求文件上传类

本人觉的文件上传无分就是分解字符串的东西
以下是文件上传的一个类
package UploadFile;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;public class UploadFileServlet extends HttpServlet{
public void doPost(HttpServletRequest req,HttpServletResponse res)throws ServletException,IOException{
final int NONE=0;             //×´Ì¬ÂëÊ,±íÊ¾Ã»ÓÐÌØÊâ²Ù×÷
final int DATAHEADER=1;       //±íÊ¾ÏÂÒ»ÐÐÒª¶Áµ½±¨Í·µÄÐÅÏ¢
final int FILEDATA=2;         //±íÊ¾ÏÂÃæÒª¶Áµ½±íµ¥ÓòµÄÎÄ±¾Öµ
final int FIELDDATA=3;        //±íÊ¾ÏÂÃæÒª¶ÁµÄÊÇÉÏ´«ÎÄ¼þºÍ¶þ½øÖÆÊý¾Ý
//ÇëÇóÏûÏ¢ÊµÌåµÄ×Ü³¤¶È(ÇëÇóÏûÏ¢ÖÐ³ýÏûÏ¢Í·Ö®ÍâµÄÊý¾Ý³¤¶È
int totalbytes=req.getContentLength();
//ÈÝÄÉÇëÇóÏûÏ¢Êµ¼ÊµÄ×Ö½ÚÊý×é
byte[]b=new byte[totalbytes];

//ÇëÇóÏûÏ¢ÀàÐÍ
String contentType=req.getContentType();
String fieldname="";           //±íµ¥ÓòµÄÃû³Æ
String fieldvalue="";          //±íµ¥ÓòµÄÖµ
String filename="";            //ÉÏ´«µÄÎÄ¼þÃû³Æ
String boundary="";            //·Ö½ç·û×Ö·û´®
String lastboundary="";        //½áÊø·Ö½ç·û×Ö·û´®
int fileSize=0;                //ÎÄ¼þ³¤¶È
//String strContentName="";       //Ã¿Ò»´Î¶ÁÈ¡Êý¾ÝÏîÊ±¼Ç×¡ÕâÒ»×Ö·û
//ÈÝÄÉ±íµ¥ÓòµÄÃû³Æ/ÖµµÄ¹þÏ£±í
Hashtable formfields=new Hashtable();
//ÔÚÏûÏ¢Í·ÀàÐÍÖÐÕÒµ½·Ö½ç·ûµÄ¶¨Òå
int pos=contentType.indexOf("boundary=");
String fileID;                  //ÉÏ´«µÄÎÄ¼þID
if(pos!=-1){
pos+="boundary=".length();
boundary="--" + contentType.substring(pos);  //½âÎö³ö·Ö½ç·û
lastboundary=boundary+"--";                  //µÃµ½½áÊø·Ö½ç·û
}
int state=NONE;                //ÆðÊ¼×´Ì¬ÎªNONE
//µÃµ½ÇëÇóÏûÏ¢µÄÊý¾ÝÊäÈëÁ÷
DataInputStream in=new DataInputStream(req.getInputStream());
in.readFully(b);               //¸ù¾Ý³¤¶È,½«ÏûÏ¢ÊµÌåµÄÄÚÈÝ¶ÁÈëÊý×ébÖÐ
in.close();                    //¹Ø±ÕÊý¾ÝÁ÷
String reqcontent=new String(b); //´Ó×Ö½ÚÊý×éÖÐµÃµ½±íÊ¾ÊµÌåµÄ×Ö·û´®
//´Ó×Ö·û´®ÖÐµÃµ½Êä³ö»º³åÁ÷
BufferedReader reqbuf=new BufferedReader(new StringReader(reqcontent));

解决方案 »

