package com.zzl.controller.demo;import com.google.zxing.*;import com.google.zxing.client.j2se.BufferedImageLuminanceSource;import com.google.zxing.client.j2se.MatrixToImageWriter;import com.google.zxing.common.BitMatrix;import com.google.zxing.common.HybridBinarizer;import com.google.zxing.qrcode.QRCodeWriter;import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;import javax.imageio.ImageIO;import java.awt.image.BufferedImage;import java.io.File;import java.io.IOException;import java.io.UnsupportedEncodingException;import java.nio.ByteBuffer;import java.nio.CharBuffer;import java.nio.charset.CharacterCodingException;import java.nio.charset.Charset;import java.nio.charset.CharsetEncoder;import java.util.Hashtable;/** * Class Object is the root of the class hierarchy. * Every class has Object as a superclass. All objects, * including arrays, implement the methods of this class. * * @author Administrator * @version 1.0 * @see * @since JDK1.7 * 
 * History * Created by Administrator on 2017/12/11 0011. */public class QRcodeDemo {    private static Hashtable hints = new Hashtable();    {        //设置二维码排错率，可选L(7%) M(15%) Q(25%) H(30%)，排错率越高可存储的信息越少，但对二维码清晰度的要求越小         hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.Q);    }    public static void main(String[] args) throws Exception{        String filePath = "C:\\Users\\Administrator\\Desktop\\1.jpg";        encode("http://www.baidu.com/", filePath);        decode(filePath);    }    // qrcode 编码    public static void encode(String conent, String filePath) throws Exception{        BitMatrix matrix = null;        int h = 200;        int w = 200;        QRCodeWriter writer = new QRCodeWriter();        try {            matrix = writer.encode(conent, BarcodeFormat.QR_CODE, h, w, hints);            File file = new File(filePath);            MatrixToImageWriter.writeToFile(m, "PNG", file);        } catch (com.google.zxing.WriterException e) {            System.out.println(e.getMessage());        }    }    // qrcode 解码    public static void decode(String file) {        try {            Result result = null;            BufferedImage image = null;            image = ImageIO.read(new File(file));            LuminanceSource source = new BufferedImageLuminanceSource(image);            BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));            Hashtable
     
       hints = new Hashtable
      
       ();            hints.put(DecodeHintType.CHARACTER_SET, "UTF-8");            result = new MultiFormatReader().decode(bitmap, hints);            String rtn = result.getText();            System.out.println(rtn);            System.out.println(rtn.length());        } catch (Exception ex) {            System.out.println(ex.toString());        }    }}
      
     

生成的二维码图片：

上面二维码旁边会有一圈白边的，如果要想去掉白边，加上下面这段代码

在输出前调用deleteWhite()方法：

m= deleteWhite(m);//删除白边MatrixToImageWriter.writeToFile(m, "PNG", file);

private static BitMatrix deleteWhite(BitMatrix matrix) {        int[] rec = matrix.getEnclosingRectangle();        int resWidth = rec[2] + 1;        int resHeight = rec[3] + 1;        BitMatrix resMatrix = new BitMatrix(resWidth, resHeight);        resMatrix.clear();        for (int i = 0; i < resWidth; i++) {            for (int j = 0; j < resHeight; j++) {                if (matrix.get(i + rec[0], j + rec[1]))                    resMatrix.set(i, j);            }        }        return resMatrix;    }