package mypackage;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletResponse;
import org.apache.catalina.connector.Request;
import org.apache.catalina.connector.Response;
import org.apache.catalina.Globals;
import org.apache.catalina.valves.ValveBase;

public class MyErrorValve extends ValveBase{
    
    
    /**
     * Invoke the next Valve in the sequence. When the invoke returns, check
     * the response state, and output an error report is necessary.
     *
     * @param request The servlet request to be processed
     * @param response The servlet response to be created
     *
     * @exception IOException if an input/output error occurs
     * @exception ServletException if a servlet error occurs
     */
    public void invoke(Request request, Response response)
        throws IOException, ServletException {

        // Perform the request
        getNext().invoke(request, response);

        ServletRequest sreq = (ServletRequest) request;
        Throwable throwable =
            (Throwable) sreq.getAttribute(Globals.EXCEPTION_ATTR);

        ServletResponse sresp = (ServletResponse) response;
        if (sresp.isCommitted()) {
            return;
        }

        if (throwable != null) {

            // The response is an error
            response.setError();

            // Reset the response (if possible)
            try {
                sresp.reset();
            } catch (IllegalStateException e) {
                ;
            }

            response.sendError
                (HttpServletResponse.SC_INTERNAL_SERVER_ERROR);

        }

        response.setSuspended(false);

// The difference from ErrorReportValve is that we don't return a report
// in the response.
//        try {
//            report(request, response, throwable);
//        } catch (Throwable tt) {
//            tt.printStackTrace();
//        }

    }
    
    
    
}