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 * Represents headers for the metrics in the top screen.
026 */
027@InterfaceAudience.Private
028public class Header {
029  private final Field field;
030  private final int length;
031
032  public Header(Field field, int length) {
033    this.field = Objects.requireNonNull(field);
034    this.length = length;
035  }
036
037  public String format() {
038    return "%" + (field.isLeftJustify() ? "-" : "") + length + "s";
039  }
040
041  public Field getField() {
042    return field;
043  }
044
045  public int getLength() {
046    return length;
047  }
048}