File - 浏览器文件下载的两种方式

通过流进行下载（弊端：不可关闭连接或跳转页面）

public void saveBatchDownloadFile(String taskNumber, HttpServletResponse response){
       
        BufferedInputStream bufferStream = null;
        
        ServletOutputStream outputStream = null;
        
        File file = new File(taskNumber + ".zip");
        
        try {
        
            FileInputStream fileInputStream = new FileInputStream(file);
            
            outputStream = response.getOutputStream();
            
            bufferStream = new BufferedInputStream(fileInputStream, 1024 * 10);
            
            int read = 0;
            
            byte[] buf = new byte[1024 * 10];
            
            while((read = bufferStream.read(buf, 0, 1024 * 10)) != -1){
            
                outputStream.write(buf, 0, read);
                
            }
            
        } catch (Exception e) {
        
            log.error("文件下载异常信息:{}", e);
            
        }finally {
        
            try {
            
                outputStream.flush();
                
                outputStream.close();
                
                bufferStream.close();
                
            } catch (IOException e) {
            
                e.printStackTrace();
                
            }
            
        }
        
        file.delete();
        
    }

}

浏览器强制下载（优点：可关闭链接或跳转页面，将下载任务交给浏览器）

public void saveBatchDownloadFile(String taskNumber, HttpServletResponse response){
       
        BufferedInputStream bufferStream = null;
        
        ServletOutputStream outputStream = null;
        
        File file = new File(taskNumber + ".zip");
        
        try {
        
            response.reset();
            
            String currentDate = DateUtil.getCurrentDateYMD();
            
            response.setCharacterEncoding("utf-8");
            
            response.setContentType("multipart/form-data");
            
            response.setContentLengthLong(file.length());
            
            // 使浏览器下载
            
            String name = currentDate +"-协议文件.zip";
            
            String fileName = new String(name.getBytes("utf-8"),"ISO-8859-1");
            
            response.setHeader("Content-Disposition", "attachment;filename=" + fileName);
            
            FileInputStream fileInputStream = new FileInputStream(file);
            
            outputStream = response.getOutputStream();
            
            bufferStream = new BufferedInputStream(fileInputStream);
            
            int read = 0;
            
            byte[] buf = new byte[100];
            
            while((read = bufferStream.read(buf)) != -1){
            
                outputStream.write(buf, 0, read);
                
            }
            
        } catch (Exception e) {
        
            log.error("文件下载异常信息:{}", e);
            
            return;
            
        }finally {
        
            try {
            
                bufferStream.close();
                
            } catch (IOException e) {
            
                e.printStackTrace();
                
            }
            
        }
        
        file.delete();
        
    }
    
}