001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache license, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the license for the specific language governing permissions and 015 * limitations under the license. 016 */ 017 018 package org.apache.logging.log4j.core.pattern; 019 020 /** 021 * Modifies the output of a pattern converter for a specified minimum and maximum width and alignment. 022 */ 023 public final class FormattingInfo { 024 /** 025 * Array of spaces. 026 */ 027 private static final char[] SPACES = new char[] { ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ' }; 028 029 /** 030 * Default instance. 031 */ 032 private static final FormattingInfo DEFAULT = new FormattingInfo(false, 0, Integer.MAX_VALUE); 033 034 /** 035 * Minimum length. 036 */ 037 private final int minLength; 038 039 /** 040 * Maximum length. 041 */ 042 private final int maxLength; 043 044 /** 045 * Alignment. 046 */ 047 private final boolean leftAlign; 048 049 /** 050 * Creates new instance. 051 * 052 * @param leftAlign 053 * left align if true. 054 * @param minLength 055 * minimum length. 056 * @param maxLength 057 * maximum length. 058 */ 059 public FormattingInfo(final boolean leftAlign, final int minLength, final int maxLength) { 060 this.leftAlign = leftAlign; 061 this.minLength = minLength; 062 this.maxLength = maxLength; 063 } 064 065 /** 066 * Gets default instance. 067 * 068 * @return default instance. 069 */ 070 public static FormattingInfo getDefault() { 071 return DEFAULT; 072 } 073 074 /** 075 * Determine if left aligned. 076 * 077 * @return true if left aligned. 078 */ 079 public boolean isLeftAligned() { 080 return leftAlign; 081 } 082 083 /** 084 * Get minimum length. 085 * 086 * @return minimum length. 087 */ 088 public int getMinLength() { 089 return minLength; 090 } 091 092 /** 093 * Get maximum length. 094 * 095 * @return maximum length. 096 */ 097 public int getMaxLength() { 098 return maxLength; 099 } 100 101 /** 102 * Adjust the content of the buffer based on the specified lengths and alignment. 103 * 104 * @param fieldStart 105 * start of field in buffer. 106 * @param buffer 107 * buffer to be modified. 108 */ 109 public void format(final int fieldStart, final StringBuilder buffer) { 110 final int rawLength = buffer.length() - fieldStart; 111 112 if (rawLength > maxLength) { 113 buffer.delete(fieldStart, buffer.length() - maxLength); 114 } else if (rawLength < minLength) { 115 if (leftAlign) { 116 final int fieldEnd = buffer.length(); 117 buffer.setLength(fieldStart + minLength); 118 119 for (int i = fieldEnd; i < buffer.length(); i++) { 120 buffer.setCharAt(i, ' '); 121 } 122 } else { 123 int padLength = minLength - rawLength; 124 125 for (; padLength > SPACES.length; padLength -= SPACES.length) { 126 buffer.insert(fieldStart, SPACES); 127 } 128 129 buffer.insert(fieldStart, SPACES, 0, padLength); 130 } 131 } 132 } 133 134 /** 135 * Returns a String suitable for debugging. 136 * 137 * @return a String suitable for debugging. 138 */ 139 @Override 140 public String toString() { 141 StringBuilder sb = new StringBuilder(); 142 sb.append(super.toString()); 143 sb.append("[leftAlign="); 144 sb.append(leftAlign); 145 sb.append(", maxLength="); 146 sb.append(maxLength); 147 sb.append(", minLength="); 148 sb.append(minLength); 149 sb.append(']'); 150 return sb.toString(); 151 } 152 153 }