Servlet文件上传问题

时间:2022-08-29 12:40:20

页面代码

<%@ page language="java" pageEncoding="UTF-8"%>
<!DOCTYPE HTML>
<html>
  <head>
    <title>文件上传</title>
  </head>
 
  <body>
    <!--<form action="${pageContext.request.contextPath}/systemupload/uploadgo.do"  enctype="multipart/form-data" method="post">
         上传用户:<input type="text" name="username"><br/>
         上传文件1:<input type="file" name="file1"><br/>
         上传文件2:<input type="file" name="file2"><br/>
        <input type="submit" value="提交">
    </form>
    --><form method="post" action="${pageContext.request.contextPath}/systemupload/uploadgo.do"  enctype="multipart/form-data">
      <table>
       <tr>
        <td>请选择文件1:</td>
        <td><input type="file" name="file1"/></td>
    </tr>
    <tr>
     <td>请选择文件2:</td>
        <td><input type="file" name="file2"/></td>
    </tr>
    <tr>
        <td abbr="2"><input type="submit" value="上传"/></td>
    </tr>
      </table>
     
     </form>
  </body>
</html>

 

 

 

 

 

 

 

 

 

 

 

 

 

 

java代码

 

package com.infosky.wep.action.system;

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 java.util.Map;
import java.util.UUID;

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.FileUploadBase;
import org.apache.commons.fileupload.ProgressListener;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

 


@Controller
@RequestMapping("/systemupload")
public class UploadHandleServlet extends HttpServlet {
 @RequestMapping("/getuploadpage.do")
 public String getpage(HttpServletRequest request, HttpServletResponse response, Map<String, Object> map) throws ServletException, IOException{
  map.put("id", "system/upload.jsp");
  return "control/public";
 }
 
// public void doGet(HttpServletRequest request, HttpServletResponse response){
//  try {
//   upload(request,response);
//  } catch (Exception e) {
//   // TODO Auto-generated catch block
//   e.printStackTrace();
//  }
//  
// }
// public void upload(HttpServletRequest request,HttpServletResponse response) throws IOException, ServletException{
//  //获得文件磁盘条目工厂
//  DiskFileItemFactory factory=new DiskFileItemFactory();
//  //获取文件上传的路径
//  String path=request.getSession().getServletContext().getRealPath("/WEB-INF/upload");
//  //设置暂时存放的存储路径,这个路径可和真正的存储路径不同
//  factory.setRepository(new File(path));
//  //设置缓存大小,上传文件时超过该设置大小时放入存储室
//  factory.setSizeThreshold(1024*1024);
//  //高水平的api上传处理
//  ServletFileUpload upload=new ServletFileUpload(factory);
//  try {
//   String name1= request.getParameter("file1");
//   //可以存放前台上穿的文件
//   List<FileItem> list=(List<FileItem>)upload.parseRequest(request);
//   //遍历文件类表
//   for (FileItem item : list) {
//    //获取表的的属性名
//    String name=item.getFieldName();
//    //判断表单信息是否是普通的文本信息
//    if(item.isFormField()){
//     //文本信息处理方法
//     String value=item.toString();
//     request.setAttribute(name, value);
//    }else{
//     //非字符串信息处理方法
//     //获取路径名
//     String value=item.getName();
//     //索引到最后一个\
//     int start=value.lastIndexOf("\\");
//     //截取文件的字符串名称
//     String fileName=value.substring(start+1);
//     request.setAttribute(name, value);
//     //真正写入磁盘
//     item.write(new File(path,fileName));
//     OutputStream out =new FileOutputStream(new File(path,fileName));
//     InputStream in=item.getInputStream();
//     int length=0;
//     byte[] buf=new byte[1024];
//     System.out.println("获取上传文件的总容量:"+item.getSize());
//     while ((length=in.read(buf))!=-1) {
//      out.write(buf,0,length);
//      
//     }
//     in.close();
//     out.close();
//    }
//   }
//  } catch (Exception e) {
//   // TODO: handle exception
//  }
//  request.getRequestDispatcher("/index.jsp").forward(request, response);
// }
 @RequestMapping("/uploadgo.do")
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
//    //得到上传文件的保存目录,将上传的文件存放于WEB-INF目录下,不允许外界直接访问,保证上传文件的安全
//                String savePath = this.getServletContext().getRealPath("/");
//                //上传时生成的临时文件保存目录
//                String tempPath = this.getServletContext().getRealPath("/");
    String savePath = request.getSession().getServletContext().getRealPath("/WEB-INF/upload");
    String tempPath = request.getSession().getServletContext().getRealPath("/WEB-INF/temp");
                File tmpFile = new File(tempPath);
                if (!tmpFile.exists()) {
                    //创建临时目录
                    tmpFile.mkdir();
                }
               
                //消息提示
                String message = "";
                try{
                    //使用Apache文件上传组件处理文件上传步骤:
                    //1、创建一个DiskFileItemFactory工厂
                    DiskFileItemFactory factory = new DiskFileItemFactory();
                    //设置工厂的缓冲区的大小,当上传的文件大小超过缓冲区的大小时,就会生成一个临时文件存放到指定的临时目录当中。
                    factory.setSizeThreshold(1024*100);//设置缓冲区的大小为100KB,如果不指定,那么缓冲区的大小默认是10KB
                    //设置上传时生成的临时文件的保存目录
                    factory.setRepository(tmpFile);
                    //2、创建一个文件上传解析器
                    ServletFileUpload upload = new ServletFileUpload(factory);
                    //监听文件上传进度
                    upload.setProgressListener(new ProgressListener(){
                        public void update(long pBytesRead, long pContentLength, int arg2) {
                            System.out.println("文件大小为:" + pContentLength + ",当前已处理:" + pBytesRead);
                            /**
                             * 文件大小为:14608,当前已处理:4096
                                  文件大小为:14608,当前已处理:7367
                                  文件大小为:14608,当前已处理:11419
                                  文件大小为:14608,当前已处理:14608
                             */
                        }
                    });
                     //解决上传文件名的中文乱码
                    upload.setHeaderEncoding("UTF-8");
                    //3、判断提交上来的数据是否是上传表单的数据
                    if(!ServletFileUpload.isMultipartContent(request)){
                        //按照传统方式获取数据
                        return;
                    }
                   
