JSP的login程序代码-JSP教程,Jsp/Servlet

<!– login manager –>

<java type="class">

public static boolean checkuserpermission(httpsession mysession, httpservletrequest request, httpservletresponse response)
{

if (mysession.getvalue("haspermission") == null || !((boolean) mysession.getvalue("haspermission")).booleanvalue())
{
string requestedurl = httputils.getrequesturl(request).tostring();
string querystring = request.getquerystring();
if (querystring != null)
{
requestedurl = requestedurl + "?" + querystring;
}
requestedurl = response.encodeurl(requestedurl);
mysession.putvalue("requestedurl", requestedurl);

return false;
}
else
{
return true;
}
}

</java>

<%
// this is a jsp file

string gooduser = "bill";
string goodpass = "bobo";

httpsession mysession = request.getsession(true);

string errormessage = "please login to access the page you requested";

boolean loginattempt = false;

string mymethod = request.getmethod();
if (request.getparametervalues("click") != null && request.getparametervalues("click")[0].trim().equals("log in"))
{
loginattempt = true;
}

if (loginattempt)
{
string username = request.getparametervalues("user")[0].trim();
string password = request.getparametervalues("pass")[0].trim();
//out.println("username = |" + username + "| & password = |" + password + "|<br>");

if (gooduser.equals(username) && goodpass.equals(password))
{
response.sendredirect((string)mysession.getvalue("requestedurl"));
mysession.putvalue("haspermission", new boolean(true));
errormessage = "unable to redirect: " + (string)mysession.getvalue("requestedurl");
}
else
{
errormessage = "you did not get the username or password right";
}

}
else
{
errormessage = "havent tried logging in yet.";
if (mysession.getvalue("requestedurl") == null)
{
mysession.putvalue("requestedurl", "/index.jsp");
}
//out.println("set userreferrer to " + mysession.getvalue("redirectto") + "<br>");
}
%>

<center>
<font color=red><%=errormessage%></font>
<table align=center>
<form action="adminlogin2.jsp" method=post name="login">
<tr><td>username:</td><td><input type=text name=user value=""></td></tr>
<tr><td>password:</td><td><input type=password name=pass value=""></td></tr>
<tr><td colspan=2 align=center><input type=submit name=click value="log in"></td></tr>
</form>

</table>
</center>
original url: <%= (string)mysession.getvalue("requestedurl") %>

<script language="javascript">
// <!–
if (document.forms.login != null)
document.forms.login.user.focus();
// –>
</script>