关于用session设置属性等有关问题

<%@ page contentType="text/html;charset=gbk"%><%@ page import="java.io.*"%><%!    int temp=0;//问1：为什么temp不能直接定义在load方法的try{}里?如果定义在里面就会出现temp cannot be resolved    int load(File f){//取得count.txt中的访问量    try{        temp=new Integer(new BufferedReader(new InputStreamReader(new FileInputStream(f))).readLine());        }catch(Exception e){e.getMessage();}        return temp;    }    public synchronized void save(int c,File f){//向count.txt中保存访问量        try{                int tem=++c;                session.setAttribute("count",new Integer(tem));//问2：session为何无法被解析？                PrintStream ps=new PrintStream(new FileOutputStream(f));                ps.println(c);                ps.close();        }catch(Exception e){ e.getMessage();}    }%><%    String fileName=getServletContext().getRealPath("/")+"application"+File.separator+"count.txt";    File f=new File(fileName);    int count=load(f);    if(session.isNew())    save(count,f);//如果是一个新的会话，计数器加1%><h1>你是第<%=session.getAttribute("count")%>个访问本站的人！</h1>