lens-server/src/main/java/org/apache/lens/server/ConsistentStateFilter.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.lens.server;

import java.io.IOException;

import javax.ws.rs.container.ContainerRequestContext;
import javax.ws.rs.container.ContainerRequestFilter;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.Response.Status;

import org.apache.hive.service.Service.STATE;

/**
 * The Class ConsistentStateFilter.
 */
public class ConsistentStateFilter implements ContainerRequestFilter {

  /*
   * (non-Javadoc)
   *
   * @see javax.ws.rs.container.ContainerRequestFilter#filter(javax.ws.rs.container.ContainerRequestContext)
   */
  @Override
  public void filter(ContainerRequestContext requestContext) throws IOException {
    if (LensServices.get().isStopping() || LensServices.get().getServiceState().equals(STATE.NOTINITED)
      || LensServices.get().getServiceState().equals(STATE.STOPPED)) {
      requestContext.abortWith(Response.status(Status.SERVICE_UNAVAILABLE)
        .entity("Server is going down or is getting initialized").build());
    }
  }
}