大家好，又见面了，我是你们的朋友全栈君。如果您正在找激活码,请点击查看最新教程,关注关注公众号 “全栈程序员社区” 获取激活教程,可能之前旧版本教程已经失效.最新Idea2022.1教程亲测有效,一键激活。

Jetbrains全系列IDE使用 1年只要46元 售后保障 童叟无欺

前言

根据公司业务需求，需要将指定的url催缴二维码，于是有了以下总结，作为一个记录，以便以后可以用到哦！

一、将url直接生成二维码

package com.xiaojukeji.it.common.util;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.common.BitMatrix;

import javax.imageio.ImageIO;
import javax.swing.filechooser.FileSystemView;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

public class QrCodeUtil { 
   
    public static void main(String[] args) { 
   
        String url = "http://www.baidu.com";
        String path = FileSystemView.getFileSystemView().getHomeDirectory() + File.separator + "testQrcode";
        String fileName = "temp.jpg";
        createQrCode(url, path, fileName);
    }

    public static void createQrCode(String url,String path,String fileName) { 
   
        try { 
   
            Map<EncodeHintType, String> hints = new HashMap<>();
            hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
            BitMatrix bitMatrix = new MultiFormatWriter().encode(url, BarcodeFormat.QR_CODE, 400, 400, hints);
            File file = new File(path, fileName);
            if (file.exists() || ((file.getParentFile().exists() || file.getParentFile().mkdirs()) && file.createNewFile())) { 
   
                writeToFile(bitMatrix, "jpg", file);
                System.out.println("二维码图片：" + file);
            }
        } catch (Exception e) { 
   
            e.printStackTrace();
        }
    }

    static void writeToFile(BitMatrix matrix, String format, File file) throws IOException { 
   
        BufferedImage image = toBufferedImage(matrix);
        if (!ImageIO.write(image, format, file)) { 
   
            throw new IOException("Could not write an image of format " + format + " to " + file);
        }
    }

    private static final int BLACK = 0xFF000000;
    private static final int WHITE = 0xFFFFFFFF;

    private 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) ? BLACK : WHITE);
            }
        }
        return image;
    }
}

二、将url生成二维码并以base64返回

上面的方法只能够将url生成二维码，但是如果将此结果返回给前端的话，是无法直接展示的，因为前端需要接收一个base64的字符串，所以下面的方法诞生了

public static String methods(String str) { 
   
        MultiFormatWriter multiFormatWriter = new MultiFormatWriter();
        Map hints = new HashMap();
        hints.put(EncodeHintType.CHARACTER_SET, "UTF-8"); //设置字符集编码类型
        hints.put(EncodeHintType.MARGIN, 1); //设置白边
        BitMatrix bitMatrix = null;
        try { 
   
            bitMatrix = multiFormatWriter.encode(str, BarcodeFormat.QR_CODE, 300, 300, hints);
            BufferedImage image = toBufferedImage(bitMatrix);
            ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
//输出二维码图片流
            try { 
   
                ImageIO.write(image, "png", outputStream);
                return Base64.encodeBase64String(outputStream.toByteArray());
            } catch (IOException e) { 
   
                e.printStackTrace();
            }
        } catch (WriterException e1) { 
   
            e1.printStackTrace();
        }
        return null;
    }

    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);//0xFF000000黑；0xFFFFFFFF白
            }
        }
        return image;
    }

    public static void main(String[] args) { 
   
        String methods = methods("http://www.baidu.com"");
        System.out.println(methods);
    }

这样就大功告成啦！