取得session
HttpSession session=request.getSession() ;
向session中存数据
session.setAttribute("dataId",new Object());
读session中数据
Object temp=session.getAttribute("dataId");
HttpSession session=request.getSession() ;
向session中存数据
session.setAttribute("dataId",new Object());
读session中数据
Object temp=session.getAttribute("dataId");
import javax.servlet.http.*;
import java.io.*;
import java.util.*;public class testServlet extends HttpServlet { private static final String CONTENT_TYPE = "text/html; charset=GBK";
//Initialize global variables public HttpSession session;
public void init() throws ServletException {
} //Process the HTTP Get request
public void doGet(HttpServletRequest request, HttpServletResponse response) throws
ServletException, IOException { response.setContentType(CONTENT_TYPE);
PrintWriter out = response.getWriter(); //通过request初始化session
session = request.getSession(); out.println("<html>");
out.println("<head><title>testServlet</title></head>");
out.println("<body bgcolor=\"#ffffff\">"); getRs(); out.print("<script language = \"JavaScript\">function KDG_ChangePage(frmName){var frmObj = eval(\"document.\"+frmName);frmObj.submit();}</script>");
out.println("</body></html>");
} /**
* 处理初次进入页面时要初始化的变量
*/
public void getRs(){ //利用session中的isFirst判断是否第一次进入此页面。
if (session.getAttribute("isFirst") == null) {
System.out.println("初始化变量");
session.setAttribute("isFirst", "1");
}
else{
System.out.println("变量已经进行初始化");
}
} //Process the HTTP Post request
public void doPost(HttpServletRequest request, HttpServletResponse response) throws
ServletException, IOException {
doGet(request, response);
} //Clean up resources
public void destroy() { }
}为什么每次刷新页面的时候，服务器段打印的都是“初始化变量”？？？
HttpSession session=request.getSession() ;
向session中存数据
session.setAttribute("dataId",new Object());
读session中数据
Object temp=session.getAttribute("dataId");
hashtable,有一个主键,然有有一个置
HttpSession session=request.getSession(false) ;
向session中存数据
key ="xxxxx";
session.setAttribute(key, new MUMUOBJ());
读session中数据
MUMUOBJtemp=(MUMUOBJ)session.getAttribute(key);key:一般定义成常量，使用晚了，必须session.remove(key);