JSP实现快速上传文件的方法-侯体宗的博客

JSP实现快速上传文件的方法
Java / 管理员发布于 7年前 177

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:<br>");    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+"<br>");    // out.println("文件名："+filename+"<br><br>");    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+"<br>");        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<br>");    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 + "/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>    <base href="https:/article/<%=basePath%>">    <title>My JSP 'submitFile.jsp' starting page</title>    <meta http-equiv="pragma" content="no-cache">    <meta http-equiv="cache-control" content="no-cache">    <meta http-equiv="expires" content="0">    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">    <meta http-equiv="description" content="This is my page">    <!--  <link rel="stylesheet" type="text/css" href="https:/article/styles.css">  -->    <script language="javascript">      function check()      {        if (document.form2.name.value==""){          alert("姓名不能为空！！");          document.form2.name.focus();          return false;        }        if (document.form2.file.value==""){          alert("文件不能为空！！");          return false;        }        return true;      }    </script>  </head>  <body>    <br>    <form method="post" name="form2" enctype="MULTIPART/FORM-DATA"      action="AnswerFile.jsp">      <br>      <p align="center">                 <br>      </p>      <table width="530" border="1" bgcolor="#c0c0c0" align="center"        height="91">        <tbody>          <tr><td valign="top" align="right">  姓名  <br></td><td valign="top">  <input type="text" name="name"></td>          </tr>          <tr><td align="right">    文件</td><td align="left">     <input type="file" name="file"></td>          </tr>          <tr><td valign="top" align="right">  文件类型  <br></td><td valign="top" align="left">  <select size="1" name="leixing">    <option selected value="作业">      作业    </option>    <option value="课程设计">      课程设计    </option>    <option value="论文">      论文    </option>  </select></td>          </tr>          <tr><td align="right">  <input type="Submit" value="上传" name="button2" onclick="return(check());"></td><td align="left">     <input type="reset" value="重置" name="button3"></td>          </tr>        </tbody>      </table>      <p>                 <br>        <br>               </p>    </form>  </body></html>

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 + "/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>    <base href="https:/article/<%=basePath%>">    <title>My JSP 'AnswerFile.jsp' starting page</title>    <meta http-equiv="pragma" content="no-cache">    <meta http-equiv="cache-control" content="no-cache">    <meta http-equiv="expires" content="0">    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">    <meta http-equiv="description" content="This is my page">    <!--  <link rel="stylesheet" type="text/css" href="https:/article/styles.css">  -->  </head>  <body>    <jsp:useBean id="upload" scope="session" class="FileUpload.FileUpload"/>    <jsp:setProperty name="upload" value="C://" property="fpath"/>    <%      ServletInputStream in = request.getInputStream();      upload.setInputStream(in);      String nam = upload.getParameter();      out.println("姓名:" + nam + "<br><br>");      long time = upload.getFileUpload();      out.println("文件上传完毕，总共耗时：" + time + "毫秒<br>");      String leixing = upload.getParameter();      out.println("文件类型：" + leixing + "<br>");      in.close();    %>    <br>    <div align="right">      <a href="https:/article/index.jsp">回到首页</a>    </div>  </body></html>

希望本文所述对大家的JSP程序设计有所帮助。

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