FileUpload框架实现文件上传(多个文件)和下载

一、文件上传：

　　对于大文件执行下面的代码之间卡死

package com.example.web.service.servlet;



import java.io.File;

import java.io.IOException;

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.FileItemFactory;

import org.apache.commons.fileupload.disk.DiskFileItemFactory;

import org.apache.commons.fileupload.servlet.ServletFileUpload;

public class FileUpload extends HttpServlet {

    private static final long serialVersionUID = 1L;

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

        this.doPost(request, response);

    }

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

        try {

            FileItemFactory factory = new DiskFileItemFactory();

            ServletFileUpload upload = new ServletFileUpload(factory);

            List<FileItem> items = upload.parseRequest(request);

            String dir = request.getSession().getServletContext().getRealPath("/files");

            File dirFile= new File(dir);

            if(!dirFile.exists())

                dirFile.mkdirs();

            for (FileItem fileItem : items) {

                //文本类型

                if(fileItem.isFormField()){

                    String name =fileItem.getFieldName();

                    String value=fileItem.getString();

                    System.out.println(" name: "+name+" value: "+value);

                }else {

                    System.out.println(" 上传文件目录: "+dir);

                    File saveFile = new File(dir,fileItem.getName());

                    fileItem.write(saveFile);

                }

            }                                

        } catch (Exception e) {

            e.printStackTrace();

        }

    }

}

　　jsp界面，上传文件时form表单必须有 enctype="multipart/form-data"

<form action="<%=request.getContextPath() %>/FileUpload" method="post" enctype="multipart/form-data">

        <input type="text" name="name" > <br>

        <input type="file" name="file1"> <br>

        <input type="file" name="file2"> <br>

        <input type="submit" value=" submit ">

</form>