使用JAVA技术实现文件的上传

作者：ztyzty
下面是一个用来上传下达的小程序,希望大家给予指教.
import JAVA.io.*;
import JAVA.util.*;
import JAVA.text.*;
import JAVAx.mail.*;
import JAVAx.servlet.*;
import JAVAx.activation.*;
import JAVAx.servlet.http.*;
import JAVAx.mail.internet.*;
import JAVAx.mail.internet.MimeMultipart;
/**
*@author2002/7/10 zty
*
*
* 【使用例】
* try {
* Upload load=new Upload();
* load.setDir("i://ztytest//"); * load.doUpload(req,res); *//HttpServletRequest req
*//HttpServletResponse res
* }
* catch( Exception e ) {
* return;
* }
*/
public class Upload extends HttpServlet {
public String strDir;
public Upload()
{
}
public void doUpload(HttpServletRequest req, HttpServletResponse res)
throws IOException,MessagingException
{
String boundary=req.getHeader("Content-Type");
int pos=boundary.indexOf('=');
boundary=boundary.substring(pos+1);
boundary="--"+ boundary;
ServletInputStream in=req.getInputStream() ;
byte[] bytes=new byte[512];
int state=0;
ByteArrayOutputStream buffer=new ByteArrayOutputStream();
String name=null;
String value=null;
String filename=null;
String contentType=null;
int i=in.readLine(bytes,0,512);
while (-1!=i)
{
String st=new String(bytes,0,i);
if (st.startsWith(boundary))
{
state=0;
System.out.println(filename);
if (null!=name)
{
if(buffer.size()>2)
{
FileOutputStream outStream = new FileOutputStream(strDir+filename);
outStream.write(buffer.toByteArray(), 0, buffer.toByteArray().length);
outStream.close();
}
name=null;
value=null;
filename=null;
contentType=null;
buffer=new ByteArrayOutputStream();
}
}//end of st.startsWith(boundary)
else if (st.startsWith("Content-Disposition: form-data") && state==0)
{
StringTokenizer tokenizer=new StringTokenizer(st,";=/"");
while(tokenizer.hasMoreTokens())
{
String token=tokenizer.nextToken();
if(token.trim().startsWith("name"))
{
name=tokenizer.nextToken();
state=2;
}
else if(token.trim().startsWith("filename"))
{
filename=tokenizer.nextToken();
StringTokenizer ftokenizer=new StringTokenizer(filename,"//");
filename=ftokenizer.nextToken();
while(ftokenizer.hasMoreTokens())
filename=ftokenizer.nextToken();
state=1;
break;
}
}
}//end state=0
else if (st.startsWith("Content-Type") && state==1)
{
pos=st.indexOf(":");
contentType=st.substring(pos+2,st.length()-2);
}//end state=1
else if (state==1)
state=3;
else if (st.equals("/r/n")&&state==2)
state=4;
else if (state==3)
buffer.write(bytes,0,i);
else if (state==4)
value=value==null?st:value+st;
i=in.readLine(bytes,0,512);
}//end while
}
public void setDir(String strSavePath)
{
strDir =strSavePath;
}
class ByteDataSource implements DataSource
{
byte[] bytes;
String contentType;
String name;
ByteDataSource(byte[] bytes,String contentType,String name)
{
this.bytes=bytes;
this.contentType=contentType;
this.name=name;
}
public String getContentType()
{
return contentType;
}
public InputStream getInputStream()
{
return new ByteArrayInputStream(bytes,0,bytes.length-2);
}
public String getName()
{
return name;
}
public OutputStream getOutputStream() throws IOException
{
throw new FileNotFoundException();
}
}//end of class
}