                    //设置上传单个文件的大小的最大值,目前是设置为1024*1024字节,也就是1MB
                    upload.setFileSizeMax(1024*1024);
                    //设置上传文件总量的最大值,最大值=同时上传的多个文件的大小的最大值的和,目前设置为10MB
                    upload.setSizeMax(1024*1024*10);
                    //4、使用ServletFileUpload解析器解析上传数据,解析结果返回的是一个List<FileItem>集合,每一个FileItem对应一个Form表单的输入项
                    List<FileItem> list = upload.parseRequest(request);
                    for(FileItem item : list){
                        //如果fileitem中封装的是普通输入项的数据
                        if(item.isFormField()){
                            String name = item.getFieldName();
                            //解决普通输入项的数据的中文乱码问题
                            String value = item.getString("UTF-8");
                            //value = new String(value.getBytes("iso8859-1"),"UTF-8");
                            System.out.println(name + "=" + value);
                        }else{//如果fileitem中封装的是上传文件
                            //得到上传的文件名称,
                            String filename = item.getName();
                            System.out.println(filename);
                            if(filename==null || filename.trim().equals("")){
                                continue;
                            }
                            //注意:不同的浏览器提交的文件名是不一样的,有些浏览器提交上来的文件名是带有路径的,如:  c:\a\b\1.txt,而有些只是单纯的文件名,如:1.txt
                            //处理获取到的上传文件的文件名的路径部分,只保留文件名部分
                            filename = filename.substring(filename.lastIndexOf("\\")+1);
                            //得到上传文件的扩展名
                            String fileExtName = filename.substring(filename.lastIndexOf(".")+1);
                            //如果需要限制上传的文件类型,那么可以通过文件的扩展名来判断上传的文件类型是否合法
                            System.out.println("上传的文件的扩展名是:"+fileExtName);
                            //获取item中的上传文件的输入流
                            InputStream in = item.getInputStream();
                            //得到文件保存的名称
                            String saveFilename = makeFileName(filename);
                            //得到文件的保存目录
                            String realSavePath = makePath(saveFilename, savePath);
                            //创建一个文件输出流
                            FileOutputStream out = new FileOutputStream(realSavePath + "\\" + saveFilename);
                            //创建一个缓冲区
                            byte buffer[] = new byte[1024];
                            //判断输入流中的数据是否已经读完的标识
                            int len = 0;
                            //循环将输入流读入到缓冲区当中,(len=in.read(buffer))>0就表示in里面还有数据
                            while((len=in.read(buffer))>0){
                                //使用FileOutputStream输出流将缓冲区的数据写入到指定的目录(savePath + "\\" + filename)当中
                                out.write(buffer, 0, len);
                            }
                            //关闭输入流
                            in.close();
                            //关闭输出流
                            out.close();
                            //删除处理文件上传时生成的临时文件
                            //item.delete();
                            message = "文件上传成功!";
                        }
                    }
                }catch (FileUploadBase.FileSizeLimitExceededException e) {
                    e.printStackTrace();
                    request.setAttribute("message", "单个文件超出最大值!!!");
                    request.getRequestDispatcher("/message.jsp").forward(request, response);
                    return;
                }catch (FileUploadBase.SizeLimitExceededException e) {
                    e.printStackTrace();
                    request.setAttribute("message", "上传文件的总的大小超出限制的最大值!!!");
                    request.getRequestDispatcher("/message.jsp").forward(request, response);
                    return;
                }catch (Exception e) {
                    message= "文件上传失败!";
                    e.printStackTrace();
                }
                request.setAttribute("message",message);
                request.getRequestDispatcher("/index.jsp").forward(request, response);
    }
   
 
    private String makeFileName(String filename){  //2.jpg
        //为防止文件覆盖的现象发生,要为上传文件产生一个唯一的文件名
        return UUID.randomUUID().toString() + "_" + filename;
    }
   
    /**
     * 为防止一个目录下面出现太多文件,要使用hash算法打散存储
    * @Method: makePath
    * @param filename 文件名,要根据文件名生成存储目录
    * @param savePath 文件存储路径
    * @return 新的存储目录
    */
    private String makePath(String filename,String savePath){
        //得到文件名的hashCode的值,得到的就是filename这个字符串对象在内存中的地址
        int hashcode = filename.hashCode();
        int dir1 = hashcode&0xf;  //0--15
        int dir2 = (hashcode&0xf0)>>4;  //0-15
        //构造新的保存目录
        String dir = savePath + "\\" + dir1 + "\\" + dir2;  //upload\2\3  upload\3\5
        //File既可以代表文件也可以代表目录
        File file = new File(dir);
        //如果目录不存在
        if(!file.exists()){
            //创建目录
            file.mkdirs();
        }
        return dir;
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        doGet(request, response);
    }
}