生成二维码的两种方式

时间:2020-01-14
本文章向大家介绍生成二维码的两种方式,主要包括生成二维码的两种方式使用实例、应用技巧、基本知识点总结和需要注意事项,具有一定的参考价值,需要的朋友可以参考一下。

今天项目上做了一个二维码的功能,在此记录一下。

功能描述

点击一个超链接,弹出展示二维码的弹出框。

准备

首先下载好生成二维码需要使用到的jar包,下载地址:http://central.maven.org/maven2/com/google/zxing/core/3.3.2/core-3.3.2.jar

将下载好的jar包导入项目,将以下工具类放到项目中:

package com.util;

import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import com.google.zxing.LuminanceSource;
 
public 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;
    }
 
    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;
    }
 
    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;
    }
 
    public boolean isCropSupported() {
        return true;
    }
 
    public LuminanceSource crop(int left, int top, int width, int height) {
        return new BufferedImageLuminanceSource(image, this.left + left, this.top + top, width, height);
    }
 
    public boolean isRotateSupported() {
        return true;
    }
 
    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);
    }
 
}
package com.util;

import java.awt.BasicStroke;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Shape;
import java.awt.geom.RoundRectangle2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Hashtable;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletResponse;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.BinaryBitmap;
import com.google.zxing.DecodeHintType;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatReader;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.Result;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.common.HybridBinarizer;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
 
public class QRCodeUtil {
    private static final String CHARSET = "utf-8";
    private static final String FORMAT_NAME = "JPG";
    // 二维码尺寸
    private static final int QRCODE_SIZE = 300;
    // LOGO宽度
    private static final int WIDTH = 60;
    // LOGO高度
    private static final int HEIGHT = 60;
 
    private static BufferedImage createImage(String content, String imgPath, boolean needCompress) throws Exception {
        Hashtable hints = new Hashtable();
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
        hints.put(EncodeHintType.CHARACTER_SET, CHARSET);
        hints.put(EncodeHintType.MARGIN, 1);
        BitMatrix bitMatrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, QRCODE_SIZE, QRCODE_SIZE,
                hints);
        int width = bitMatrix.getWidth();
        int height = bitMatrix.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, bitMatrix.get(x, y) ? 0xFF000000 : 0xFFFFFFFF);
            }
        }
        if (imgPath == null || "".equals(imgPath)) {
            return image;
        }
        // 插入图片
        QRCodeUtil.insertImage(image, imgPath, needCompress);
        return image;
    }
 
    private static void insertImage(BufferedImage source, String imgPath, boolean needCompress) throws Exception {
        File file = new File(imgPath);
        if (!file.exists()) {
            System.err.println("" + imgPath + "   该文件不存在!");
            return;
        }
        Image src = ImageIO.read(new File(imgPath));
        int width = src.getWidth(null);
        int height = src.getHeight(null);
        if (needCompress) { // 压缩LOGO
            if (width > WIDTH) {
                width = WIDTH;
            }
            if (height > HEIGHT) {
                height = HEIGHT;
            }
            Image image = src.getScaledInstance(width, height, Image.SCALE_SMOOTH);
            BufferedImage tag = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
            Graphics g = tag.getGraphics();
            g.drawImage(image, 0, 0, null); // 绘制缩小后的图
            g.dispose();
            src = image;
        }
        // 插入LOGO
        Graphics2D graph = source.createGraphics();
        int x = (QRCODE_SIZE - width) / 2;
        int y = (QRCODE_SIZE - height) / 2;
        graph.drawImage(src, x, y, width, height, null);
        Shape shape = new RoundRectangle2D.Float(x, y, width, width, 6, 6);
        graph.setStroke(new BasicStroke(3f));
        graph.draw(shape);
        graph.dispose();
    }
 
    public static void encode(String content, String imgPath, String destPath, boolean needCompress) throws Exception {
        BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress);
        mkdirs(destPath);
        // String file = new Random().nextInt(99999999)+".jpg";
        // ImageIO.write(image, FORMAT_NAME, new File(destPath+"/"+file));
        ImageIO.write(image, FORMAT_NAME, new File(destPath));
    }
 
    public static BufferedImage encode(String content, String imgPath, boolean needCompress) throws Exception {
        BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress);
        return image;
    }
 
    public static void mkdirs(String destPath) {
        File file = new File(destPath);
        // 当文件夹不存在时,mkdirs会自动创建多层目录,区别于mkdir.(mkdir如果父目录不存在则会抛出异常)
        if (!file.exists() && !file.isDirectory()) {
            file.mkdirs();
        }
    }
 
    public static void encode(String content, String imgPath, String destPath) throws Exception {
        QRCodeUtil.encode(content, imgPath, destPath, false);
    }
    // 被注释的方法
    /*
     * public static void encode(String content, String destPath, boolean
     * needCompress) throws Exception { QRCodeUtil.encode(content, null, destPath,
     * needCompress); }
     */
 
