ambari-views/examples/cluster-view/src/main/java/org/apache/ambari/view/cluster/ClusterConfigServlet.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.ambari.view.cluster;

import org.apache.ambari.view.ViewContext;

import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Map;

/**
 * Simple servlet for cluster view.
 */
public class ClusterConfigServlet extends HttpServlet {

  /**
   * The view context.
   */
  private ViewContext viewContext;

  @Override
  public void init(ServletConfig config) throws ServletException {
    super.init(config);

    ServletContext context = config.getServletContext();
    viewContext = (ViewContext) context.getAttribute(ViewContext.CONTEXT_ATTRIBUTE);
  }

  @Override
  protected void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
    response.setContentType("text/html");
    response.setStatus(HttpServletResponse.SC_OK);

    PrintWriter writer = response.getWriter();

    Map<String, String> properties = viewContext.getProperties();

    writer.println("<h1>Cluster Configurations</h1>");
    writer.println("</br>hdfs_user       = " + properties.get("hdfs_user"));
    writer.println("</br>proxyuser_group = " + properties.get("proxyuser_group"));
  }
}