如果重新加载（view_blog_comment）页面后如何永久保存会话变量的值？
我正在研究一个主要项目（使用语言java）...其中我有模块（博客）。博客的工作是......当我们点击主页上的链接时...即。博客... blog.jsp页面开放...然后有3个链接 - 1.创建博客 2.查看其他博客 3.查看自己的博客
当我们点击查看其他博客...在那个（viewOtherBlog.jsp）页面我们可以查看所有其他博客...有标题和内容...我已经将标题作为这样的超链接... 博客标题 - ＆gt; ＆＃34;＆gt;＆lt;％= rs.getString（2）％＆gt;
当我们点击这个标题时，我们跳转到另一个页面..我们得到详细的博客视图。跳转到新页面后，我们获得有关该博客的详细信息...可以选择评论博客和发表评论也可以在下面查看。
所有事情都写到...评论帖子按钮没有被点击... 单击按钮时....页面重新加载..页面重新加载后 - 标题和内容详细信息将丢失。
（view_Blog.jsp）
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@page import='java.sql.*'%>
<%
HttpSession s=request.getSession();
String uid=(String)s.getAttribute("u_id");
Class.forName("com.mysql.jdbc.Driver");
Connection conn=DriverManager.getConnection("jdbc:mysql:
//localhost:3306/major_db","root", "root");
%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
<%
try
{
PreparedStatement p1=conn.prepareStatement("select * from blog where pid != '"+uid+"' ");
ResultSet rs=p1.executeQuery();
%>
<% while(rs.next()==true)
{
%>
<table>
<tr>
<td>Blog Author --></td>
<td>
<%=rs.getString(5)%>
</td>
</tr>
<tr>
<td>Blog title --></td>
<td><a href="blog_read_comment.jsp?bid=<%=rs.getInt(1)%>"><%=rs.getString(2) %></td>
//when above link is clicked the value is stored in bid
</tr>
<tr>
<td>Blog Content --></td>
<td><%=rs.getString(3)%></td>
</tr>
<%
}
}
catch(Exception e)
{
out.println(e);
}
%>
</table>
</body>
</html>
</table>
</body>
</html>
（read_blog_comment.jsp）
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@page import='java.io.PrintWriter' %>
<%@page import='java.sql.*'%>
<%@page import="java.util.*" %>
<%@page import='javax.servlet.http.HttpSession' %>
<%
String b_id=request.getParameter("bid");//value of bid is stored in b_id
HttpSession s=request.getSession();//session is created to ]
//permanently save the value of bid
s.setAttribute("b_id",b_id);
String bid=(String)s.getAttribute("b_id");
problem is in above 4 lines....
//value of bid
//is lost when page gets reloaded
//i am not able to understand why this happens
//becoz of this problem when i comment on the blog the blog_name,blog_content is lost
Class.forName("com.mysql.jdbc.Driver");
Connection conn =DriverManager.getConnection("jdbc:mysql://localhost:3306/major_db", "root", "root");
%>
<%
try
{
PreparedStatement p1=conn.prepareStatement("select * from
blog where bid='"+bid+"';");
ResultSet rs=p1.executeQuery();
%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>JSP Page</title>
</head>
<body>
<table>
<% if(rs.next()==true)
{
%>
<tr>
<td><h4>Blog title</h4></td>
</tr>
<tr>
<td><%=rs.getString(2) %></td>
</tr>
<tr>
<td><h4>Blog Content</h4></td>
</tr>
<tr>
<td><%=rs.getString(3)%></td>
</tr>
<%
}
}
catch(Exception e)
{
out.println("Exception"+e);
}
%>
</table>
<form action="blog_Comment_Servlet" method="post">
<h3> Post a Comment </h3>
<textarea name="post_comment" required="required"
id="post-comment" rows="3" cols="50">
</textarea>
<input type="submit" id="button-submit" value="Post" name="submit" />
</form>
<%
try
{
PreparedStatement p1=conn.prepareStatement("select * from
blog_comment where bid='"+bid+"';");
ResultSet rs=p1.executeQuery();
%>
<table border="0">
<label>Comments:</label>
<%
while(rs.next())
{
%>
<tr>
<td><h4>By-</h4></td>
</tr>
<tr>
<td><%=rs.getString(6) %></td>
<td><%=rs.getString(5) %></td>
</tr>
<tr>
<td><h4>Comment - </h4></td>
</tr>
<tr>
<td><%=rs.getString(4)%></td>
</tr>
<%
}
}
catch(Exception e)
{
out.println("Exception - "+e);
}
%>
</table>
</body>
</html>
（blog_comment_servlet编码）
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@page import='java.io.PrintWriter' %>
<%@page import='java.sql.*'%>
<%@page import="java.util.*" %>
<%@page import='javax.servlet.http.HttpSession' %>
<%
String b_id=request.getParameter("bid");
HttpSession s=request.getSession();
s.setAttribute("b_id",b_id);
String bid=(String)s.getAttribute("b_id");
Class.forName("com.mysql.jdbc.Driver");
Connection conn =DriverManager.getConnection("jdbc:mysql:
//localhost:3306/major_db", "root", "root");
%>
<%
try
{
PreparedStatement p1=conn.prepareStatement("select * from
blog where bid='"+bid+"';");
ResultSet rs=p1.executeQuery();
%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>JSP Page</title>
</head>
<body>
<table>
<% if(rs.next()==true)
{
%>
<tr>
<td><h4>Blog title</h4></td>
</tr>
<tr>
<td><%=rs.getString(2) %></td>
</tr>
<tr>
<td><h4>Blog Content</h4></td>
</tr>
<tr>
<td><%=rs.getString(3)%></td>
</tr>
<%
}
}
catch(Exception e)
{
out.println("Exception"+e);
}
%>
</table>
<form action="blog_Comment_Servlet" method="post">
<h3> Post a Comment </h3>
<textarea name="post_comment" required="required"
id="post-comment" rows="3" cols="50">
</textarea>
<input type="submit" id="button-submit" value="Post" name="submit" />
</form>
<%
try
{
PreparedStatement p1=conn.prepareStatement("select * from
blog_comment where bid='"+bid+"';");
ResultSet rs=p1.executeQuery();
%>
<table border="0">
<label>Comments:</label>
<%
while(rs.next())
{
%>
<tr>
<td><h4>By-</h4></td>
</tr>
<tr>
<td><%=rs.getString(6) %></td>
<td><%=rs.getString(5) %></td>
</tr>
<tr>
<td><h4>Comment - </h4></td>
</tr>
<tr>
<td><%=rs.getString(4)%></td>
</tr>
<%
}
}
catch(Exception e)
{
out.println("Exception - "+e);
}
%>
</table>
</body>
</html>