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发布时间:2016-01-01 作者:网络 阅读:185次

本文实例讲述了JSP实现快速上传文件的方法。分享给大家供大家参考。具体如下:

这里演示JSP不使用第三方库,实现快速上传文件的功能

1. FileUpload.java:

package FileUpload;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import javax.servlet.ServletInputStream;
/**
 * 
 */
/**
 * @author Qch
 * 
 */
public class FileUpload
{
  ServletInputStream in=null;
  String fpath="C://";
  public FileUpload()
  {
    fpath="C://";
    in=null;
  }
  public void setInputStream(ServletInputStream in)
  {
    this.in=in;
  }
  public void setFpath(String p)
  {
    this.fpath=p;
  }
  public String getFpath()
  {
    return fpath;
  }
  public String getParameter()
  { 
    String r=null;
    try
    {
      r=getParameter(in);
    }
    catch (Exception e)
    {
      e.printStackTrace();
    }
    return r;
  }
  public long getFileUpload()
  {
    long r=-1;
    try
    {
      r=getFileUpload(in,fpath);
    }
    catch (Exception e)
    {
      e.printStackTrace();
    }
    return r;
  }
  public String getParameter(ServletInputStream in)// 只能按顺序提取
      throws Exception
  {
    int l = 0;
    byte[] b = new byte[1024];
    l = in.readLine(b, 0, b.length);// 依次是读取属性的开始符、名称、属性值的类型、属性的值
    String si = new String(b);
    if (si.startsWith("----------------------------"))
    {// 表示是从开始符开始读,否则应为刚读取文件后的一个属性,此时应少读一次
      l = in.readLine(b, 0, b.length);
    }
    l = in.readLine(b, 0, b.length);
    l = in.readLine(b, 0, b.length);
    String value = new String(b, 0, l);
    return value;
  }
  public long getFileUpload(ServletInputStream in, String fpath)// 需要提供输入流和存储路径
      throws Exception
  {
    // out.println("文件信息:
"); long begin = System.currentTimeMillis();// 传送时间计时开始 int l = 0; byte[] b = new byte[1024]; l = in.readLine(b, 0, b.length); String sign = new String(b, 0, l);// eg.-----------------------------7d9dd29630a34 l = in.readLine(b, 0, b.length); String info = new String(b, 0, l);// eg.Content-Disposition:form-data; // name="file"; l = in.readLine(b, 0, b.length); // String type=new // String(b,0,l);//eg.Content-Type:application/octet-stream(程序文件) l = in.readLine(b, 0, b.length); // String nulll=new String(b,0,l);//此值应为空 int nIndex = info.toLowerCase().indexOf("filename=\""); int nLastIndex = info.toLowerCase().indexOf("\"", nIndex + 10); String filepath = info.substring(nIndex + 10, nLastIndex); int na = filepath.lastIndexOf("\\"); String filename = filepath.substring(na + 1); // out.println("文件绝对路径:"+filepath+"
"); // out.println("文件名:"+filename+"

"); String path=fpath + filename; File fi = new File(path);// 建立目标文件 if (!fi.exists()&&!fi.createNewFile()) return -2; BufferedOutputStream f = new BufferedOutputStream(new FileOutputStream( fi)); while ((l = in.readLine(b, 0, b.length)) > 0) { if (l == sign.length()) { String sign1 = new String(b, 0, sign.length()); // out.println(sign1+"
"); if (sign1.startsWith(sign))// 比对是否文件已传完 break; } f.write(b, 0, l); f.flush(); } f.flush(); f.close(); long end = System.currentTimeMillis();// 传送时间计时结束 // out.println("上传文件用时:"+(end-begin)+"毫秒
"); return end - begin; } }

2. submitFile.jsp:

<%@ page language="java" import="java.util.*" pageEncoding="GB18030"%>
<%
  String path = request.getContextPath();
  String basePath = request.getScheme() + "://"
      + request.getServerName() + ":" + request.getServerPort()
      + path + "/";
%>


  
    
    My JSP 'submitFile.jsp' starting page
    
    
    
    
    
    
    
  
  
    

 

姓名
  文件  
文件类型
 

 

 

3. AnswerFile.jsp:



<%@ page language="java" import="java.util.*,java.io.*"
  pageEncoding="GB18030"%>
<%
  String path = request.getContextPath();
  String basePath = request.getScheme() + "://"
      + request.getServerName() + ":" + request.getServerPort()
      + path + "/";
%>


  
    
    My JSP 'AnswerFile.jsp' starting page
    
    
    
    
    
    
  
  
    
    
    <%
      ServletInputStream in = request.getInputStream();
      upload.setInputStream(in);
      String nam = upload.getParameter();
      out.println("姓名:" + nam + "

"); long time = upload.getFileUpload(); out.println("文件上传完毕,总共耗时:" + time + "毫秒
"); String leixing = upload.getParameter(); out.println("文件类型:" + leixing + "
"); in.close(); %>
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希望本文所述对大家的JSP程序设计有所帮助。

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