SpringMVC的文件上传形式
@Controller
public class UploadController {
 /*
  * 单个文件上传
  */
 @RequestMapping("/uploadFile")//
 public <HttpServletRequest> String uploadFile(@RequestParam("file")MultipartFile multipartFile,javax.servlet.http.HttpServletRequest request){
  System.out.println("UploadController.uploadFile()");
  System.out.println(multipartFile.getOriginalFilename());
  //上传文件的路径
  String uploadPath="D:/eclipse/eclipsedata/SpringMVC_4_upload/WebContent/upload";
//  String uploadpaht = request.getSession().getServletContext().getRealPath("upload");
  try {
   FileCopyUtils.copy(multipartFile.getInputStream(), new FileOutputStream(uploadPath+File.separatorChar+multipartFile.getOriginalFilename()));
  } catch (FileNotFoundException e) {
   e.printStackTrace();
  } catch (IOException e) {
   e.printStackTrace();
  }
  return "/ok"; 
 }
  // 多个文件上传
 
 @RequestMapping("/uploadFile2")//
 public <HttpServletRequest> String uploadFile2(@RequestParam("file")MultipartFile[] multipartFile,javax.servlet.http.HttpServletRequest request){
  System.out.println("UploadController.uploadFile()");
//  System.out.println(multipartFile[].getOriginalFilename());
  //上传文件的路径
  String uploadPath="D:/eclipse/eclipsedata/SpringMVC_4_upload/WebContent/upload";
  //String uploadpaht = request.getServletContext().getRealPath("upload");
  for (int i = 0; i < multipartFile.length; i++) {
   try {
    //工具类进行拷贝
    FileCopyUtils.copy(multipartFile[i].getInputStream(), new FileOutputStream(uploadPath+File.separatorChar+multipartFile[i].getOriginalFilename()));
    System.out.println(multipartFile[i].getOriginalFilename());//输出文件的名字
   } catch (FileNotFoundException e) {
    e.printStackTrace();
   } catch (IOException e) {
    e.printStackTrace();
   }
  }
  return "/ok";
 }
}
文件下载
@Controller
public class DownLoadController {
 @RequestMapping("/download")
 public void download(HttpServletRequest request,HttpServletResponse response){
  //定义文件下载路径
  String downPath="D:/aaa/SpringMVC_4_downLoad/WebContent/upload/d.jpg";
  //配置响应头文件
  String fileName="索隆.png";
  response.setContentType("application/x-msdownload");
  try {
   response.setHeader("Content-Disposition", "attachment;filename=" +new String(fileName.getBytes("utf-8"),"iso-8859-1"));
  } catch (UnsupportedEncodingException e1) {

   e1.printStackTrace();
  }
  //读取文件
  try {
   FileInputStream iStream=new FileInputStream(downPath);
   
   FileCopyUtils.copy(iStream, response.getOutputStream());
  } catch (FileNotFoundException e) {
   e.printStackTrace();
  } catch (IOException e) {
   e.printStackTrace();
  }
 }
}

Struts2中文件上传下载的方式；
上传单个文件的代码
public class FileUpload extends ActionSupport {
 private File file;
 private String fileFileName;//定义文件名字，struts会对文件自动赋值
 private String fileContentType;
 public String execute(){
  System.out.println("FileUpload.execute()");
//  System.out.println(file);
  String uploadPath="D:/movie/upload/";//文件上传的路径
  String fileName="a.jpg";
  //FileUtils.copyDirectory(srcDir, destDir);src:源文件路径,dest:目标文件路径
  try {
   FileUtils.copyFile(file, new File(uploadPath+fileFileName));
  } catch (IOException e) {
   e.printStackTrace();
  }
  return Action.SUCCESS;  }
 public File getFile() {
  return file;
 }
 public void setFile(File file) {
  this.file = file;
 }
 public String getFileFileName() {
  return fileFileName;
 }
 public void setFileFileName(String fileFileName) {
  this.fileFileName = fileFileName;
 }
 public String getFileContentType() {
  return fileContentType;
 }
 public void setFileContentType(String fileContentType) {
  this.fileContentType = fileContentType;
 }
}
上传的Jsp是：
<s:form action="upload" method="post" enctype="multipart/form-data">
  <s:file name ="file" label="上传文件"/>
  <s:file name ="file" label="上传文件"/>
  <s:submit value="上传"/>
</s:form>
 

上传多个文件
public class FileUpload2 extends ActionSupport {
 private File[] file;
 private String[] fileFileName;
 private String fileContextType;
 public String execute(){
  System.out.println("FileUpload2.execute()");
  String uploadPath="D:/movie/upload/";
   try {
    for(int i=0;i<file.length;i++){
    FileUtils.copyFile(file[i], new File(uploadPath+getFileFileName()[i])); 
    }
   } catch (IOException e) {
    e.printStackTrace();
   }
   return Action.SUCCESS;
  }
 public String[] getFileFileName() {
  return fileFileName;
 }
 public void setFileFileName(String[] fileFileName) {
  this.fileFileName = fileFileName;
 }
 public String getFileContextType() {
  return fileContextType;
 }
 public void setFileContextType(String fileContextType) {
  this.fileContextType = fileContextType;
 }
 public File[] getFile() {
  return file;
 }
 public void setFile(File[] file) {
  this.file = file;
 }
 
}

下载文件
public class FileDownLoad {
 private InputStream ips;//构建下载文件的输入流
 private String fileName;
 public String execute(){
  System.out.println("FileDownLoad.execute()");
  //设置下载文件路径
  String downFile="D:/movie/a.txt";
  try {
   ips=new FileInputStream(new File(downFile));
   fileName="a.txt";//下载后文件名称
  } catch (FileNotFoundException e) {
   e.printStackTrace();
  }
  return Action.SUCCESS;
 }
 public InputStream getIps() {
  return ips;
 }
 public void setIps(InputStream ips) {
  this.ips = ips;
 }
 public String getFileName() {
  return fileName;
 }
 public void setFileName(String fileName) {
  this.fileName = fileName;
 }
}