最近公司有个需求，需要点击一个按钮生成二维码，然后把二维码打包成zip文件，然后下载zip文件，于是我做了个demo，这里分享一下。
文件下载不能异步请求，因为我需要url后面动态拼接参数，所以这里用了button,具体前台代码如下可以实现下载（看压缩文件下载就可以了）：
<body>
<input type="button" name="按钮啊" id="zipButton" value="压缩文件下载">
<input type="button" name="按钮" id="button" value="按钮">
<a href="/downLoadServlet">下载</a>
<script src="js/jquery-3.3.1.min.js"></script>
<script>
$("#button").click(function () {
window.location.href = "/downLoadServlet?templateId=111111";
});
$("#zipButton").click(function () {
window.location.href = "/zipDownLoadServlet";
})
</script>
</body>
后台主要分为这几个步骤：1生成二维码，2生成zip文件，3zip文件输出到输出流，4删除生成的文件。具体代码如下：
package com.mr.smart;
import com.google.zxing.WriterException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.net.URLEncoder;
import java.util.Arrays;
import java.util.List;
@WebServlet(name = "ZipDownLoadServlet", value = "/zipDownLoadServlet")
public class ZipDownLoadServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String realPath = request.getSession().getServletContext().getRealPath("/");
//1 生成二维码
String projectName = "农银公杂费";
String path = realPath + projectName;
File file = new File(path);
if (!file.exists()) {
file.mkdirs();
}
List<String> list = Arrays.asList("code11.jpg", "code22.jpg", "code33.jpg");//已经存好的图片
try {
for (String x : list) {
String source = "G://" + x;
String qrCode = path + "/公杂费_" + x;
String url = "https://www.baidu.com/?name=" + x;
QRCodeUtil.generateQRImage(url, qrCode, source);//生成二维码的方法
}
} catch (WriterException e) {
e.printStackTrace();
}
//2 生成zip文件
ZipHelper.zipCompress(path, path + ".zip");
//3 下载
String zipFileName = path + ".zip";
String filename = projectName + ".zip";
//设置文件MIME类型
response.setContentType(getServletContext().getMimeType(filename));
response.setCharacterEncoding("UTF-8");
//设置Content-Disposition
response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(filename, "utf-8"));
InputStream in = new FileInputStream(zipFileName);
OutputStream out = response.getOutputStream();
//写文件
int b;
while ((b = in.read()) != -1) {
out.write(b);
}
out.flush();
//4 删除多余文件
deleteDir(new File(path));
in.close();//先关闭输入流才能删除
deleteDir(new File(zipFileName));
out.close();
}
private boolean deleteDir(File dir) {
if (dir.isDirectory()) {
String[] children = dir.list();
for (String s : children) {
boolean success = deleteDir(new File(dir, s));
if (!success) {
return false;
}
}
}
// 目录此时为空，可以删除
return dir.delete();
}
}
中间用到了生成二维码的工具类，生成zip文件的工具类，具体代码见:https://github.com/zhanxupeng/DownLoadTest/
