1 @Controller   2 public class FileController implements ServletContextAware{    3     //Spring这里是通过实现ServletContextAware接口来注入ServletContext对象    4     private ServletContext servletContext;    5    6    7     @RequestMapping("file/download")    8     public void fileDownload(HttpServletResponse response){    9         //获取网站部署路径(通过ServletContext对象)，用于确定下载文件位置，从而实现下载   10         String path = servletContext.getRealPath("/");   11   　　　　response.rset();         //清楚空格等操作12         //1.设置文件ContentType类型，这样设置，会自动判断下载文件类型   13         response.setContentType("multipart/form-data");   14         //2.设置文件头：最后一个参数是设置下载文件名(假如我们叫a.pdf)   15         response.setHeader("Content-Disposition", "attachment;fileName="+"a.pdf");   16         ServletOutputStream out;   17         //通过文件路径获得File对象(假如此路径中有一个download.pdf文件)   18         File file = new File(path + "download/" + "download.pdf");   19   20         try {   21             FileInputStream inputStream = new FileInputStream(file);   22   23             //3.通过response获取ServletOutputStream对象(out)   24             out = response.getOutputStream();   25   26             int b = 0;   27             byte[] buffer = new byte[512];   28             while (b != -1){   29                 b = inputStream.read(buffer);   30                 //4.写到输出流(out)中   31                 out.write(buffer,0,b);   32             }   33             inputStream.close();   34             out.close();   35             out.flush();   36   37         } catch (IOException e) {   38             e.printStackTrace();   39         }   40     }   41   42     @Override  43     public void setServletContext(ServletContext servletContext) {   44         this.servletContext = servletContext;   45     }   46 }