实现文件上传的方式
1、进入http://commons.apache.org/proper/commons-fileupload/using.html
2、点击用户指南
3、对着用户指南一步步复制粘贴，并把代码撸成自己想要的样子
补充：记得要将commons-io-2.4.jar和commons-fileupload-1.2.2.jar这两个包放到编译器里面
现成的代码
JSP 前端页面
<%-- Created by IntelliJ IDEA. User: Administrator Date: 2019/10/8 Time: 16:14 To change this template use File | Settings | File Templates.--%><%@ page contentType="text/html;charset=UTF-8" language="java" %><html><head> <title>作业三第1遍</title></head><body>文件上传注意事项：<br><ol> <li>提交方式必须是post</li> <li>enctype="multipart/form-data"是以字节数据的形式提交表单，否则默认是kv形式，只会提交文件名</li> <li>如果以默认的application/x-mons.fileupload.servlet.ServletFileUpload;import javax.servlet.ServletException;import javax.servlet.ServletInputStream;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.File;import java.io.IOException;import java.io.UnsupportedEncodingException;import java.util.Enumeration;import java.util.Iterator;import java.util.List;@WebServlet(name = "UploadServlet", urlPatterns = "/UploadServlet")public class UploadServlet extends HttpServlet { protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //处理中文乱码--已经测试这个要不要无所谓 request.setCharacterEncoding("UTF-8"); //判断是不是传入的一个二进制的流 boolean isMultipart = ServletFileUpload.isMultipartContent(request); //创建一个简单工厂实例 FileItemFactory factory = new DiskFileItemFactory(); //创建一个新的文件上传处理程序 ServletFileUpload upload = new ServletFileUpload(factory); //解析request try { List<FileItem> fileItems = upload.parseRequest(request); //处理上传的项目 Iterator iter=fileItems.iterator(); while(iter.hasNext()){ FileItem item = (FileItem) iter.next(); if (item.isFormField()){ //普通域 processFormField(item); }else{ //文件域 此处注意processUploadFile()方法的参数里面传入request的目的是让下面写文件的时候获取根目录用的 processUploadFile(item,request); } } } catch (FileUploadException e) { e.printStackTrace(); } ServletInputStream inputStream = request.getInputStream(); byte[] bs=new byte[1024]; int total=-1; while ((total=inputStream.read(bs))!=-1){ System.out.print(new String(bs,0,total)); } } /** * 文件域 * @param item * @param request */ private void processUploadFile(FileItem item, HttpServletRequest request) { //获取文件相关信息 String fileName=""; if (!item.isFormField()) { String fieldName = item.getFieldName(); fileName = item.getName(); String contentType = item.getContentType(); boolean isInMemory = item.isInMemory(); long sizeInBytes = item.getSize(); System.out.println("文件名： "+fileName+" 文件属性："+fieldName+" 文件大小："+sizeInBytes+" 文件类型："+contentType); } //以下是转存操作，找到储存文件的根路径 String fileRootPath=request.getServletContext().getRealPath("/WEB-INF/upload"); File dir = new File(fileRootPath); if (!dir.exists()){ dir.mkdirs(); } //写文件 File file = new File(fileRootPath+"/"+fileName); try { item.write(file); } catch (Exception e) { e.printStackTrace(); } } /** * 普通域 * @param item */ private void processFormField(FileItem item) { String key = item.getFieldName(); String value = null; try { //处理中文乱码 value = item.getString("UTF-8"); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } System.out.println(key+"----"+value); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { } @Override protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { super.service(req, resp); System.out.println("刷新...."); } @Override public void init() throws ServletException { super.init(); System.out.println("初始化...."); }}
运行结果
//说明：路径出现的位置就是网页发布的路径
//说明：路径出现的位置就是网页发布的路径
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。
