二维码生成(QRcode)

二维码生成(QRcode)

<!-- https://mvnrepository.com/artifact/com.google.zxing/core -->
<dependency>
      <groupId>com.google.zxing</groupId>
      <artifactId>core</artifactId>
      <version>3.5.0</version>
    </dependency>
    <dependency>
      <groupId>com.google.zxing</groupId>
      <artifactId>javase</artifactId>
      <version>3.5.0</version>
</dependency>

官网:https://mvnrepository.com/artifact/com.google.zxing/core/3.5.0

import com.google.zxing.*;
import com.google.zxing.client.j2se.BufferedImageLuminanceSource;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.common.HybridBinarizer;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.geom.RoundRectangle2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.OutputStream;
import java.util.Hashtable;
import java.util.Random;

public class QRCodeUtils {
    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<EncodeHintType, Object> hints = new Hashtable<EncodeHintType, Object>();
        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
        QRCodeUtils.insertImage(image, imgPath, needCompress);
        return image;
    }

    /**
     * 插入LOGO
     *
     * @param source
     *            二维码图片
     * @param imgPath
     *            LOGO图片地址
     * @param needCompress
     *            是否压缩
     * @throws Exception
     */
    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();
    }

    /**
     * 生成二维码(内嵌LOGO)
     *
     * @param content
     *            内容
     * @param imgPath
     *            LOGO地址
     * @param destPath
     *            存放目录
     * @param needCompress
     *            是否压缩LOGO
     * @throws Exception
     */
    public static String encode(String content, String imgPath, String destPath,
                                boolean needCompress) throws Exception {
        BufferedImage image = QRCodeUtils.createImage(content, imgPath,
                needCompress);
        mkdirs(destPath);
        String file = new Random().nextInt(99999999)+".jpg";
        ImageIO.write(image, FORMAT_NAME, new File(destPath+"/"+file));
        return file;
    }

    /**
     * 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)
     * @date 2013-12-11 上午10:16:36
     * @param destPath 存放目录
     */
    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();
        }
    }

    /**
     * 生成二维码(内嵌LOGO)
     *
     * @param content
     *            内容
     * @param imgPath
     *            LOGO地址
     * @param destPath
     *            存储地址
     * @throws Exception
     */
    public static void encode(String content, String imgPath, String destPath)
            throws Exception {
        QRCodeUtils.encode(content, imgPath, destPath, false);
    }

    /**
     * 生成二维码
     *
     * @param content
     *            内容
     * @param destPath
     *            存储地址
     * @param needCompress
     *            是否压缩LOGO
     * @throws Exception
     */
    public static void encode(String content, String destPath,
                              boolean needCompress) throws Exception {
        QRCodeUtils.encode(content, null, destPath, needCompress);
    }

    /**
     * 生成二维码
     *
     * @param content
     *            内容
     * @param destPath
     *            存储地址
     * @throws Exception
     */
    public static void encode(String content, String destPath) throws Exception {
        QRCodeUtils.encode(content, null, destPath, false);
    }

    /**
     * 生成二维码(内嵌LOGO)
     *
     * @param content
     *            内容
     * @param imgPath
     *            LOGO地址
     * @param output
     *            输出流
     * @param needCompress
     *            是否压缩LOGO
     * @throws Exception
     */
    public static void encode(String content, String imgPath,OutputStream output, boolean needCompress) throws Exception {
        BufferedImage image = QRCodeUtils.createImage(content, imgPath,needCompress);
        ImageIO.write(image, FORMAT_NAME, output);
    }

    /**
     * 生成二维码
     *
     * @param content
     *            内容
     * @param output
     *            输出流
     * @throws Exception
     */
    public static void encode(String content, OutputStream output)  throws Exception {
        QRCodeUtils.encode(content, null, output, false);
    }

    /**
     * 解析二维码
     *
     * @param file
     *            二维码图片
     * @return
     * @throws Exception
     */
    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<DecodeHintType, Object> hints = new Hashtable<DecodeHintType, Object>();
        hints.put(DecodeHintType.CHARACTER_SET, CHARSET);
        result = new MultiFormatReader().decode(bitmap, hints);
        String resultStr = result.getText();
        return resultStr;
    }

    /**
     * 解析二维码
     *
     * @param path
     *            二维码图片地址
     * @return
     * @throws Exception
     */
    public static String decode(String path) throws Exception {
        return QRCodeUtils.decode(new File(path));
    }

    public static void main(String[] args) throws Exception {
        String text = "http://www.baidu.com";  //这里设置自定义网站url
        String logoPath = "C:\\Users\\admin\\Desktop\\test\\test.jpg";
        String destPath = "C:\\Users\\admin\\Desktop\\test\\";
        System.out.println(QRCodeUtils.encode(text, logoPath, destPath, true));
    }
}

乱码解决方法

在前端添加指定编码utf-8
<meta charset="utf-8">
在后端添加指定编码utf-8
req.setCharacterEncoding("utf-8");
resp.setCharacterEncoding("utf-8");

可以实现前端GBK后端UTF-8(已废弃)

那么可以在页面get提交时对中文进行url转码,后台进行解码即可。

前台页面:

var str=encodeURI(encodeURI(“这里是要加密的含有中文的字符串”));

为什么这里要加密两次呢?

答案是因为第一次加密,生成了含有%开头的字符串,但是在浏览器里面%是一个转义字符,在浏览器提交到服务器时会将这一串加密后的字符串%与%之间的编码,两位两位取出后进行解码,然后再传递给处理页面,所以加密一次不够,加密两次以后后台拿到的才是正确加密过的字符串,才能进行解码的操作!

后台页面:

String result= URLDecoder.decode(request.getParameter(“取到的加密字符串”), “utf-8”);
https://www.yuque.com/docs/share/cc451c95-9302-4609-a666-03b97fcbf4d8?# 《关于get方式提交中文乱码问题的解决方式》