一  form表单上传文件

前端

form表单上传文件    
     
              用户名
      
      
        头像
      
      
        
          
     

实体类

package com.qy.entity;public class User {    private String username;    private String myPic;    public String getUsername() {        return username;    }    public void setUsername(String username) {        this.username = username;    }    public String getMyPic() {        return myPic;    }    public void setMyPic(String myPic) {        this.myPic = myPic;    }        }

 

后端servlet

package com.qy.servlet;import java.io.IOException;import java.util.Arrays;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;import com.qy.entity.User;@WebServlet("/saveUser.do")@MultipartConfigpublic class UserSaveServlet extends HttpServlet{        @Override    protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        String username = request.getParameter("username");        Part part = request.getPart("myPic");        System.out.println(part);        //验证文件大小，后缀是否满足要求，获取原始文件名        long size = part.getSize();        //1m  1024*1024        if(size > 1024*1024){            System.out.println("文件大于1M！");            return ;        }        //        String file = part.getHeader("Content-Disposition");//form-data; name="myPic"; filename="1024.jpg"        //获取后缀  截取  .          String suffix = file.substring(file.lastIndexOf(".")+1, file.length()-1);        //比对后缀格式是否正确        String[] suffixs = {"jpg","png","gif"};content.lastIndexOf("=\"")+2,content.lastIndexOf("\"")        boolean flag = Arrays.asList(suffixs).contains(suffix);        if(!flag){            System.out.println("文件格式不正确！");            return ;        }        //获取保存路径        String path = request.getServletContext().getRealPath("/images/");                //保存文件到磁盘        String filename = System.currentTimeMillis()+"."+suffix;        part.write(path+filename);                        //保存用户数据到数据库        User user = new User();        user.setUsername(username);        user.setMyPic("images/"+filename);                //调用dao层方法保存对象                //控制页面跳转    }}

ajax上传文件

前端

ajax上传文件  
    
     
        
               
          
     

实体类与上面相同

后端servlet

package com.qy.servlet;import java.io.IOException;import java.util.Arrays;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;import com.qy.entity.User;@WebServlet("/saveUser2.do")@MultipartConfigpublic class UserSaveServlet2 extends HttpServlet{        @Override    protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        response.setContentType("text/html;charset=utf-8");                String username = request.getParameter("username");        Part part = request.getPart("myPic");        //验证文件大小，后缀是否满足要求，获取原始文件名        long size = part.getSize();        //1m  1024*1024        if(size > 1024*1024){            System.out.println("文件大于1M！");            response.getWriter().append("文件大于1M！");            return ;        }        //        String file = part.getHeader("Content-Disposition");//form-data; name="myPic"; filename="1024.jpg"        //获取后缀  截取  .          String suffix = file.substring(file.lastIndexOf(".")+1, file.length()-1);        //比对后缀格式是否正确        String[] suffixs = {"jpg","png","gif"};        boolean flag = Arrays.asList(suffixs).contains(suffix);        if(!flag){            System.out.println("文件格式不正确！");            response.getWriter().append("文件格式不正确!");            return ;        }        //获取保存路径        String path = request.getServletContext().getRealPath("/images/");                //保存文件到磁盘        String filename = System.currentTimeMillis()+"."+suffix;        part.write(path+filename);                        //保存用户数据到数据库        User user = new User();        user.setUsername(username);        user.setMyPic("images/"+filename);                //调用dao层方法保存对象                //返回保存成功        response.getWriter().append("上传成功！");    }}