qr 生成二维码

package com.common;

import com.swetake.util.Qrcode;
import jp.sourceforge.qrcode.QRCodeDecoder;
import com.swetake.util.Qrcode;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

/**
 * Created by lxl on 2016-09-10.
 */
public class QRCodeUtils {

    /**
     * 生成二维码
     * @param qrContent 存入的内容
     * @param w 二维码 宽度
     * @param h 二维码 高度
     * @param filePath 二维码 存储路径
     * @param fileName 二维码 名称
     * @return 返回文件名称
     */
    public static String encoderQRCode(String qrContent, int w, int h, String filePath, String fileName) {
        Lock lock = new ReentrantLock();
        lock.lock();
        String FilePath = "";
        try {
            Qrcode qrcode = new Qrcode();
            qrcode.setQrcodeErrorCorrect('M');
            qrcode.setQrcodeEncodeMode('B');
            qrcode.setQrcodeVersion(7);
            //如果给定的路径不存在创建
            File fp = new File(filePath);
            if (!fp.exists()) {
                fp.mkdirs();
            }
            byte[] d = new byte[0];
            try {
                d = qrContent.getBytes("GBK");
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            }
            BufferedImage bi = new BufferedImage(139, 139, BufferedImage.TYPE_INT_RGB);
            // createGraphics
            Graphics2D g = bi.createGraphics();
            // set background
            g.setBackground(Color.WHITE);
            g.clearRect(0, 0, w, h);
            g.setColor(Color.BLACK);

            if (d.length > 0 && d.length < 123) {
                boolean[][] b = qrcode.calQrcode(d);
                for (int ii = 0; ii < b.length; ii++) {
                    for (int j = 0; j < b.length; j++) {
                        if (b[j][ii]) {
                            g.fillRect(j * 3 + 2, ii * 3 + 2, 3, 3);
                        }
                    }
                }
            }
            g.dispose();
            bi.flush();

            FilePath = filePath + fileName;
            File f = new File(FilePath);

            try {
                ImageIO.write(bi, "png", f);
            } catch (IOException e) {
                e.printStackTrace();
            }
        } catch (Exception e) {
        } finally {
            lock.unlock();
        }
        System.out.println("doned!");
        return fileName;
    }

    /**
     * 读取二维码内容
     * @param imageFile
     * @return
     */
    public static String decoderQRCode(File imageFile) {
        Lock lock = new ReentrantLock();
        lock.lock();
        String decodedData = null;
        try {
            QRCodeDecoder decoder = new QRCodeDecoder();
            BufferedImage image = null;
            try {
                image = ImageIO.read(imageFile);
            } catch (IOException e) {
                System.out.println("Error: " + e.getMessage());
            }

            try {
                decodedData = new String(decoder.decode(new J2SEImage(image)), "GBK");
                System.out.println("Output Decoded Data is：" + decodedData);
            } catch (Exception dfe) {
                System.out.println("Error: " + dfe.getMessage());
            }
        } catch (Exception e) {
        } finally {
            lock.unlock();
        }
        return decodedData;
    }
}

------------------------------------------------------------end--------------------------------------------------------------------------

下面部分是扩展部分

二维中不仅可以存储字符，还可以存储图片，需要将要存储的图片转换成字节流，注意图片最大只可以存储2kb左右，对你没有听错，就是2kb

/**
     * 将指定的图片转换为字节
     * @param path
     * @return
     */
    public static byte[] image2byte(String path){
        byte[] data = null;
        FileImageInputStream input = null;
        try {
            input = new FileImageInputStream(new File(path));
            ByteArrayOutputStream output = new ByteArrayOutputStream();
            byte[] buf = new byte[1024];
            int numBytesRead = 0;
            while ((numBytesRead = input.read(buf)) != -1) {
                output.write(buf, 0, numBytesRead);
            }
            data = output.toByteArray();
            output.close();
            input.close();
        }
        catch (FileNotFoundException ex1) {
            ex1.printStackTrace();
        }
        catch (IOException ex1) {
            ex1.printStackTrace();
        }
        return data;
    }

将二维码中读取出的字节转换成图片

    /**
     * 将二维码中读取出的字节转换成图片
     * @param data
     * @param path
     */
    public static void byte2image(byte[] data,String path){
        if(data.length<3||path.equals("")) return;
        try{
            FileImageOutputStream imageOutput = new FileImageOutputStream(new File(path));
            imageOutput.write(data, 0, data.length);
            imageOutput.close();
        } catch(Exception ex) {
            System.out.println("Exception: " + ex);
            ex.printStackTrace();
        }
    }

完成代码

package hbxt;

import com.swetake.util.Qrcode;
import jp.sourceforge.qrcode.QRCodeDecoder;
import jp.sourceforge.qrcode.exception.DecodingFailedException;
import org.apache.commons.codec.binary.Base64;

import javax.imageio.ImageIO;
import javax.imageio.stream.FileImageInputStream;
import javax.imageio.stream.FileImageOutputStream;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.*;

