java下载文件夹（其实是下载压缩文件zip）

超、凢脫俗 2023-06-11 11:27 8阅读 0赞

推荐必看：[https://blog.csdn.net/persistencegoing/article/details/84376427][https_blog.csdn.net_persistencegoing_article_details_84376427]

第一步把多个文件夹生成压缩文件

package com.shutang.util;
    
    import java.io.*;
    import java.util.ArrayList;
    import java.util.List;
    import java.util.zip.CRC32;
    import java.util.zip.CheckedOutputStream;
    import java.util.zip.ZipEntry;
    import java.util.zip.ZipOutputStream;
    
    /**
     * 压缩类
     * @author xrj
     * @date 2019/10/31
     */
    public class ZipCompressor {
    
        static final int BUFFER = 8192;
    
        /**
         * 压缩的文件夹
         */
        private File zipFile;
    
        public ZipCompressor(String pathName) {
            zipFile = new File(pathName);
        }
    
    
        /**
         * 遍历需要压缩文件集合
         * @param pathName
         * @throws IOException
         */
        public void compress(String... pathName) throws IOException {
            ZipOutputStream out =null;
            FileOutputStream fileOutputStream=null;
            CheckedOutputStream cos=null;
            try {
                fileOutputStream = new FileOutputStream(zipFile);
                cos = new CheckedOutputStream(fileOutputStream,new CRC32());
                out = new ZipOutputStream(cos);
                String basedir = "";
                for (int i=0;i<pathName.length;i++){
                    compress(new File(pathName[i]), out, basedir);
                }
            } catch (Exception e) {
                throw new RuntimeException(e);
            }finally {
                if(out!=null){
                    out.close();
                }
                if(fileOutputStream!=null){
                    fileOutputStream.close();
                }
                if(cos!=null){
                    cos.close();
                }
            }
        }
    
    
        /**
         * 压缩
         * @param file
         * @param out
         * @param basedir
         */
        private void compress(File file, ZipOutputStream out, String basedir) throws IOException {
            // 判断是目录还是文件
            if (file.isDirectory()) {
                this.compressDirectory(file, out, basedir);
            } else {
                this.compressFile(file, out, basedir);
            }
        }
    
        /**
         * 压缩一个目录
         * */
        private void compressDirectory(File dir, ZipOutputStream out, String basedir) throws IOException {
            if (!dir.exists()){
                return;
            }
            File[] files = dir.listFiles();
            for (int i = 0; i < files.length; i++) {
                // 递归
                compress(files[i], out, basedir + dir.getName() + "/");
            }
        }
    
        /**
         * 压缩一个文件
         *
         * */
        private void compressFile(File file, ZipOutputStream out, String basedir) throws IOException {
            if (!file.exists()) {
                return;
            }
            BufferedInputStream bis =null;
            try {
                bis = new BufferedInputStream(new FileInputStream(file));
                ZipEntry entry = new ZipEntry(basedir + file.getName());
                out.putNextEntry(entry);
                int count;
                byte[] data = new byte[BUFFER];
                while ((count = bis.read(data, 0, BUFFER)) != -1) {
                    out.write(data, 0, count);
                }
            } catch (Exception e) {
                throw new RuntimeException(e);
            }finally {
                if(bis!=null){
                    bis.close();
                }
            }
        }
    
    
        /**
         * 生成压缩文件
         * @param args
         * @throws IOException
         */
        public static void main(String[] args) throws IOException {
            //压缩文件生成的路径
            ZipCompressor zc = new ZipCompressor("D:/CloudMusic/resource.zip");
            List<String> list=new ArrayList<>();
            //随便新建几个文件
            list.add("D:/CloudMusic/1.doc");
            list.add("D:/CloudMusic/2.xls");
            list.add("D:/CloudMusic/3.txt");
            //图片文件夹
            list.add("D:/CloudMusic/img/");
            String[] strings = new String[list.size()];
            list.toArray(strings);
            zc.compress(strings);
        }
    
    
    }

第二步    工具类zip下载方法

/**
     * 下载压缩包
     * @param file
     * @param response
     * @return
     */
    public static HttpServletResponse downloadZip(File file,HttpServletResponse response) {
        InputStream fis = null;
        OutputStream toClient = null;
        try {
            // 以流的形式下载文件。
             fis = new BufferedInputStream(new FileInputStream(file.getPath()));
            byte[] buffer = new byte[fis.available()];
            fis.read(buffer);
            // 清空response
            response.reset();
             toClient = new BufferedOutputStream(response.getOutputStream());
            response.setContentType("application/octet-stream");
    
            //如果输出的是中文名的文件，在此处就要用URLEncoder.encode方法进行处理
            response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(file.getName(), "UTF-8"));
            toClient.write(buffer);
            toClient.flush();
        } catch (IOException ex) {
            ex.printStackTrace();
        }finally{
            try {
                File f = new File(file.getPath());
                f.delete();
               if(fis!=null){
                   fis.close();
               }
               if(toClient!=null){
                   toClient.close();
               }
    
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return response;
    }

第三步controller调用

/**
     *  下载
     * @return
     */
    @RequestMapping(value = "/down.do")
    public void down(HttpServletResponse response){

String name="D:/CloudMusic/"+System.currentTimeMillis()+".zip";
    ZipCompressor zc = new ZipCompressor(name);
    List<String> list=new ArrayList<>();
    list.add("D:/CloudMusic/1.doc");
    list.add("D:/CloudMusic/2.xls");
    list.add("D:/CloudMusic/3.txt");
    list.add("D:/CloudMusic/img/");
    String[] strings = new String[list.size()];
    list.toArray(strings);
    File file=null;
    try {
       zc.compress(strings);
       file=new File(name);
       LoadUtils.downloadZip(file,response);
    } catch (IOException e) {
       e.printStackTrace();
    }finally {
       if(file!=null){
          file.delete();
       }
    }

}

工作中使用的话，压缩文件名用时间戳，用完记得删除本地文件。

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[https_blog.csdn.net_persistencegoing_article_details_84376427]: https://blog.csdn.net/persistencegoing/article/details/84376427