src/main/java/io/mifos/core/lang/config/ServiceExceptionFilter.java

/*
 * Copyright 2017 The Mifos Initiative
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package io.mifos.core.lang.config;

import io.mifos.core.lang.ServiceError;
import io.mifos.core.lang.ServiceException;
import org.springframework.web.filter.OncePerRequestFilter;
import org.springframework.web.util.NestedServletException;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

final class ServiceExceptionFilter extends OncePerRequestFilter {

  ServiceExceptionFilter() {
    super();
  }

  @Override
  protected void doFilterInternal(final HttpServletRequest request,
                                  final HttpServletResponse response,
                                  final FilterChain filterChain)
      throws ServletException, IOException {
    try {
      filterChain.doFilter(request, response);
    } catch (final NestedServletException ex) {
      if (ServiceException.class.isAssignableFrom(ex.getCause().getClass())) {
        @SuppressWarnings("ThrowableResultOfMethodCallIgnored") final ServiceException serviceException = ServiceException.class.cast(ex.getCause());
        final ServiceError serviceError = serviceException.serviceError();
        logger.info("Responding with a service error " + serviceError);
        response.sendError(serviceError.getCode(), serviceError.getMessage());
      } else {
        throw ex;
      }
    }
  }
}