package myitem.renshu;

import javax.servlet.Filter;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.FilterChain;
import java.io.IOException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.ArrayList;
import javax.servlet.http.HttpSession;
import java.util.StringTokenizer;

public class StatFilter
    implements Filter {
    public StatFilter() {
    }

    public void init(FilterConfig filtercfg) throws javax.servlet.
        ServletException {
    }

    public void doFilter(ServletRequest request,
                         ServletResponse response,
                         FilterChain filterchain) throws java.io.IOException,
        javax.servlet.ServletException {
        HttpServletRequest httpRequest = (HttpServletRequest) request;
        HttpSession session = httpRequest.getSession(true);
        if (session.getAttribute("isRecorded") == null) {
            //如果本次用戶訪問還沒有記錄，就記錄本次用戶信息，并保存到數據庫中
            session.setAttribute("isRecorded", Boolean.TRUE);
            //在session對象中保存一個變量"isRecorded"，并賦值
            String ip = httpRequest.getRemoteAddr();
            //從請求頭中取出客戶端IP地址
            String agent = httpRequest.getHeader("User-Agent");
            System.out.println("HTTP-HEAD: ");
            System.out.println(agent);
            //從請求頭中讀取User-Agent值
            StringTokenizer st = new StringTokenizer(agent, ";)");
            //構造StringTokenizer對象，使用“；”“）”來分解User-Agent值
            st.nextToken();
            String browser = st.nextToken();
            //得到用戶的瀏覽器名
            String os = st.nextToken();
            //得到用戶的操作系統名
            if (ip == null) {
                ip = "未知";
                //如果讀取的IP為空，則賦值為“未知”
            }
            if (browser == null) {
                browser = "未知";
                //如果讀取的瀏覽器名為空，則賦值為“未知”
            }
            if (os == null) {
                os = "未知";
                //如果讀取的操作系統名為空，則賦值為“未知”
            }
            try {
                StatHandle.insert(ip, os.trim(), browser.trim());
                //調用業務邏輯，將用戶數據插入到數據庫中
            }
            catch (Exception es) {
                es.printStackTrace();
                //在輸入日志中打印異常信息
            }
        }
        filterchain.doFilter(request, response);
        //調用下一個過濾器或者直接調用JSP
    }


    public void destroy()
    {
    	
    }
}