    public static void encode(String content, String destPath) throws Exception {
        QRCodeUtil.encode(content, null, destPath, false);
    }
 
    public static void encode(String content, String imgPath, OutputStream output, boolean needCompress)
            throws Exception {
        BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress);
        ImageIO.write(image, FORMAT_NAME, output);
    }
 
    public static void encode(String content, OutputStream output) throws Exception {
        QRCodeUtil.encode(content, null, output, false);
    }
 
    public static String decode(File file) throws Exception {
        BufferedImage image;
        image = ImageIO.read(file);
        if (image == null) {
            return null;
        }
        BufferedImageLuminanceSource source = new BufferedImageLuminanceSource(image);
        BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
        Result result;
        Hashtable hints = new Hashtable();
        hints.put(DecodeHintType.CHARACTER_SET, CHARSET);
        result = new MultiFormatReader().decode(bitmap, hints);
        String resultStr = result.getText();
        return resultStr;
    }
 
    public static String decode(String path) throws Exception {
        return QRCodeUtil.decode(new File(path));
    }
 
    public static void creatRrCode(String contents, int width, int height,HttpServletResponse response) {
        Hashtable hints = new Hashtable();

        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H); //容错级别最高
        hints.put(EncodeHintType.CHARACTER_SET, "utf-8");  //设置字符编码
        hints.put(EncodeHintType.MARGIN, 1);                //二维码空白区域,最小为0也有白边,只是很小,最小是6像素左右
        try {
            BitMatrix bitMatrix = new MultiFormatWriter().encode(contents, BarcodeFormat.QR_CODE, width, height, hints); // 1、读取文件转换为字节数组
//            ByteArrayOutputStream out = new ByteArrayOutputStream();
            BufferedImage image = toBufferedImage(bitMatrix);
            //转换成png格式的IO流
            ImageIO.write(image, "png", response.getOutputStream());
//            byte[] bytes = out.toByteArray();
//            // 2、将字节数组转为二进制
//            BASE64Encoder encoder = new BASE64Encoder();
//            binary = encoder.encodeBuffer(bytes).trim();
        } catch (WriterException e) { 
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * image流数据处理
     *
     * @author ianly
     */
    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) ? 0xFF000000 : 0xFFFFFFFF);
            }
        }
        return image;
    }
}

1.后台生成二维码图片并保存图片

超链接以及js代码如下:

[<a href="#" onclick="showCode('<%=barcode%>')" class="unline">二维码</a>]

    //生成二维码方法
    function showCode(barcode){
        top.layer.open({
          type: 2,
          title:'',
          cancel: function(){ 
          
           },
          area: ['300px', '300px'],
          fixed: false, //不固定
          maxmin: false,
          Boolean: false,
         content: '<%=request.getContextPath()%>/frame/showCode.do?barcode='+barcode
        });
    }

后台生成二维码的代码:

/**
    * 生成二维码
     */
    public String showCode() {
        try {
            String barcode = request.getParameter("barcode");
            request.setAttribute("barcode", barcode);
            log.info("barcode-------------"+barcode);
            // 存放在二维码中的内容
            String text = "http://127.0.0.1:8080/扫描后需要调用的地址?barcode="+barcode;
            // 嵌入二维码的图片路径
            String imgPath = "D:/md5file/20191119181532.jpg";
            // 生成的二维码的路径及名称
            String destPath = "D:/md5file/"+barcode+".jpg";
            //生成二维码
            QRCodeUtil.encode(text, imgPath, destPath, true);
            // 解析二维码
            String str = QRCodeUtil.decode(destPath);
            // 打印出解析出的内容
            System.out.println(str);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "showCode";
    }

展示二维码的容器:

<!-- 存放二维码的容器 -->
<img src="二维码图片保存的地址"/>

2.页面实时生成二维码展示

超链接以及点击事件方法:

[<a href="#" onclick="showCode('<%=mywork.getFormcode()%>')" class="unline">二维码</a>]   

  //展示二维码 function showCode(barcode){ top.layer.open({ type: 2, title:'', cancel: function(){ }, area: ['300px', '300px'], fixed: false, //不固定 maxmin: false, Boolean: false, content: '<%=request.getContextPath()%>/jsp/frame/mywork/showCode.jsp?barcode='+barcode }); }

此处是点击超链接直接跳到弹框页面,在弹框页面上调后台生成二维码:

public void qrcode() {
        String barcode = request.getParameter("barcode");
        String content = 扫描二维码需要调用的后台地址?barcode="+barcode;
        //调用工具类,生成二维码   
        QRCodeUtil.creatRrCode(content, 300,300,response);   //300为图片高度和宽度
    }

弹框页面代码:

<%
    String barcode = request.getParameter("barcode");
    request.setAttribute("barcode", barcode);
%>
  <body>
      <input type="hidden" name="barcode" id="barcode"  value="${barcode}">
      <!-- 存放二维码的容器 -->
    <img src="<%=request.getContextPath()%>/frame/qrcode.do?barcode=${barcode}"/>
  </body>

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