lens-server/src/main/java/org/apache/lens/server/ServerModeFilter.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.NotAllowedException;
import javax.ws.rs.container.ContainerRequestContext;
import javax.ws.rs.container.ContainerRequestFilter;

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

  /*
   * (non-Javadoc)
   *
   * @see javax.ws.rs.container.ContainerRequestFilter#filter(javax.ws.rs.container.ContainerRequestContext)
   */
  @Override
  public void filter(ContainerRequestContext requestContext) throws IOException {
    switch (LensServices.get().getServiceMode()) {
    case READ_ONLY:
      // Allows all requests on session and only GET everywhere
      if (!requestContext.getUriInfo().getPath().startsWith("session")) {
        if (!requestContext.getMethod().equals("GET")) {
          throw new NotAllowedException("Server is in readonly mode. Request on path:"
            + requestContext.getUriInfo().getPath(), "GET", (String[]) null);
        }
      }
      break;
    case METASTORE_READONLY:
      // Allows GET on metastore and all other requests
      if (requestContext.getUriInfo().getPath().startsWith("metastore")) {
        if (!requestContext.getMethod().equals("GET")) {
          throw new NotAllowedException("Metastore is in readonly mode. Request on path:"
            + requestContext.getUriInfo().getPath(), "GET", (String[]) null);
        }
      }
      break;
    case METASTORE_NODROP:
      // Does not allows DROP on metastore, all other request are allowed
      if (requestContext.getUriInfo().getPath().startsWith("metastore")) {
        if (requestContext.getMethod().equals("DELETE")) {
          throw new NotAllowedException("Metastore is in nodrop mode. Request on path:"
            + requestContext.getUriInfo().getPath(), "GET", new String[]{"PUT", "POST"});
        }
      }
      break;

    case OPEN:
      // nothing to do
    }
  }
}