文件批量下载

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 java下载多个文件，可以先把多个文件打包压缩成  zip 文件，然后下载zip文件

 代码如下：

       /**
	 * 生成zip
	 * @param sourcePath 原文件夹路径
	 * @param zipPath 生成的zip路径
	 */
	public static void createZip(String sourcePath, String zipPath) {
	    FileOutputStream fos = null;
	    ZipOutputStream zos = null;
	    try {
	        fos = new FileOutputStream(zipPath);
	        zos = new ZipOutputStream(fos);
	        writeZip(new File(sourcePath), "", zos);
	    } catch (FileNotFoundException e) {
	        e.printStackTrace();
	    } finally {
	        try {
	            if (zos != null) {
	                zos.close();
	            }
	        } catch (IOException e) {
	        	 e.printStackTrace();
	        }
	    }
	}
	private static void writeZip(File file, String parentPath, ZipOutputStream zos) {
	    if(file.exists()){
	        if(file.isDirectory()){//处理文件夹
	            parentPath+=file.getName()+File.separator;
	            File [] files=file.listFiles();
	            for(File f:files){
	                writeZip(f, parentPath, zos);
	            }
	        }else{
	            FileInputStream fis=null;
	            DataInputStream dis=null;
	            try {
	                fis=new FileInputStream(file);
	                dis=new DataInputStream(new BufferedInputStream(fis));
	                ZipEntry ze = new ZipEntry(parentPath + file.getName());
	                zos.putNextEntry(ze);
	                zos.setEncoding("GBK");
	                byte [] content=new byte[1024];
	                int len;
	                while((len=fis.read(content))!=-1){
	                    zos.write(content,0,len);
	                    zos.flush();
	                }
	                 
	             
	            } catch (FileNotFoundException e) {
	                e.printStackTrace();
	            } catch (IOException e) {
	            	e.printStackTrace();
	            }finally{
	                try {
	                    if(dis!=null){
	                        dis.close();
	                    }
	                }catch(IOException e){
	                	e.printStackTrace();
	                }
	            }
	        }
	    }
	}

 

 调用方法：

.createZip(FilePath+fileNameAll, FilePath+fileNameAll+".zip");

 接下来就是下载：

 

       /**
	 * 下载公共方法
	 * @param response
	 * @param str 下载的文件名
	 */
	 private void downFile(HttpServletResponse response, HttpServletRequest request,String str) {   
	        try {   
	        	String FilePath = request.getSession().getServletContext().getRealPath(File.separator);
	            String path = FilePath + str;   
	            File file = new File(path);   
	            if (file.exists()) {   
	                InputStream ins = new FileInputStream(path);   
	                BufferedInputStream bins = new BufferedInputStream(ins);// 放到缓冲流里面   
	                OutputStream outs = response.getOutputStream();// 获取文件输出IO流   
	                BufferedOutputStream bouts = new BufferedOutputStream(outs);   
	                response.setContentType("application/x-download");// 设置response内容的类型   
	                response.setHeader(   
	                        "Content-disposition",   
	                        "attachment;filename="  
	                                + URLEncoder.encode(str, "UTF-8"));// 设置头部信息   
	                int bytesRead = 0;   
	                byte[] buffer = new byte[8192];   
	                // 开始向网络传输文件流   
	                while ((bytesRead = bins.read(buffer, 0, 8192)) != -1) {   
	                    bouts.write(buffer, 0, bytesRead);   
	                }   
	                bouts.flush();// 这里一定要调用flush()方法   
	                ins.close();   
	                bins.close();   
	                outs.close();   
	                bouts.close();  
	            } else {   
	                
	            }   
	        } catch (IOException e) {   
	            
	        }   
	    }