Servlet+Jsp实现图片或文件的上传功能具体思路及代码（servletjsp深入详解）干货分享

package load;

import java.io.File;

import java.io.IOException;

import java.io.PrintWriter;

import java.util.List;

import javax.servlet.ServletContext;

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;

public class UpLoad extends HttpServlet {

@SuppressWarnings(“unchecked”)

@Override

protected void service(HttpServletRequest req, HttpServletResponse resp)

throws ServletException, IOException {

req.setCharacterEncoding(“utf-8”);

resp.setContentType(“text/html;charset=utf-8”);

//为解析类提供配置信息

DiskFileItemFactory factory=new DiskFileItemFactory();

//创建解析类的实例

ServletFileUpload sfu=new ServletFileUpload(factory);

//开始解析

sfu.setFileSizeMax(1024*400);

//每个表单域中数据会封装到一个对应的FileItem对象上

try {

List items=sfu.parseRequest(req);

//区分表单域

for (int i=0; i < items.size(); i++) {

FileItem item=items.get(i);

//isFormField为true，表示这不是文件上传表单域

if(!item.isFormField()){

ServletContext sctx=getServletContext();

//获得存放文件的物理路径

//upload下的某个文件夹 得到当前在线的用户 找到对应的文件夹

String path=sctx.getRealPath(“/upload”);

System.out.println(path);

//获得文件名

String fileName=item.getName();

System.out.println(fileName);

//该方法在某些平台(操作系统),会返回路径+文件名

fileName=fileName.substring(fileName.lastIndexOf(“/”)+1);

File file=new File(path+”\”+fileName);

if(!file.exists()){

item.write(file);

//将上传图片的名字记录到数据库中

resp.sendRedirect(“/upload/ok.html”);

}

}

}

} catch (Exception e) {

e.printStackTrace();

}

}

}