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/**
 * 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.hadoop.util;

import java.io.*;
import java.util.Calendar;

import javax.servlet.*;

public class ServletUtil {
  /**
   * Initial HTML header
   */
  public static PrintWriter initHTML(ServletResponse response, String title
      ) throws IOException {
    response.setContentType("text/html");
    PrintWriter out = response.getWriter();
    out.println("\n"
        + "\n"
        + "" + title + "\n"
        + "\n"
        + "" + title + "\n");
    return out;
  }

  /**
   * Get a parameter from a ServletRequest.
   * Return null if the parameter contains only white spaces.
   */
  public static String getParameter(ServletRequest request, String name) {
    String s = request.getParameter(name);
    if (s == null) {
      return null;
    }
    s = s.trim();
    return s.length() == 0? null: s;
  }

  public static final String HTML_TAIL = "\n"
    + "This release is based on the Facebook Distribution of Hadoop, "
    + "powering the largest Hadoop clusters in the Universe!\n"
    + "";

  /**
   * HTML footer to be added in the jsps.
   * @return the HTML footer.
   */
  public static String htmlFooter() {
    return HTML_TAIL;
  }

  /**
   * Generate the percentage graph and returns HTML representation string
   * of the same.
   *
   * @param perc The percentage value for which graph is to be generated
   * @param width The width of the display table
   * @return HTML String representation of the percentage graph
   * @throws IOException
   */
  public static String percentageGraph(int perc, int width) throws IOException {
    assert perc >= 0; assert perc <= 100;

    StringBuilder builder = new StringBuilder();

    builder.append("");
    if(perc > 0) {
      builder.append("");
    }if(perc < 100) {
      builder.append("");
    }
    builder.append(" ");
    return builder.toString();
  }

  /**
   * Generate the percentage graph and returns HTML representation string
   * of the same.
   * @param perc The percentage value for which graph is to be generated
   * @param width The width of the display table
   * @return HTML String representation of the percentage graph
   * @throws IOException
   */
  public static String percentageGraph(float perc, int width) throws IOException {
    return percentageGraph((int)perc, width);
  }
}