我遇到的一个filter问题
filter代码如下：
package util;

import java.io.IOException;
import javax.servlet.http.*;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServlet;

public class AdminFilter extends HttpServlet implements Filter
{
/**
*
*/
private static final long serialVersionUID = -5545950069282900798L;
protected FilterConfig filterConfig;
String LOGIN_PAGE= "Login.jsp ";
public void doFilter(final ServletRequest req, final ServletResponse res,final FilterChain chain)
throws IOException, ServletException
{
// TODO 自动生成方法存根
HttpServletRequest hreq=(HttpServletRequest)req;
HttpServletResponse hres=(HttpServletResponse)res;
HttpSession session=hreq.getSession();
String flag= " ";
try
{
flag=(String)session.getAttribute( "isLogin ");
if( "true ".equals(flag))
{
chain.doFilter(hreq, hres);
}
else
{
hres.sendRedirect(LOGIN_PAGE);
}
}
catch(Exception e)
{
e.printStackTrace();
}
}

public void init(FilterConfig config) throws ServletException
{
// TODO 自动生成方法存根
this.filterConfig=config;
}

public void setFilterConfig(FilterConfig filterConfig)
{
this.filterConfig=filterConfig;
}

public void destroy()
{
this.filterConfig=null;
}

}


XML中配置如下：

<servlet>
<description> AdminFilter </description>
<display-name> AdminFilter </display-name>
<servlet-name> AdminFilter </servlet-name>
<servlet-class> util.AdminFilter </servlet-class>
</servlet>

<servlet-mapping>
<servlet-name> AdminFilter </servlet-name>
<url-pattern> /admin/* </url-pattern>
</servlet-mapping>

我现在通过http://localhost/Infosite/Login.jsp登入到http://localhost/Infosite/admin/admin_.jsp，总是出现一下错误：

HTTP Status 405 - HTTP method GET is not supported by this URL

我尝试了/admin/下的其他页面登入，都出现相同错误。于是我将配置改成如下：

<servlet-mapping>
<servlet-name> AdminFilter </servlet-name>
<url-pattern> /admin/admin_.jsp </url-pattern>
</servlet-mapping>

这时访问/admin_.jsp出错，/admin/下的其他页面可以访问！

我现在要实现/admin/下的所有页面过滤，应该怎么做？


[解决办法]
hres.sendRedirect(LOGIN_PAGE);

这里是否正确？？