多文件下載--壓縮包,實現邊下載邊導出

原文地址:https://www.jianshu.com/p/7cabe09ce563

親測有效,很好用!

public void downloadFiles(HttpServletRequest request, HttpServletResponse response, 其他爲獲取下載文件信息的必須參數){
        
        //響應頭的設置
        response.reset();
        response.setCharacterEncoding("utf-8");
        response.setContentType("multipart/form-data");
        
        //設置壓縮包的名字
         //解決不同瀏覽器壓縮包名字含有中文時亂碼的問題
        String downloadName = "我是壓縮包的名字.zip";
        String agent = request.getHeader("USER-AGENT");   
        try {
            if (agent.contains("MSIE")||agent.contains("Trident")) {
                downloadName = java.net.URLEncoder.encode(downloadName, "UTF-8");
            } else {
                downloadName = new String(downloadName.getBytes("UTF-8"),"ISO-8859-1");
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        response.setHeader("Content-Disposition", "attachment;fileName=\"" + downloadName + "\"");
        
        //設置壓縮流：直接寫入response，實現邊壓縮邊下載
        ZipOutputStream zipos = null;
        try {
            zipos = new ZipOutputStream(new BufferedOutputStream(response.getOutputStream()));
            zipos.setMethod(ZipOutputStream.DEFLATED); //設置壓縮方法 
        } catch (Exception e) {
            e.printStackTrace();
        }
        
        //循環將文件寫入壓縮流
        DataOutputStream os = null;
        for(int i = 0; i < 要下載的文件個數; i++ ){
            
            File file = new File(要下載的某個文件的路徑);
            try {
                //添加ZipEntry，並ZipEntry中寫入文件流
                //這裏，加上i是防止要下載的文件有重名的導致下載失敗
                zipos.putNextEntry(new ZipEntry(i + 文件名字));
                os = new DataOutputStream(zipos);
                InputStream is = new FileInputStream(file);
                byte[] b = new byte[100];
                int length = 0;
                while((length = is.read(b))!= -1){
                    os.write(b, 0, length);
                }
                is.close();
                zipos.closeEntry();
            } catch (IOException e) {
                e.printStackTrace();
            } 
        }
        
        //關閉流
        try {
            os.flush();
            os.close();
            zipos.close();
        } catch (IOException e) {
            e.printStackTrace();
        }   
        
    }