|--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
1 <%-- 2 Created by IntelliJ IDEA. 3 User: Administrator 4 Date: 2019/10/8 5 Time: 16:14 6 To change this template use File | Settings | File Templates. 7 --%> 8 <%@ page contentType="text/html;charset=UTF-8" language="java" %> 9 <html> 10 <head> 11 <title>作业三第1遍</title> 12 </head> 13 <body> 14 文件上传注意事项：<br> 15 <ol> 16 <li>提交方式必须是post</li> 17 <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> 18 <li>如果以默认的application/x-www-form-urlencode的方式提交，上传的就不是文件本身</li> 19 </ol> 20 <%--application/x-www-form-urlencoded 以键值对的方式上传 --%> 21 <%-- multipart/form-data 以二进制的方式上传 --%> 22 <form action="/work/UploadServlet" method="post" enctype="multipart/form-data"> 23 <input type="text" name="data1" value="data1Value"> 24 <hr> 25 <input type="text" name="data2" value="data2Value"> 26 <hr> 27 <input type="file" name="dataFile"> 28 <hr> 29 <input type="submit" value="上传该表单"> 30 <hr> 31 </form> 32 33 34 </body> 35 </html>
1 package com.bd25;
2
3 import org.apache.commons.fileupload.FileItem;
4 import org.apache.commons.fileupload.FileItemFactory;
5 import org.apache.commons.fileupload.FileUploadException;
6 import org.apache.commons.fileupload.disk.DiskFileItemFactory;
7 import org.apache.commons.fileupload.servlet.ServletFileUpload;
8
9 import javax.servlet.ServletException;
10 import javax.servlet.ServletInputStream;
11 import javax.servlet.annotation.WebServlet;
12 import javax.servlet.http.HttpServlet;
13 import javax.servlet.http.HttpServletRequest;
14 import javax.servlet.http.HttpServletResponse;
15 import java.io.File;
16 import java.io.IOException;
17 import java.io.UnsupportedEncodingException;
18 import java.util.Enumeration;
19 import java.util.Iterator;
20 import java.util.List;
21
22 @WebServlet(name = "UploadServlet", urlPatterns = "/UploadServlet")
23 public class UploadServlet extends HttpServlet {
24 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
25 //处理中文乱码--已经测试这个要不要无所谓
26 request.setCharacterEncoding("UTF-8");
27
28 //判断是不是传入的一个二进制的流
29 boolean isMultipart = ServletFileUpload.isMultipartContent(request);
30 //创建一个简单工厂实例
31 FileItemFactory factory = new DiskFileItemFactory();
32 //创建一个新的文件上传处理程序
33 ServletFileUpload upload = new ServletFileUpload(factory);
34 //解析request
35 try {
36 List<FileItem> fileItems = upload.parseRequest(request);
37 //处理上传的项目
38 Iterator iter=fileItems.iterator();
39 while(iter.hasNext()){
40 FileItem item = (FileItem) iter.next();
41 if (item.isFormField()){
42 //普通域
43 processFormField(item);
44 }else{
45 //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
46 processUploadFile(item,request);
47 }
48
49 }
50
51 } catch (FileUploadException e) {
52 e.printStackTrace();
53 }
54
55
56 ServletInputStream inputStream = request.getInputStream();
57 byte[] bs=new byte[1024];
58 int total=-1;
59 while ((total=inputStream.read(bs))!=-1){
60 System.out.print(new String(bs,0,total));
61 }
62 }
63
64 /**
65 * 文件域
66 * @param item
67 * @param request
68 */
69 private void processUploadFile(FileItem item, HttpServletRequest request) {
70 //获取文件相关信息
71 String fileName="";
72 if (!item.isFormField()) {
73 String fieldName = item.getFieldName();
74 fileName = item.getName();
75 String contentType = item.getContentType();
76 boolean isInMemory = item.isInMemory();
77 long sizeInBytes = item.getSize();
78 System.out.println("文件名： "+fileName+" 文件属性："+fieldName+" 文件大小："+sizeInBytes+" 文件类型："+contentType);
79 }
80 //以下是转存操作，找到储存文件的根路径
81 String fileRootPath=request.getServletContext().getRealPath("/WEB-INF/upload");
82 File dir = new File(fileRootPath);
83 if (!dir.exists()){
84 dir.mkdirs();
85 }
86 //写文件
87 File file = new File(fileRootPath+"/"+fileName);
88 try {
89 item.write(file);
90 } catch (Exception e) {
91 e.printStackTrace();
92 }
93 }
94
95 /**
96 * 普通域
97 * @param item
98 */
99 private void processFormField(FileItem item) {
100 String key = item.getFieldName();
101 String value = null;
102 try {
103 //处理中文乱码
104 value = item.getString("UTF-8");
105 } catch (UnsupportedEncodingException e) {
106 e.printStackTrace();
107 }
108 System.out.println(key+"----"+value);
109 }
110
111 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
112
113 }
114
115 @Override
116 protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
117 super.service(req, resp);
118 System.out.println("刷新....");
119 }
120
121 @Override
122 public void init() throws ServletException {
123 super.init();
124 System.out.println("初始化....");
125 }
126 }
|--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
