使用commons-fileupload实现上传

看了个视频

有apache组织提供的commons－fileupload ，实现上传

 jsp页面，web.xml省略

servlet

 

package com.xie.fileupload;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.List;
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.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

public class FileUpload extends HttpServlet ...{

    @SuppressWarnings("unchecked")
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException ...{
        DiskFileItemFactory factory = new DiskFileItemFactory();
        String path = request.getRealPath("/upload");
        factory.setRepository(new File(path));
        factory.setSizeThreshold(1024 * 1024);

        ServletFileUpload upload = new ServletFileUpload(factory);

        try ...{
            List<FileItem> list = upload.parseRequest(request);

            for (FileItem fileItem : list) ...{
                // 如果是表单信息
                if (fileItem.isFormField()) ...{
                    String name = fileItem.getFieldName();// 获得表单中的名字
                    String value = fileItem.getString("gbk");
                    request.setAttribute(name, value);
                } else ...{
                    String name = fileItem.getFieldName();
                    String value = fileItem.getName();// 获得从浏览器中取得的文件名字

                    int start = value.lastIndexOf("/");
                    String fileName = value.substring(start + 1); // 由于不同的浏览器可能取得的文件的名字不同，有的浏览器将整个路径取道，有的浏览器只取到文件名
                    request.setAttribute(name, fileName);// 形如c:document....
.txt和1.txt这两种形式，因此需要做次操作

                    // 使用io进行文件的上传
                    /**//*
                     * OutputStream os = new FileOutputStream(new
                     * File(path,fileName));
                     * 
                     * InputStream in = fileItem.getInputStream();
                     * 
                     * byte[] buffer = new byte[400];
                     * 
                     * int length = 0 ;
                     * 
                     * while((length - in.read(buffer))>0) { os.write(buffer, 0,
                     * length); }
                     * 
                     * os.close(); in.close();
                     */

                    // 使用fileupload提供的上传
                    try ...{
                        fileItem.write(new File(path, fileName));
                    } catch (Exception e) ...{
                        e.printStackTrace();
                    }
                }
            }
        } catch (FileUploadException e) ...{
            e.printStackTrace();
        }

        request.getRequestDispatcher("/fileUpload/success.jsp").forward(
                request, response);
    }

}