/**
 * Hello world!
 *
 */
public class App 
{
    static int size=40;
    // 图片尺寸
    static int imgSize = 500 + 12 * (size - 1);
    public static byte[] createQRCode(String imgPath) {
        byte[] result = null;
        try {
            Qrcode qrcodeHandler = new Qrcode();
            qrcodeHandler.setQrcodeErrorCorrect('M');
            qrcodeHandler.setQrcodeEncodeMode('B');
            qrcodeHandler.setQrcodeVersion(size);

            byte[] contentBytes =image2byte(imgPath); 
            BufferedImage bufferImgage = new BufferedImage(imgSize, imgSize, BufferedImage.TYPE_INT_RGB);

            Graphics2D graphics2D = bufferImgage.createGraphics();
            graphics2D.setBackground(Color.WHITE);
            graphics2D.clearRect(0, 0, imgSize, imgSize);
            graphics2D.setColor(Color.BLACK);
            int pixoff = 10;
            if (contentBytes.length > 0 && contentBytes.length < 3000) {
                boolean[][] matrix = qrcodeHandler.calQrcode(contentBytes);
                for (int i = 0; i < matrix.length; i++) {
                    for (int j = 0; j < matrix.length; j++) {
                        if (matrix[j][i]) {
                            graphics2D.fillRect(j * 4 + pixoff, i * 4 + pixoff, 4, 4);
                        }
                    }
                }
            } else {
            }
            graphics2D.dispose();
            bufferImgage.flush();
            ByteArrayOutputStream output = new ByteArrayOutputStream();
            ImageIO.write(bufferImgage, "png", output);
            result = output.toByteArray();
            output.close();

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

    public static void saveImage(byte[] data, String fileName,String type) {
        BufferedImage image = new BufferedImage(imgSize, imgSize, BufferedImage.TYPE_BYTE_BINARY);
        ByteArrayOutputStream byteOutputStream = new ByteArrayOutputStream();
        try {
            ImageIO.write(image, type, byteOutputStream);
            // byte[] date = byteOutputStream.toByteArray();
            byte[] bytes =  data;
            System.out.println("path:" + fileName);
            RandomAccessFile file = new RandomAccessFile(fileName, "rw");
            file.write(bytes);
            file.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 将二维码中读取出的字节转换成图片
     * @param data
     * @param path
     */
    public static void byte2image(byte[] data,String path){
        if(data.length<3||path.equals("")) return;
        try{
            FileImageOutputStream imageOutput = new FileImageOutputStream(new File(path));
            imageOutput.write(data, 0, data.length);
            imageOutput.close();
        } catch(Exception ex) {
            System.out.println("Exception: " + ex);
            ex.printStackTrace();
        }
    }

    /**
     * 解析二维码（QRCode）
     * @param imgPath 图片路径
     * @return
     */
    public static String decoderQRCode(String imgPath) {
        // QRCode 二维码图片的文件
        File imageFile = new File(imgPath);
        BufferedImage bufImg = null;
        String content = null;
        try {
            bufImg = ImageIO.read(imageFile);
            QRCodeDecoder decoder = new QRCodeDecoder();
            content = new String(decoder.decode(new TwoDimensionCodeImage(bufImg)), "utf-8");
        } catch (IOException e) {
            System.out.println("Error: " + e.getMessage());
            e.printStackTrace();
        } catch (DecodingFailedException dfe) {
            System.out.println("Error: " + dfe.getMessage());
            dfe.printStackTrace();
        }
        return content;
    }

    /**
     * 将指定的图片转换为字节
     * @param path
     * @return
     */
    public static byte[] image2byte(String path){
        byte[] data = null;
        FileImageInputStream input = null;
        try {
            input = new FileImageInputStream(new File(path));
            ByteArrayOutputStream output = new ByteArrayOutputStream();
            byte[] buf = new byte[1024];
            int numBytesRead = 0;
            while ((numBytesRead = input.read(buf)) != -1) {
                output.write(buf, 0, numBytesRead);
            }
            data = output.toByteArray();
            output.close();
            input.close();
        }
        catch (FileNotFoundException ex1) {
            ex1.printStackTrace();
        }
        catch (IOException ex1) {
            ex1.printStackTrace();
        }
        return data;
    }

    public static void main(String[] args) {
        byte[]  imgs=App.createQRCode("d:/2.gif");
        App.saveImage(imgs, "D:/1.png", "png");
        System.out.println(imgs);
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        decoderQRCode("D:/1.png");

    }
}

扩展类：

package hbxt;

import jp.sourceforge.qrcode.data.QRCodeImage;

import java.awt.image.BufferedImage;

/**
 * Created by Administrator on 2016-10-20.
 */
public class TwoDimensionCodeImage implements QRCodeImage {
    BufferedImage bufImg;

    public TwoDimensionCodeImage(BufferedImage bufImg) {
        this.bufImg = bufImg;
    }

    @Override
    public int getHeight() {
        return bufImg.getHeight();
    }

    @Override
    public int getPixel(int x, int y) {
        return bufImg.getRGB(x, y);
    }

    @Override
    public int getWidth() {
        return bufImg.getWidth();
    }

}

maven:

<dependency>
      <groupId>com.xiongyingqi</groupId>
      <artifactId>qrcode</artifactId>
      <version>0.1.10</version>
    </dependency>