CustomExceptionMapper.java

/*
 * RHQ Management Platform
 * Copyright (C) 2005-2013 Red Hat, Inc.
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
 */
package org.rhq.enterprise.server.rest;

import java.lang.reflect.UndeclaredThrowableException;

import javax.ejb.EJBException;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.HttpHeaders;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;
import javax.ws.rs.ext.ExceptionMapper;
import javax.ws.rs.ext.Provider;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.rhq.enterprise.server.authz.PermissionException;
import org.rhq.enterprise.server.resource.ResourceNotFoundException;
import org.rhq.enterprise.server.resource.ResourceTypeNotFoundException;
import org.rhq.enterprise.server.resource.group.ResourceGroupNotFoundException;
import org.rhq.enterprise.server.rest.domain.RHQErrorWrapper;

/**
 * Map a NotFoundException to a HTTP response with respective error message
 * @author Heiko W. Rupp
 */
@Provider
public class CustomExceptionMapper implements ExceptionMapper<Exception> {

    @Context
    private HttpHeaders httpHeaders;

    private Log log = LogFactory.getLog(getClass().getName());

    @Override
    public Response toResponse(Exception e) {

        Response.ResponseBuilder builder;
        Response.Status status;
        String message = null;

        if (e instanceof StuffNotFoundException) {
            status =Response.Status.NOT_FOUND;
        } else if (e instanceof ResourceNotFoundException) {
            status = Response.Status.NOT_FOUND;
        } else if (e instanceof ResourceGroupNotFoundException) {
            status = Response.Status.NOT_FOUND;
        } else if (e instanceof ResourceTypeNotFoundException) {
            status = Response.Status.NOT_FOUND;
        } else if (e instanceof ParameterMissingException) {
            status = Response.Status.NOT_ACCEPTABLE;
        } else if (e instanceof BadArgumentException) {
            status = Response.Status.NOT_ACCEPTABLE;
        } else if (e instanceof PermissionException) {
            status = Response.Status.FORBIDDEN;
        } else if (e instanceof EJBException && e.getCause()!=null) {
            Throwable cause = e.getCause();
            if (cause instanceof IllegalArgumentException) {
                status = Response.Status.NOT_ACCEPTABLE;
            } else if (cause instanceof UndeclaredThrowableException ) {
                if (cause.getCause() != null && cause.getCause() instanceof IllegalAccessException) {
                    status = Response.Status.FORBIDDEN;
                    message = "User was authorized, but has no rights for the operation."+
                        " If this is an LDAP user, the user needs to log in to the UI and complete registration.";
                } else {
                    status = Response.Status.SERVICE_UNAVAILABLE;
                }
            } else {
                status = Response.Status.SERVICE_UNAVAILABLE;
            }
        } else {
            status = Response.Status.SERVICE_UNAVAILABLE;
        }

        builder = Response.status(status);
        if (message == null) {
            message = e.getMessage();
        }
        wrapMessage(builder, message);
        return builder.build();
    }

    /**
     * Wrap the passed message according to the mediaType from the HttpHeader. If the
     * type can not be determined, we use plain text
     * @param builder ResponseBuilder to add the message to
     * @param message The message to wrap
     */
    private void wrapMessage(Response.ResponseBuilder builder, String message) {

        MediaType mediaType;
        try {
            mediaType = httpHeaders.getAcceptableMediaTypes().get(0);
        } catch (Exception e) {
            log.debug(e.getMessage());
            mediaType = MediaType.TEXT_PLAIN_TYPE;
        }
        if (mediaType.getType().equals("text") && mediaType.getSubtype().equals("csv")) {
            mediaType = MediaType.TEXT_PLAIN_TYPE;
        }


        if (mediaType.equals(MediaType.TEXT_PLAIN_TYPE)) {
            message = message + "\n";
            builder.entity(message);
        } else if (mediaType.equals(MediaType.TEXT_HTML_TYPE)) {
            builder.entity("<html><body><h1>Error</h1><h2>" + message + "</h2></body></html>");
        } else {
            RHQErrorWrapper error = new RHQErrorWrapper(message);
            builder.entity(error);
        }
        builder.type(mediaType);
    }
}