source: SRUAggregator/trunk/src/main/java/eu/clarin/sru/fcs/aggregator/app/ErrorHandler.java @ 6123

package eu.clarin.sru.fcs.aggregator.app;

import com.fasterxml.jackson.databind.ObjectMapper;
import java.io.IOException;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.eclipse.jetty.http.HttpMethod;
import org.eclipse.jetty.server.Request;
import org.slf4j.LoggerFactory;

/**
 *
 * @author edima
 */
public class ErrorHandler extends org.eclipse.jetty.server.handler.ErrorHandler {

        private static final org.slf4j.Logger log = LoggerFactory.getLogger(Aggregator.class);

        private final String redirectRoute = "/index.html";

        @Override
        public void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException {
                // On 404 page we need to show index.html and let JS router do the work, otherwise show error page
                if (response.getStatus() == HttpServletResponse.SC_NOT_FOUND) {
                        forward(redirectRoute, baseRequest, response);
                } else if (request.getMethod().equals("POST")
                                && response.getStatus() == HttpServletResponse.SC_METHOD_NOT_ALLOWED
                                && request.getParameterValues("x-aggregation-context") != null) {

                        // this request must come from VLO
                        String[] queryValues = request.getParameterValues("query");
                        if (queryValues != null && queryValues.length > 0) {
                                baseRequest.getSession().setAttribute("query", queryValues[0]);
                        }

                        String[] contextValues = request.getParameterValues("x-aggregation-context");
                        if (contextValues != null && contextValues.length > 0) {
                                baseRequest.getSession().setAttribute("x-aggregation-context", contextValues[0]);
                        }

                        baseRequest.setMethod(HttpMethod.GET, HttpMethod.GET.asString());

                        forward(redirectRoute, baseRequest, response);
                } else {
                        super.handle(target, baseRequest, request, response);
                }
        }

        void forward(String target, Request request, HttpServletResponse response) throws IOException {
                RequestDispatcher dispatcher = request.getRequestDispatcher(target);
                if (dispatcher != null) {
                        try {
                                response.reset();
                                dispatcher.forward(request, response);
                        } catch (ServletException e) {
                                super.handle(target, request, request, response);
                        }
                } else {
                        log.error("Can not find internal redirect route '" + target + "' while handling error. Will show system error page");
                        super.handle(target, request, request, response);
                }
        }
}