记一次二维码在项目中的使用

最近项目用到了二维码，就学习整理了一下，二维码主要用到了zxing。框架使用的是SSM，另一篇博客有相关配置说明，如需了解请移步https://blog.csdn.net/w_q2018/article/details/102912420

Controller

package com.qrcode.controller;

import java.io.IOException;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;
import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;
import com.qrcode.bean.Bean;
import com.qrcode.service.Service;
import com.qrcode.util.MatrixToImageWriter;

@Controller
public class Controller {
	
    @Resource(name="Service")
    private Service service;

    @RequestMapping("download")
    public void download(HttpServletRequest request, HttpServletResponse response){
            //通过id查询
    	    List list = service.queryIdList();
            if(list != null && list.size()>0){
                ZipOutputStream zos = null;
                try {
                    String downloadFilename = "download";//文件的名称
                    downloadFilename = URLEncoder.encode(downloadFilename, "UTF-8");//转换中文否则可能会产生乱码
                    response.setContentType("application/octet-stream");// 指明response的返回对象是文件流 
                    response.setHeader("Content-Disposition", "attachment;filename=" + downloadFilename+".zip");// 设置在下载框默认显示的文件名
                    zos = new ZipOutputStream(response.getOutputStream());
                    for(Bean info:list ){
                        zos.putNextEntry(new ZipEntry(info.getId()+".png"));//命名
                        getBarCodeImgByUrl(info.getUrl()+info.getId(), zos);//拼接了url
                    }
                    zos.flush();     
                    zos.close();
                } catch (UnsupportedEncodingException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                } catch (WriterException e) {
                    e.printStackTrace();
                } finally{
                    if(zos != null){
                        try {
                            zos.flush();
                            zos.close();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }     

                    }

                }
            }
    }

    public static void getBarCodeImgByUrl(String url,OutputStream os) throws WriterException,IOException{
        //二维码参数
        int width = 400; // 图像宽度  
        int height = 400; // 图像高度  
        String format = "png";// 图像类型  
        Map hints = new HashMap();  
        hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");  
        BitMatrix bitMatrix;
        bitMatrix = new MultiFormatWriter().encode(url,BarcodeFormat.QR_CODE, width, height, hints);
        MatrixToImageWriter.writeToStream(bitMatrix, format, os);
    }
	
}

Service

package com.qrcode.service;

import java.util.List;

import javax.annotation.Resource;

import org.springframework.stereotype.Service;

import com.qrcode.bean.Bean;
import com.qrcode.dao.Dao;

@Service("Service ")
public class Service {
    @Resource
    private Dao dao;

    public List queryIdList(){
        return dao.queryIdList();
    }
}

 Dao

package com.qrcode.dao;

import java.util.List;

import com.qrcode.bean.Bean;

public interface Dao {
	public List queryIdList();
}

Bean

package com.qrcode.bean;

public class Bean {
	private long id;
	private String url;
	public long getId() {
		return id;
	}
	public void setId(long id) {
		this.id = id;
	}
	public String getUrl() {
		return url;
	}
	public void setUrl(String url) {
		this.url = url;
	}
	@Override
	public String toString() {
		return "Bean [id=" + id + ", url=" + url + "]";
	}
	
}

xml

	
		SELECT id,url FROM t_qrcode
	

 util

package com.qrcode.util;

import java.awt.image.BufferedImage;  

import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
 
import javax.imageio.ImageIO;
 
import java.util.Hashtable;
 
import com.google.zxing.common.BitMatrix;
import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;

public class MatrixToImageWriter {
    private static final int BLACK = 0xFF000000;
    private static final int WHITE = 0xFFFFFFFF;
 
    private MatrixToImageWriter() {
    }
 
    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) ? BLACK : WHITE);
            }
        }
        return image;
    }
 
    public 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);
        }
    }
 
    public static void writeToStream(BitMatrix matrix, String format,
            OutputStream stream) throws IOException {
        BufferedImage image = toBufferedImage(matrix);
        if (!ImageIO.write(image, format, stream)) {
            throw new IOException("Could not write an image of format " + format);
        }
    }
 
    public static void main(String[] args) throws Exception {
        String text = "http://www.baidu.com"; // 二维码内容
        int width = 300; // 二维码图片宽度
        int height = 300; // 二维码图片高度
        String format = "jpg";// 二维码的图片格式
 
        Hashtable hints = new Hashtable();
        hints.put(EncodeHintType.CHARACTER_SET, "utf-8"); // 内容所使用字符集编码
 
        BitMatrix bitMatrix = new MultiFormatWriter().encode(text,
                BarcodeFormat.QR_CODE, width, height, hints);
        // 生成二维码
        File outputFile = new File("d:" + File.separator + "new.jpg");
        MatrixToImageWriter.writeToFile(bitMatrix, format, outputFile);
    }
}