JSP实现快速上传文件的方法
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：
packageFileUpload;
importjava.io.BufferedOutputStream;
importjava.io.File;
importjava.io.FileOutputStream;
importjavax.servlet.ServletInputStream;
/**
*
*/
/**
*@authorQch
*
*/
publicclassFileUpload
{
ServletInputStreamin=null;
Stringfpath="C://";
publicFileUpload()
{
fpath="C://";
in=null;
}
publicvoidsetInputStream(ServletInputStreamin)
{
this.in=in;
}
publicvoidsetFpath(Stringp)
{
this.fpath=p;
}
publicStringgetFpath()
{
returnfpath;
}
publicStringgetParameter()
{
Stringr=null;
try
{
r=getParameter(in);
}
catch(Exceptione)
{
e.printStackTrace();
}
returnr;
}
publiclonggetFileUpload()
{
longr=-1;
try
{
r=getFileUpload(in,fpath);
}
catch(Exceptione)
{
e.printStackTrace();
}
returnr;
}
publicStringgetParameter(ServletInputStreamin)//只能按顺序提取
throwsException
{
intl=0;
byte[]b=newbyte[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
Stringsi=newString(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);
Stringvalue=newString(b,0,l);
returnvalue;
}
publiclonggetFileUpload(ServletInputStreamin,Stringfpath)//需要提供输入流和存储路径
throwsException
{
//out.println("文件信息:<br>");
longbegin=System.currentTimeMillis();//传送时间计时开始
intl=0;
byte[]b=newbyte[1024];
l=in.readLine(b,0,b.length);
Stringsign=newString(b,0,l);//eg.-----------------------------7d9dd29630a34
l=in.readLine(b,0,b.length);
Stringinfo=newString(b,0,l);//eg.Content-Disposition:form-data;
//name="file";
l=in.readLine(b,0,b.length);
//Stringtype=new
//String(b,0,l);//eg.Content-Type:application/octet-stream(程序文件)
l=in.readLine(b,0,b.length);
//Stringnulll=newString(b,0,l);//此值应为空
intnIndex=info.toLowerCase().indexOf("filename=\"");
intnLastIndex=info.toLowerCase().indexOf("\"",nIndex+10);
Stringfilepath=info.substring(nIndex+10,nLastIndex);
intna=filepath.lastIndexOf("\\");
Stringfilename=filepath.substring(na+1);
//out.println("文件绝对路径："+filepath+"<br>");
//out.println("文件名："+filename+"<br><br>");
Stringpath=fpath+filename;
Filefi=newFile(path);//建立目标文件
if(!fi.exists()&&!fi.createNewFile())
return-2;
BufferedOutputStreamf=newBufferedOutputStream(newFileOutputStream(
fi));
while((l=in.readLine(b,0,b.length))>0)
{
if(l==sign.length())
{
Stringsign1=newString(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();
longend=System.currentTimeMillis();//传送时间计时结束
//out.println("上传文件用时："+(end-begin)+"毫秒<br>");
returnend-begin;
}
}
2.submitFile.jsp：
<%@pagelanguage="java"import="java.util.*"pageEncoding="GB18030"%>
<%
Stringpath=request.getContextPath();
StringbasePath=request.getScheme()+"://"
+request.getServerName()+":"+request.getServerPort()
+path+"/";
%>
<!DOCTYPEHTMLPUBLIC"-//W3C//DTDHTML4.01Transitional//EN">
<html>
<head>
<basehref="<%=basePath%>">
<title>MyJSP'submitFile.jsp'startingpage</title>
<metahttp-equiv="pragma"content="no-cache">
<metahttp-equiv="cache-control"content="no-cache">
<metahttp-equiv="expires"content="0">
<metahttp-equiv="keywords"content="keyword1,keyword2,keyword3">
<metahttp-equiv="description"content="Thisismypage">
<!--
<linkrel="stylesheet"type="text/css"href="styles.css">
-->
<scriptlanguage="javascript">
functioncheck()
{
if(document.form2.name.value==""){
alert("姓名不能为空！！");
document.form2.name.focus();
returnfalse;
}
if(document.form2.file.value==""){
alert("文件不能为空！！");
returnfalse;
}
returntrue;
}
</script>
</head>
<body>
<br>
<formmethod="post"name="form2"enctype="MULTIPART/FORM-DATA"
action="AnswerFile.jsp">
<br>
<palign="center">
<br>
</p>
<tablewidth="530"border="1"bgcolor="#c0c0c0"align="center"
height="91">
<tbody>
<tr>
<tdvalign="top"align="right">
姓名
<br>
</td>
<tdvalign="top">
<inputtype="text"name="name">
</td>
</tr>
<tr>
<tdalign="right">
文件
</td>
<tdalign="left">
<inputtype="file"name="file">
</td>
</tr>
<tr>
<tdvalign="top"align="right">
文件类型
<br>
</td>
<tdvalign="top"align="left">
<selectsize="1"name="leixing">
<optionselectedvalue="作业">
作业
</option>
<optionvalue="课程设计">
课程设计
</option>
<optionvalue="论文">
论文
</option>
</select>
</td>
</tr>
<tr>
<tdalign="right">
<inputtype="Submit"value="上传"name="button2"onclick="return(check());">
</td>
<tdalign="left">
<inputtype="reset"value="重置"name="button3">
</td>
</tr>
</tbody>
</table>
<p>
<br>
<br>
</p>
</form>
</body>
</html>
3.AnswerFile.jsp：
<%@pagelanguage="java"import="java.util.*,java.io.*"
pageEncoding="GB18030"%>
<%
Stringpath=request.getContextPath();
StringbasePath=request.getScheme()+"://"
+request.getServerName()+":"+request.getServerPort()
+path+"/";
%>
<!DOCTYPEHTMLPUBLIC"-//W3C//DTDHTML4.01Transitional//EN">
<html>
<head>
<basehref="<%=basePath%>">
<title>MyJSP'AnswerFile.jsp'startingpage</title>
<metahttp-equiv="pragma"content="no-cache">
<metahttp-equiv="cache-control"content="no-cache">
<metahttp-equiv="expires"content="0">
<metahttp-equiv="keywords"content="keyword1,keyword2,keyword3">
<metahttp-equiv="description"content="Thisismypage">
<!--
<linkrel="stylesheet"type="text/css"href="styles.css">
-->
</head>
<body>
<jsp:useBeanid="upload"scope="session"class="FileUpload.FileUpload"/>
<jsp:setPropertyname="upload"value="C://"property="fpath"/>
<%
ServletInputStreamin=request.getInputStream();
upload.setInputStream(in);
Stringnam=upload.getParameter();
out.println("姓名:"+nam+"<br><br>");
longtime=upload.getFileUpload();
out.println("文件上传完毕，总共耗时："+time+"毫秒<br>");
Stringleixing=upload.getParameter();
out.println("文件类型："+leixing+"<br>");
in.close();
%>
<br>
<divalign="right">
<ahref="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。