fileupload简单使用

form.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
    <form action="/day22/demo1" enctype="multipart/form-data" method="post">
        用户名:<input type="text" name="username"><br>
        文件:<input type="file" name="f"><br>
        <input type="submit"><br>
    </form>
</body>
</html>

Demo1Servlet

package com;

import java.io.IOException;
import java.io.InputStream;
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;

/**
 *文件上传
 */
public class Demo1Servlet extends HttpServlet {

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        /*String username = request.getParameter("username");
        String f=request.getParameter("f");
        System.out.println(username);
        System.out.println(f);*/

        //创建磁盘文件项工厂
        DiskFileItemFactory factory = new DiskFileItemFactory();

        //创建核心上传对象
        ServletFileUpload upload = new ServletFileUpload(factory);

        //解析请求
        try {
            List<FileItem> list = upload.parseRequest(request);
            //遍历list

            for (FileItem fi : list) {
                //判断是普通的上传组件还是文件上传组件
                if(fi.isFormField()){
                    //普通的上传组件
                    //获取name属性
                    String name = fi.getFieldName();

                    //获取值
                    String string = fi.getString("utf-8");

                    System.out.println(name+"::"+string);
                }else{
                    //文件上传组件
                    //获取name属性
                    String name = fi.getFieldName();

                    //获取文件的名称
                    String filename = fi.getName();

                    //获取文件内容
                    InputStream is = fi.getInputStream();

                    System.out.println("文件:"+name+"::"+filename+"::"+is);
                }

            }

        } catch (FileUploadException e) {
            e.printStackTrace();
        }
    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        doGet(request, response);
    }

}