package com.emerson.cwms.utils; 
 
import java.io.File; 
import java.io.FileInputStream; 
import java.io.FileNotFoundException; 
import java.io.FileOutputStream; 
import java.io.IOException; 
import java.io.InputStream; 
import java.io.OutputStream; 
import java.util.Date; 
import java.util.HashMap; 
import java.util.Iterator; 
import java.util.Map; 
import java.util.Map.Entry; 
 
import org.springframework.web.multipart.MultipartFile; 
 
/** 
 * 文件上传工具类 
 * 
 * @author Chris Mao(Zibing) 
 * 
 */ 
public class FileUploadingUtil { 
 
  /** 
   * 服务器上的保存路径，在使用到上传功能的Controller中对其进行赋值 
   */ 
  public static String FILEDIR = null; 
 
  /** 
   * 上传多个文件，返回文件名称和服务器存储路径列表 
   * 
   * @param files 
   * @return 
   * @throws IOException 
   */ 
  public static Map<String, String> upload(Map<String, MultipartFile> files) throws IOException { 
    File file = new File(FILEDIR); 
    if (!file.exists()) { 
      file.mkdir(); 
    } 
 
    Map<String, String> result = new HashMap<String, String>(); 
    Iterator<Entry<String, MultipartFile>> iter = files.entrySet().iterator(); 
    while (iter.hasNext()) { 
      MultipartFile aFile = iter.next().getValue(); 
      if (aFile.getSize() != 0 && !"".equals(aFile.getName())) { 
        result.put(aFile.getOriginalFilename(), uploadFile(aFile)); 
      } 
    } 
    return result; 
  } 
 
  /** 
   * 上传单个文件，并返回其在服务器中的存储路径 
   * 
   * @param aFile 
   * @return 
   * @throws FileNotFoundException 
   * @throws IOException 
   */ 
  private static String uploadFile(MultipartFile aFile) throws IOException { 
    String filePath = initFilePath(aFile.getOriginalFilename()); 
    try { 
      write(aFile.getInputStream(), new FileOutputStream(filePath)); 
    } catch (FileNotFoundException e) { 
      logger.error("上传的文件: " + aFile.getName() + " 不存在！！"); 
      e.printStackTrace(); 
    } 
    return filePath; 
  } 
 
  /** 
   * 写入数据 
   * 
   * @param in 
   * @param out 
   * @throws IOException 
   */ 
  private static void write(InputStream in, OutputStream out) throws IOException { 
    try { 
      byte[] buffer = new byte[1024]; 
      int bytesRead = -1; 
      while ((bytesRead = in.read(buffer)) != -1) { 
        out.write(buffer, 0, bytesRead); 
      } 
      out.flush(); 
    } finally { 
      try { 
        in.close(); 
        out.close(); 
      } catch (IOException ex) { 
      } 
    } 
  } 
 
  /** 
   * 遍历服务器目录，列举出目录中的所有文件（含子目录） 
   * @return 
   */ 
  public static Map<String, String> getFileMap() { 
    logger.info(FileUploadingUtil.FILEDIR); 
    Map<String, String> map = new HashMap<String, String>(); 
    File[] files = new File(FileUploadingUtil.FILEDIR).listFiles(); 
    if (files != null) { 
      for (File file : files) { 
        if (file.isDirectory()) { 
          File[] files2 = file.listFiles(); 
          if (files2 != null) { 
            for (File file2 : files2) { 
              String name = file2.getName(); 
              logger.info(file2.getParentFile().getAbsolutePath()); 
              logger.info(file2.getAbsolutePath()); 
              map.put(file2.getParentFile().getName() + "/" + name, 
                  name.substring(name.lastIndexOf("_") + 1)); 
            } 
          } 
        } 
      } 
    } 
    return map; 
  } 
 
  /** 
   * 返回文件存储路径，为防止重名文件被覆盖，在文件名称中增加了随机数 
   * @param name 
   * @return 
   */ 
  private static String initFilePath(String name) { 
    String dir = getFileDir(name) + ""; 
    File file = new File(FILEDIR + dir); 
    if (!file.exists()) { 
      file.mkdir(); 
    } 
    Long num = new Date().getTime(); 
    Double d = Math.random() * num; 
    return (file.getPath() + "/" + num + d.longValue() + "_" + name).replaceAll(" ", "-"); 
  } 
 
  /** 
   * 
   * @param name 
   * @return 
   */ 
  private static int getFileDir(String name) { 
    return name.hashCode() & 0xf; 
  } 
} 

package com.emerson.cwms.web;  


import java.io.IOException; 
import java.util.Iterator; 
import java.util.Map; 
import java.util.Map.Entry; 
 
import javax.servlet.http.HttpServletRequest; 
import javax.servlet.http.HttpServletResponse; 
 
import org.springframework.stereotype.Controller; 
import org.springframework.ui.Model; 
import org.springframework.web.bind.annotation.RequestMapping; 
import org.springframework.web.bind.annotation.RequestMethod; 
import org.springframework.web.multipart.MultipartHttpServletRequest; 
 
import com.emerson.cwms.utils.FileUploadingUtil; 
 
/** 
 * 文件上传控制器 
 * 
 * @author Chris Mao(Zibing) 
 * 
 */ 
@Controller 
@RequestMapping(value = "/files") 
public class FileController { 
   
  @RequestMapping(value = "/", method = RequestMethod.GET) 
  public String list(HttpServletRequest request, HttpServletResponse response, Model model) { 
    iniFileDir(request); 
     
    System.out.println(request.getAttribute("files")); 
    model.addAttribute("files", FileUploadingUtil.getFileMap()); 
    return "files/list"; 
  } 
   
  @RequestMapping(value = "/upload", method = RequestMethod.POST) 
  public String doUpload(HttpServletRequest request) { 
    iniFileDir(request); 
     
    try { 
      MultipartHttpServletRequest mRequest = (MultipartHttpServletRequest) request; 
      Map<String, String> uploadedFiles = FileUploadingUtil.upload(mRequest.getFileMap()); 
 
      Iterator<Entry<String, String>> iter = uploadedFiles.entrySet().iterator(); 
      while (iter.hasNext()) { 
        Entry<String, String> each = iter.next(); 
        System.out.print("Uploaded File Name = " + each.getKey()); 
        System.out.println(", Saved Path in Server = " + each.getValue()); 
      } 
    } catch (Exception e) { 
      e.printStackTrace(); 
    } 
    return "redirect:/files/"; 
  } 
 
  private void iniFileDir(HttpServletRequest request) { 
    FileUploadingUtil.FILEDIR = request.getSession().getServletContext().getRealPath("/") + "files/"; 
    if (FileUploadingUtil.FILEDIR == null) { 
      FileUploadingUtil.FILEDIR = request.getSession().getServletContext().getRealPath("/") + "files/"; 
    } 
  } 
} 

<dependency> 
  <groupId>commons-fileupload</groupId> 
  <artifactId>commons-fileupload</artifactId> 
  <version>1.3.1</version> 
</dependency>