Shop/src/filters/SessionFilter.java

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package filters;

import java.io.IOException;
import javax.servlet.*;
import javax.servlet.http.*;

public class SessionFilter extends HttpServlet
    implements Filter
{

    private static final long serialVersionUID = 1L;
    private FilterConfig filterConfig;

    public SessionFilter()
    {
    }

    public void init(FilterConfig filterConfig)
        throws ServletException
    {
        this.filterConfig = filterConfig;
    }

    public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain)
        throws IOException
    {
        HttpServletResponse response1;
        String username;
        HttpServletRequest request1 = (HttpServletRequest)request;
        response1 = (HttpServletResponse)response;
        HttpSession session = request1.getSession();
        username = (String)session.getAttribute("username");
        if(username == null || "".equals(username))
        {
            response1.sendRedirect("/login.jsp");
            return;
        }
        try
        {
            filterChain.doFilter(request, response);
        }
        catch(Exception sx)
        {
            filterConfig.getServletContext().log(sx.getMessage());
        }
        return;
    }

    public void destroy()
    {
    }
}