生成二维码（java后端）

需要引入2个jar包：

<dependency>

    <groupId>com.google.zxing</groupId>

    <artifactId>javase</artifactId>

    <version>3.3.1</version>

</dependency>

<!-- https://mvnrepository.com/artifact/com.google.zxing/core -->

<dependency>

    <groupId>com.google.zxing</groupId>

    <artifactId>core</artifactId>

    <version>3.3.1</version>

</dependency>

生成方法如下：

package com.payplatform.util;

import java.awt.image.BufferedImage;

import java.io.File;

import java.io.IOException;

import java.util.HashMap;

import java.util.Map;

import javax.imageio.ImageIO;

import com.google.zxing.BarcodeFormat;

import com.google.zxing.Binarizer;

import com.google.zxing.BinaryBitmap;

import com.google.zxing.EncodeHintType;

import com.google.zxing.LuminanceSource;

import com.google.zxing.MultiFormatReader;

import com.google.zxing.MultiFormatWriter;

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;

public class QRCodeUtil {

	//二维码颜色

    private static final int BLACK = 0xFF000000;

    //二维码颜色

    private static final int WHITE = 0xFFFFFFFF;

    public static void main(String[] args) throws Exception {

		zxingCodeCreate("http://www.baidu.com", 300, 300, "D:/qrcode.jpg", "jpg");

//    	zxingCodeAnalyze("D:/qrcode.jpg");

	}

    /**

     * 生成二维码

     * @param text    二维码内容

     * @param width    二维码宽

     * @param height    二维码高

     * @param outPutPath    二维码生成保存路径

     * @param imageType     二维码生成格式

     */

    public static void zxingCodeCreate(String text, int width, int height, String outPutPath, String imageType){

        Map<EncodeHintType, String> his = new HashMap<EncodeHintType, String>();

        //设置编码字符集

        his.put(EncodeHintType.CHARACTER_SET, "utf-8");

        try {

            //1、生成二维码

            BitMatrix encode = new MultiFormatWriter().encode(text, BarcodeFormat.QR_CODE, width, height, his);

            //2、获取二维码宽高

            int codeWidth = encode.getWidth();

            int codeHeight = encode.getHeight();

            //3、将二维码放入缓冲流

            BufferedImage image = new BufferedImage(codeWidth, codeHeight, BufferedImage.TYPE_INT_RGB);

            for (int i = 0; i < codeWidth; i++) {

                for (int j = 0; j < codeHeight; j++) {

                    //4、循环将二维码内容定入图片

                    image.setRGB(i, j, encode.get(i, j) ? BLACK : WHITE);

                }

            }

            File outPutImage = new File(outPutPath);

            //如果图片不存在创建图片

            if(!outPutImage.exists())

                outPutImage.createNewFile();

            //5、将二维码写入图片

            ImageIO.write(image, imageType, outPutImage);

        } catch (WriterException e) {

            e.printStackTrace();

            System.out.println("二维码生成失败");

        } catch (IOException e) {

            e.printStackTrace();

            System.out.println("生成二维码图片失败");

        }

    }

    /**

     * 二维码解析

     * @param analyzePath    二维码路径

     * @return

     * @throws IOException

     */

    @SuppressWarnings({ "rawtypes", "unchecked" })

    public static String zxingCodeAnalyze(String analyzePath) throws Exception{

        MultiFormatReader formatReader = new MultiFormatReader();

        String resultStr = null;

        try {

            File file = new File(analyzePath);

            if (!file.exists())

            {

                return "二维码不存在";

            }

            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);

            resultStr = result.getText();

        } catch (NotFoundException e) {

            e.printStackTrace();

        }

        System.out.println(resultStr);

        return resultStr;

    }

}