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你知道生成二维码的url有长度限制么

全栈的程序员 2022-04-28
730

因为工作的原因好久没有更新了,今天更新一个在项目中遇到的问题。



因为一个需求需要根据url生成二维码放在宣传海报上,换言之就是生成活动海报。但是总会遇到url超长的活动地址,一开始生成的二维码有的识别不了,还以为生成二维码的方法有问题,结果是url过长了。



查阅资料如下,大家一起长见识一下。

二维码信息容量大:可容纳多达1850个大写字母或2710个数字或1108个字节,或500多个汉字。或者大家见到格外长的就是有问题,平时遇到的都没事,因为都是短链



只说问题太枯燥了,下面分享java生成二维码的工具类


    package com.ai.wesmall.utils;


    import com.google.zxing.BarcodeFormat;
    import com.google.zxing.EncodeHintType;
    import com.google.zxing.MultiFormatWriter;
    import com.google.zxing.common.BitMatrix;
    import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
    import javax.imageio.ImageIO;
    import java.awt.*;
    import java.awt.image.BufferedImage;
    import java.io.File;
    import java.util.*;
    import com.google.zxing.*;
    import com.google.zxing.client.j2se.BufferedImageLuminanceSource;
    import com.google.zxing.common.HybridBinarizer;
    import org.springframework.util.ResourceUtils;


    import java.awt.geom.RoundRectangle2D;
    import java.io.OutputStream;
    import java.util.Hashtable;


    /**
    * ClassName QrCodeUtils
    */
    public class QrCodeUtils {




    private static final String CHARSET = "utf-8";
    private static final String FORMAT = "JPG";
    // 二维码尺寸
    private static final int QRCODE_SIZE = 300;
    // LOGO宽度
    private static final int LOGO_WIDTH = 60;
    // LOGO高度
    private static final int LOGO_HEIGHT = 60;


    public static BufferedImage createImage(String content, String logoPath, 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, 0);
    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 (logoPath == null || "".equals(logoPath)) {
    return image;
    }
    // 插入图片
    QrCodeUtils.insertImage(image, logoPath, needCompress);
    return image;
    }


    /**
    * 插入LOGO
    *
    * @param source 二维码图片
    * @param logoPath LOGO图片地址
    * @param needCompress 是否压缩
    * @throws Exception
    */
    private static void insertImage(BufferedImage source, String logoPath, boolean needCompress) throws Exception {
    System.out.println("logoPath::::::::::"+logoPath);
    System.out.println("source::::::::::"+source);


    File file = ResourceUtils.getFile(logoPath);
    if (!file.exists()) {
    throw new Exception("logo file not found.");
    }
    Image src = ImageIO.read(new File(logoPath));
    int width = src.getWidth(null);
    int height = src.getHeight(null);
    if (needCompress) { // 压缩LOGO
    if (width > LOGO_WIDTH) {
    width = LOGO_WIDTH;
    }
    if (height > LOGO_HEIGHT) {
    height = LOGO_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)
    * 二维码文件名随机,文件名可能会有重复
    *
    * @param content 内容
    * @param logoPath 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 logoPath, String destPath, boolean needCompress) throws Exception {
    BufferedImage image = QrCodeUtils.createImage(content, logoPath, needCompress);
    mkdirs(destPath);
    String fileName = new Random().nextInt(99999999) + "." + FORMAT.toLowerCase();
    ImageIO.write(image, FORMAT, new File(destPath + "/" + fileName));
    return fileName;
    }


    /**
    * 生成二维码(内嵌LOGO)
    * 调用者指定二维码文件名
    *
    * @param content 内容
    * @param logoPath LOGO地址
    * @param destPath 存放目录
    * @param fileName 二维码文件名
    * @param needCompress 是否压缩LOGO
    * @throws Exception
    */
    public static String encode(String content, String logoPath, String destPath, String fileName, boolean needCompress) throws Exception {
    BufferedImage image = QrCodeUtils.createImage(content, logoPath, needCompress);
    fileName = fileName.substring(0, fileName.indexOf(".") > 0 ? fileName.indexOf(".") : fileName.length())
    + "." + FORMAT.toLowerCase();
    ImageIO.write(image, FORMAT, new File(destPath + "/" + fileName));
    //自己的文件服务器地址
    return "https://om.51186.com.cn/cloudShopPC"+destPath + "/" + fileName;
    }


    /**
    * 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)
    *
    * @param destPath 存放目录
    */
    public static void mkdirs(String destPath) {
    File file = new File(destPath);
    if (!file.exists() && !file.isDirectory()) {
    file.mkdirs();
    }
    }


    /**
    * 生成二维码(内嵌LOGO)
    *
    * @param content 内容
    * @param logoPath LOGO地址
    * @param destPath 存储地址
    * @throws Exception
    */
    public static String encode(String content, String logoPath, String destPath) throws Exception {
    return QrCodeUtils.encode(content, logoPath, 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 String encode(String content, String destPath, boolean needCompress) throws Exception {
    return 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 String encode(String content, String destPath) throws Exception {
    return QrCodeUtils.encode(content, null, destPath, false);
    }


    /**
    * 生成二维码(内嵌LOGO)
    *
    * @param content 内容
    * @param logoPath LOGO地址
    * @param output 输出流
    * @param needCompress 是否压缩LOGO
    * @throws Exception
    */
    public static void encode(String content, String logoPath, OutputStream output, boolean needCompress)
    throws Exception {
    BufferedImage image = QrCodeUtils.createImage(content, logoPath, needCompress);
    ImageIO.write(image, FORMAT, 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 qrUrl = "https://www.baidu.com";
    //不含Logo
    //QrCodeUtils.encode(text, null, "/Users/ianly/Documents/picture", true);
    //含Logo,不指定二维码图片名
    //QrCodeUtils.encode(text, "/Users/ianly/Documents/picture/google-icon.jpg", "/Users/ianly/Documents/picture/", true);
    //含Logo,指定二维码图片名
    String logoPath="C:\\Users\\Administrator\\Desktop\\666.png";
    String fileName = UUID.randomUUID().toString();
    String encode = QrCodeUtils.encode(qrUrl, logoPath, "E:\\app", fileName, true);
    System.out.println(encode);
    }




    }
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