文件上传问题

大家好，这是我的一个文件上传的jsp程序，老是出错，大虾们帮忙看看啦！
<%@ page contentType="text/html; charset=gb2312" language="java" import="java.sql.*" errorPage="" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<%@ page import="java.util.*"%>
<%@ page import="java.io.*"%>
<%@ page import="javax.servlet.*"%>
<%@ page import="javax.servlet.http.*"%><html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>文件上传界面</title>
</head><body>
<%
int MAX_SIZE=102400;
 String rootPath;
 DataInputStream in=null;
 FileOutPutStream fileOut=null;
 String remoteAddr=request.getRemoteAddr();
 String serverName=request.getServerName();
 String realPath=request.getRealPath(serverName);
 realPath=realPath.substring(0,realPath.lastIndexOf("\\"));
 rootPath=realPath+"\\unload\\";
 Out.println("上传文件保存目录为"+rootPath);
 String  contentType=request.getContentType();
 try
 { 
  if(contentType.indexOf("multipart/forem-data")>=0)
  {
  in=new DataInputStream(request.getInputStream());
  int formDataLength=request.getContentLength();
  if(formDataLength>MAX_SIZE)
  {
  Out.println("<p>上传的文件字节数不可以超过"+MAX_SIZE+"</P>"）;
  return;
  }
  byte dataBytes[]=new byte[formDataLength];
  int byteRead=0;
  int totalBytesRead=0;
  while(totalBytesRead<formDataLength)
  {
  byteRead=in.read(dataBytes,totalBytesRead,formDataLength);
  totalBytesRead+=byteRead;
  }
  String file=new String(dataBytes);
  String saveFile=file.substring(file.indexOf("filename=\"")+10);
  saveFile=saveFile.substring(0,saveFile.indexOf("\n"));
  saveFile=saveFile.substring(saveFile.lastIndexOf("\\")+1,saveFile.indexOf("\""));
  int lastIndex=contentType.lastIndex0f("=");
  String boundary=contentType.substring(lastIndex+1,contentType.length());
  String fileName=rootPath+saveFile;
  int pos;
  pos=file.indexOf("filename=\"");
  pos=file.indexOf("\n",pos)+1;
  pos=file.indexOf("\n",pos)+1;
  pos=file.indexOf("\n",pos)+1;
  int boundaryLocation=file.indexOf(boundary,pos)-4;
  int startPos=((file.substring(0,pos)).getBytes()).length;
  int endPos=((file.substring(0,boundaryLocation)).getBytes()).length;
  File checkFile=new File(fileName);
  if(checkFile.exists())
  {
  out.println("<->"+saveFile+"文件已经存在.</p>");
  File fileDir=new File(rootPath);
  if(!fileDir.exists())
  {
  fileDir.mkdirs();
  }
  FileOut=new FileOutputstream(fileName);
  fileOut.write(dataBytes,startPos,(endPos-startPos));
  fileOut.close();
  Out.println("<p><font color=red size=5>"+saveFile+"文件成功上传！</font></p>");
  }
  }
  else
  {
  String content=request.getContentType();
  Out.println("<p>上传的数据类型不是multipart/form-data</p>");
  }
  }
  catch(Exception ex)
  {
  throw new ServletException(ex.getMessage());
  }
  %>
  <a href="shangchuan.jsp">继续上传文件</a>
  
</body>
</html>
出错信息如下：
type Exception reportmessage description The server encountered an internal error () that prevented it from fulfilling this request.exception org.apache.jasper.JasperException: Unable to compile class for JSP: An error occurred at line: 19 in the jsp file: /file.jsp
FileOutPutStream cannot be resolved to a type
16: int MAX_SIZE=102400;
17:  String rootPath;
18:  DataInputStream in=null;
19:  FileOutPutStream fileOut=null;
20:  String remoteAddr=request.getRemoteAddr();
21:  String serverName=request.getServerName();
22:  String realPath=request.getRealPath(serverName);
An error occurred at line: 15 in the jsp file: /file.jsp
Out cannot be resolved
12: </head>
13: 
14: <body>
15: <%
16: int MAX_SIZE=102400;
17:  String rootPath;
18:  DataInputStream in=null;
An error occurred at line: 15 in the jsp file: /file.jsp
Out cannot be resolved
12: </head>
13: 
14: <body>
15: <%
16: int MAX_SIZE=102400;
17:  String rootPath;
18:  DataInputStream in=null;
An error occurred at line: 15 in the jsp file: /file.jsp
Syntax error on token "Invalid Character", ) expected
12: </head>
13: 
14: <body>
15: <%
16: int MAX_SIZE=102400;
17:  String rootPath;
18:  DataInputStream in=null;
An error occurred at line: 50 in the jsp file: /file.jsp
The method lastIndex0f(String) is undefined for the type String
47:   String saveFile=file.substring(file.indexOf("filename=\"")+10);
48:   saveFile=saveFile.substring(0,saveFile.indexOf("\n"));
49:   saveFile=saveFile.substring(saveFile.lastIndexOf("\\")+1,saveFile.indexOf("\""));
50:   int lastIndex=contentType.lastIndex0f("=");
51:   String boundary=contentType.substring(lastIndex+1,contentType.length());
52:   String fileName=rootPath+saveFile;
53:   int pos;
An error occurred at line: 70 in the jsp file: /file.jsp
FileOut cannot be resolved
67:   {
68:   fileDir.mkdirs();
69:   }
70:   FileOut=new FileOutputstream(fileName);
71:   fileOut.write(dataBytes,startPos,(endPos-startPos));
72:   fileOut.close();
73:   Out.println("<p><font color=red size=5>"+saveFile+"文件成功上传！</font></p>");
An error occurred at line: 70 in the jsp file: /file.jsp
FileOutputstream cannot be resolved to a type
67:   {
68:   fileDir.mkdirs();
69:   }
70:   FileOut=new FileOutputstream(fileName);
71:   fileOut.write(dataBytes,startPos,(endPos-startPos));
72:   fileOut.close();
73:   Out.println("<p><font color=red size=5>"+saveFile+"文件成功上传！</font></p>");
An error occurred at line: 15 in the jsp file: /file.jsp
Out cannot be resolved
12: </head>
13: 
14: <body>
15: <%
16: int MAX_SIZE=102400;
17:  String rootPath;
18:  DataInputStream in=null;
An error occurred at line: 15 in the jsp file: /file.jsp
Out cannot be resolved
12: </head>
13: 
14: <body>
15: <%
16: int MAX_SIZE=102400;
17:  String rootPath;
18:  DataInputStream in=null;
Stacktrace:
org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:85)
org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:330)
org.apache.jasper.compiler.JDTCompiler.generateClass(JDTCompiler.java:415)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:308)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:286)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:273)
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:566)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:308)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
note The full stack trace of the root cause is available in the Apache Tomcat/6.0.10 logs.