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//ÉèÖÃÑ»·±êÖ¾
boolean flag=true;
int i=0;
while(flag==true){
    String s=reqbuf.readLine();
    if(s==lastboundary||s==null) break;
    switch(state){
     case NONE:
     if(s.startsWith(boundary)){
     state=DATAHEADER;
     i+=1;
     }
     break;
     case DATAHEADER:
         pos=s.indexOf("filename=");
         if(pos==-1){
          pos=s.indexOf("name=");
         // strContentName=s;
          pos+="name=".length()+1;
          s=s.substring(pos);
          int l=s.length();
          s=s.substring(0,l-1);
          fieldname=s;
          state=FIELDDATA;
         }
         else{
          String temp=s;
          pos=s.indexOf("filename=");
          pos+="filename=".length()+1;
          s=s.substring(pos);
          int l=s.length();
          s=s.substring(0,l-1);
          pos=s.lastIndexOf("\\");
          s=s.substring(pos+1);
          filename=s;
             if (filename.equals("")){state=FILEDATA;break;}
          pos=byteIndexOf(b,temp,0);
         // b=subBytes(b,pos+temp.getBytes().lenght+2,b.lenght);
             b=subBytes(b,pos+temp.getBytes().length+2,b.length);
          s=reqbuf.readLine();

          File f=new File(getServletContext().getRealPath("/") + "upload/" + filename);
          DataOutputStream fileout=new DataOutputStream(new FileOutputStream(f));
          b=subBytes(b,s.getBytes().length+4,b.length);
          pos=byteIndexOf(b,boundary,0);
          b=subBytes(b,0,pos-1);
          fileout.write(b,0,b.length-1);
          fileout.close();
          fileSize=b.length-1;
          state=FILEDATA;
         }
         break;
     case FIELDDATA:

         //byte[] bytemp=b;
         //pos=byteIndexOf(bytemp,strContentName,0);
         //bytemp=subBytes(bytemp,pos+strContentName.getBytes().length+4,bytemp.length);
         //pos=byteIndexOf(bytemp,boundary,0);
         //bytemp=subBytes(bytemp,0,pos-1);
         //fieldvalue=bytemp.toString();
         s=reqbuf.readLine();
         fieldvalue=s;
         while((!s.startsWith(boundary)) && (!s.startsWith(lastboundary))){
            s=reqbuf.readLine();
            if (s.startsWith(boundary)) break;
            fieldvalue=fieldvalue + "\r\n" + s;

         }
         formfields.put(fieldname,fieldvalue);
         state=DATAHEADER;
         break;
     case FILEDATA:
     while((!s.startsWith(boundary)) && (!s.startsWith(lastboundary))){
     s=reqbuf.readLine();
     if (s.startsWith(boundary)){
     state=DATAHEADER;
     break;
     }
     //else break;
     }
     break;
     }
}

res.setContentType("text/html;charset=gb2312");
PrintWriter out=res.getWriter();
out.println("<html><head><title>ÎÄ¼þÉÏ´«½á¹û</title></head><body><h1>ÎÄ¼þÉÏ´«½á¹û</h1><br>");
out.println("IDÎª" + formfields.get("FileID")+"µÄÎÄ¼þ"+filename+"ÒÑ¾ÉÏ´«!"+"ÎÄ¼þ³¤¶ÈÎª:"+fileSize+"×Ö½Ú");
out.println("<p>MessageÎª" + formfields.get("Message")+"</p>");
out.println("<p>ÉÏ´«µÄÎÄ¼þµØÖ·:<a href=\"/Forums/upload/" + filename +"\">²é¿´</a></p>");
// out.println("<p>OrderÎª" + formfields.get("Order")+"µÄÎÄ¼þ</p>");
out.println("</body></html>");
}

private static int byteIndexOf(byte[]b,String s,int start){
return byteIndexOf(b,s.getBytes(),start);
}
private static int byteIndexOf(byte[]b,byte[]s,int start){
int i;
if(s.length==0){
return 0;
}
int max=b.length-s.length;
if(max<0)
return -1;
if(start>max)
return -1;
if(start<0)
    start=0;
search:
     for(i=start;i<=max;i++){
      if(b[i]==s[0]){
      int k=1;
      while(k<s.length){
      if(b[k+i]!=s[k]){
      continue search;
      }
      k++;
      }
      return i;
      }
     }
return -1;
    }
private static byte[] subBytes(byte[] b,int from,int end){
byte[] result=new byte[end-from];
System.arraycopy(b,from,result,0,end-from);
return result;
}
private static String subBytesString(byte[] b,int from,int end){
return new String(subBytes(b,from,end));
}

}