文件上传

<pre name="code" class="html">package cn.itcast.web.servlet;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;
import java.util.UUID;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileUploadBase;
import org.apache.commons.fileupload.ProgressListener;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

public class UploadServlet1 extends HttpServlet {

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		//request.getParameter("username");  //****错误
		request.setCharacterEncoding("UTF-8");  //表单为文件上传，设置request编码无效
		
		//得到上传文件的保存目录
		String savePath = this.getServletContext().getRealPath("/WEB-INF/upload");
		
		try{
			DiskFileItemFactory factory = new DiskFileItemFactory();
			factory.setRepository(new File(this.getServletContext().getRealPath("/WEB-INF/temp")));
			
			ServletFileUpload upload = new ServletFileUpload(factory);
			/*upload.setProgressListener(new ProgressListener(){
				public void update(long pBytesRead, long pContentLength, int arg2) {
					System.out.println("文件大小为：" + pContentLength + ",当前已处理：" + pBytesRead);
				}
			});*/
			
			upload.setHeaderEncoding("UTF-8");  //解决上传文件名的中文乱码
			
			if(!upload.isMultipartContent(request)){
				//按照传统方式获取数据
				return;
			}
			
			
			/*upload.setFileSizeMax(1024);
			upload.setSizeMax(1024*10);*/
			List<FileItem> list = upload.parseRequest(request);
			for(FileItem item : list){
				
				if(item.isFormField()){
					//fileitem中封装的是普通输入项的数据
					String name = item.getFieldName();
					String value = item.getString("UTF-8");
					//value = new String(value.getBytes("iso8859-1"),"UTF-8");
					System.out.println(name + "=" + value);
				}else{
					//fileitem中封装的是上传文件
					String filename = item.getName();  //不同的浏览器提交的文件是不一样  c:\a\b\1.txt   1.txt
					System.out.println(filename);
					if(filename==null || filename.trim().equals("")){
						continue;
					}
					filename = filename.substring(filename.lastIndexOf("\\")+1);
					
					InputStream in = item.getInputStream();
					String saveFilename = makeFileName(filename);  //得到文件保存的名称
					
					String realSavePath = makePath(saveFilename, savePath);  //得到文件的保存目录
					FileOutputStream out = new FileOutputStream(realSavePath + "\\" + saveFilename);
					byte buffer[] = new byte[1024];
					int len = 0;
					while((len=in.read(buffer))>0){
						out.write(buffer, 0, len);
					}
					
					in.close();
					out.close();
					item.delete();  //删除临时文件
					
				}
				
			}
		
		}catch (FileUploadBase.FileSizeLimitExceededException e) {
			e.printStackTrace();
			request.setAttribute("message", "文件超出最大值！！！");
			request.getRequestDispatcher("/message.jsp").forward(request, response);
			return;
		}
		catch (Exception e) {
			e.printStackTrace();
		}
	}
	
	public String makeFileName(String filename){  //2.jpg
		return UUID.randomUUID().toString() + "_" + filename;
	}
	
	public String makePath(String filename,String savePath){
		
		int hashcode = filename.hashCode();
		int dir1 = hashcode&0xf;  //0--15
		int dir2 = (hashcode&0xf0)>>4;  //0-15
		
		String dir = savePath + "\\" + dir1 + "\\" + dir2;  //upload\2\3  upload\3\5
		File file = new File(dir);
		if(!file.exists()){
			file.mkdirs();
		}
		return dir;
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		doGet(request, response);
	}

}