
      throw new RuntimeException(e);
    }
    this.qrcodeFile = qrcodeFile;
    return this;
  }
 
  private void appendImage(BufferedImage appendImage) {
    appendImage(this.qrcodeImage, appendImage, this.format);
  }
 
  private static void appendImage(BufferedImage qrcodeImage, BufferedImage appendImage, QRCodeFormat format) {
    int baseWidth = qrcodeImage.getWidth();
    int baseHeight = qrcodeImage.getHeight();
 
    // 计算 icon 的最大边长
    // 公式为 二维码面积*错误修正等级*0.4 的开方
    int maxWidth = (int) Math.sqrt(baseWidth * baseHeight * format.getErrorCorrectionLevelValue() * 0.4);
    int maxHeight = maxWidth;
 
    // 获取 icon 的实际边长
    int roundRectWidth = (maxWidth < appendImage.getWidth()) ? maxWidth : appendImage.getWidth();
    int roundRectHeight = (maxHeight < appendImage.getHeight()) ? maxHeight : appendImage.getHeight();
 
    BufferedImage roundRect = new BufferedImage(roundRectWidth, roundRectHeight, BufferedImage.TYPE_INT_ARGB);
 
    Graphics2D g2 = roundRect.createGraphics();
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
    g2.setColor(Color.WHITE);
    g2.fillRoundRect(0, 0, roundRectWidth, roundRectHeight, 27, 27);
    g2.setComposite(AlphaComposite.SrcAtop);
    g2.drawImage(appendImage, 0, 0, roundRectWidth, roundRectHeight, null);
    g2.dispose();
 
    Graphics gc = qrcodeImage.getGraphics();
    gc.setColor(format.getBackGroundColor());
    gc.drawImage(roundRect, (baseWidth - roundRectWidth) / 2, (baseHeight - roundRectHeight) / 2, null);
    gc.dispose();
  }
 
  
  public static BufferedImage toQRCode(String content) {
    return toQRCode(content, null);
  }
 
  
  public static BufferedImage toQRCode(String content, QRCodeFormat format) {
    if (format == null) {
      format = QRCodeFormat.NEW();
    }
 
    content = new String(content.getBytes(Charset.forName(format.getEncode())));
    BitMatrix matrix = null;
    try {
      matrix = new QRCodeWriter().encode(content,
   BarcodeFormat.QR_CODE,
   format.getSize(),
   format.getSize(),
   format.getHints());
    }
    catch (WriterException e) {
      throw new RuntimeException(e);
    }
 
    int width = matrix.getWidth();
    int height = matrix.getHeight();
    int fgColor = format.getForeGroundColor().getRGB();
    int bgColor = format.getBackGroundColor().getRGB();
    BufferedImage image = new BufferedImage(width, height, ColorSpace.TYPE_RGB);
    for (int x = 0; x < width; x++) {
      for (int y = 0; y < height; y++) {
 image.setRGB(x, y, matrix.get(x, y) ? fgColor : bgColor);
      }
    }
 
    File appendFile = format.getIcon();
    if (null != appendFile && appendFile.isFile() && appendFile.length() != 0) {
      BufferedImage appendImage = null;
      try {
 appendImage = ImageIO.read(appendFile);
      }
      catch (IOException e) {
 throw new RuntimeException(e);
      }
 
      appendImage(image, appendImage, format);
    }
 
    return image;
  }
 
  
  public static String from(String qrcodeFile) {
    if (qrcodeFile.startsWith("http://") || qrcodeFile.startsWith("https://")) {
      try {
 return from(new URL(qrcodeFile));
      }
      catch (MalformedURLException e) {
 throw new RuntimeException(e);
      }
    } else {
      return from(new File(qrcodeFile));
    }
  }
 
  
  public static String from(File qrcodeFile) {
    try {
      BufferedImage image = ImageIO.read(qrcodeFile);
      return from(image);
    }
    catch (IOException e) {
      throw new RuntimeException(e);
    }
  }
 
  
  public static String from(URL qrcodeUrl) {
    try {
      BufferedImage image = ImageIO.read(qrcodeUrl);
      return from(image);
    }
    catch (IOException e) {
      throw new RuntimeException(e);
    }
  }
 
  
  public static String from(BufferedImage qrcodeImage) {
    LuminanceSource source = new BufferedImageLuminanceSource(qrcodeImage);
    BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
    String content = null;
    try {
      Result result = new QRCodeReader().decode(bitmap);
      content = result.getText();
    }
    catch (NotFoundException e) {
      throw new RuntimeException(e);
    }
    catch (ChecksumException e) {
      throw new RuntimeException(e);
    }
    catch (FormatException e) {
      throw new RuntimeException(e);
    }
    return content;
  }
 
  private String getSuffixName(File file) {
    String path = file.getAbsolutePath();
 
    if (null == path) {
      return this.format.getImageFormat();
    }
    int pos = path.lastIndexOf('.');
    if (-1 == pos) {
      return this.format.getImageFormat();
    }
    return path.substring(pos + 1).toUpperCase();
  }
  
  public static void main(String[] args) throws IOException {
   String str="https://blog.csdn.net/jiandanyou/article/details/109751418";
   QRCode.NEW(str).toFile("d:\2.jpg");//使用指定字符串生成二维码
   System.out.println(QRCode.from("d:/2.jpg"));//读取解析指定二维码
 }
  
}

第四步 使用

工具类中的方法使用的静态方法，可以直接使用QRCode.方法进行执行

生成二维码方法

QRCode.NEW(str).toFile(url);

str：二维码中包含的字符串（如果包含地址前缀添加http或https 否则不能自动跳转 会解析地址字符串）

url：二维码图片生成位置

QRCode.from(url);

url：要解析二维码图片位置

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