文件上传(1课时）

servlet3.1文件上传
参考：https://www.cnblogs.com/xdp-gacl/p/4224960.html

页面

    
    
${msg}
        

            name:

            email:

            上传文件：  
 
            
 
        

后台

        package com.neuedu.controller;

import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.UUID;

import javax.servlet.ServletException;
import javax.servlet.annotation.MultipartConfig;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.Part;

/**
 * Servlet implementation class UploadServlet
 */
@WebServlet("/UploadServlet")
@MultipartConfig
public class UploadServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public UploadServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("text/html;charset=utf-8");
        //设置存储路径
        //生产环境
        //String savePath = request.getServletContext().getRealPath("/upload");
        //开发环境
        String savePath = "D:/apache-tomcat-8.0.36/wtpwebapps/upload";
        String name=request.getParameter("name");
        Part part = request.getPart("f1");
        //自定义编写解析字符串的方法getFileName，获取文件名
        String oriFileName = part.getSubmittedFileName();//调用获取文件名的方法
        if(oriFileName.endsWith("JPG") || oriFileName.endsWith("PNG") || oriFileName.endsWith("jpg")|| oriFileName.endsWith("png")) {
            //获取原文件名后缀
            String suffix = oriFileName.substring(oriFileName.lastIndexOf("."));
            //避免上传后文件名称重复，使用uuid文件名
            String fileName=UUID.randomUUID().toString().replaceAll("-", "");
            fileName = fileName + suffix;
            // 把文件写到指定路径
            part.write(savePath + File.separator +fileName);
            PrintWriter out = response.getWriter();
            request.setAttribute("msg","上传成功"); 
            request.getRequestDispatcher("upload.jsp").forward(request, response);
        }else {
            request.setAttribute("msg","请上传图片类型的文件！");  
            request.getRequestDispatcher("upload.jsp").forward(request, response);
        }
    }
    
}

解决重启服务图片丢失的问题

总体是通过配置tomcat虚拟目录来实现
0)在D:\apache-tomcat-8.0.36\wtpwebapps下新建upload目录
1)开发环境，文件上传时，传到D:\apache-tomcat-8.0.36\wtpwebapps\upload目录下。
2)eclipse的servers下找到server.xlml

image.png

增加如下配置：

3)测试

http://localhost:8081/java1/upload/430107639a9f476fa0f6a2ee3b48193e.png