001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.hbtop.screen.top;
019
020import java.util.Objects;
021import org.apache.hadoop.hbase.hbtop.field.Field;
022import org.apache.yetus.audience.InterfaceAudience;
023
024
025/**
026 * Represents headers for the metrics in the top screen.
027 */
028@InterfaceAudience.Private
029public class Header {
030  private final Field field;
031  private final int length;
032
033  public Header(Field field, int length) {
034    this.field = Objects.requireNonNull(field);
035    this.length = length;
036  }
037
038  public String format() {
039    return "%" + (field.isLeftJustify() ? "-" : "")  + length + "s";
040  }
041
042  public Field getField() {
043    return field;
044  }
045
046  public int getLength() {
047    return length;
048  }
049}