java实现文件的上传功能

更新时间:2023-04-04 19:46:46 阅读：评论：0

本文实例为大家分享了java实现文件的上传功能的具体代码，供大家参考，具体内容如下

直接上代码了

一、上传界面

<%@ page language="java" contenttype="text/html; chart=utf-8"  pageencoding="utf-8"%><!doctype html public "-//w3c//dtd html 4.01 transitional//en" "http:四个成语//www.w3.org/tr/html4/loo.dtd"><html><head><meta http-equiv="content-type" content="text/html; chart=utf-8"><title>inrt title here</title></head><body> <!-- 文件上传对表单的要求 1、表单中的请求和提交的方式必须是post 2、 表单中应该指定提交的请求为multipart 请求 ,通过在form表单中添加enctype属性 为multipart/form-data 3、表单中要有file元素  --> <!-- ${pagecontext.request.contextpath}/registerrvlet --> <form action="${pagecontext.request.contextpath }/registerrvlet" method="post" enctype="multipart/form-data"> 姓名:<input type="text" name="name" /><br> <hr> 年龄:<input type="t山市ext" name="age" /><br>  <hr> 照片 :<input type="file" name="photo"/> <br>  <hr> <input type="submit" value="注册">  <hr> </form></body></html>

二、rvlet处理

package com.ui.rvlet;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.rvlet.rvletexception;import javax.rvlet.annotation.web正部级有多少人rvlet;import javax.rvlet.http.httprvlet;import javax.rvlet.http.httprvletrequest;import javax.rvlet.http.httprvletrespon;import org.apache.commons.fileupload.fileitem;import org.apache.commons.fileupload.disk.diskfileitemfactory;import org.apache.commons.fileupload.rvlet.rvletfileupload;import org.apache.tomcat.jni.os;import com.mysql.jdbc.field;/*** rvlet implementation class registerrvlet*/@webrvlet("/registerrvlet")p麻木的近义词ublic class registerrvlet extends httprvlet { private static final long rialversionuid = 1l; /**  * @e httprvlet#dopost(httprvletrequest request, httprvletrespon respon)  */ protected void dopost(httprvletrequest request, httprvletrespon respon) throws rvletexception, ioexception {  // todo auto-generated method stub  if(!rvletfileupload.ismultipartcontent(request))  {   throw new runtimeexception("当前不支持文件上传");  }  try {   diskfileitemfactory factory=new diskfileitemfactory();      //设置使用临时文件的边界值，大鱼该值得文件上传会先保存在临时文件中，否则上传文件会直接写入到内存当中去   //单位 字节 在这里设置的为1m   factory.tsizethreshold(1024*1024*1);   //设置临时文件   string temppath=this.getrvletcontext().getrealpath("/temp");   file file2=new file(temppath);   factory.trepository(file2);   //创建文件上传核心组件   rvletfileupload fileupload=new rvletfileupload(factory);   //设置单个文件的大小不超过多少   fileupload.tfilesizemax(1024*1024*2);   //上传多个文件的要求总的大小不超过多少   fileupload.tsizemax(1024*1024*5);   fileupload.theaderencoding("utf-8");   //设置每一个item的字符编码为utf-8      list<fileitem> items=fileupload.parrequest(request);   for (fileitem fileitem : items) {     if(fileitem.isformfield())     {      string filename=fileitem.getfieldname();      string filevalue=fileitem.getstring("utf-8");      system.out.println(filename+"----"+filevalue);          }     el //如果是文件上传表单项     {      string filename=fileitem.getname();      inputstream inputstream=fileitem.getinputstream();      //获取表单项的输入流      string path=this.getrvletcontext().getrealpath("/filecontents");      file file=new file(path,filename);      outputstream outputstream=new fileoutputstream(file);      int len=-1;      byte[] bs=new byte[1024];      while((len=inputstream.read(bs))!=-1)        {              outputstream.write(bs,0,len);                      }      outputstream.clo();      inputstream.clo();      //删除临时文件      fileitem.delete();     }   }  }  catch (exception e) {   // todo: handle exception   system.out.println(e);  } }}