org.apache.log4j.pattern.FormattingInfo Maven / Gradle / Ivy
/*
* 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.log4j.pattern;
/**
* Modifies the output of a pattern converter for a specified minimum and
* maximum width and alignment.
*
*
* @author Jim Cakalic
* @author Ceki Gülcü
* @author Curt Arnold
*
*/
public final class FormattingInfo {
/**
* Array of spaces.
*/
private static final char[] SPACES = new char[] { ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ' };
/**
* Default instance.
*/
private static final FormattingInfo DEFAULT = new FormattingInfo(false, 0, Integer.MAX_VALUE);
/**
* Minimum length.
*/
private final int minLength;
/**
* Maximum length.
*/
private final int maxLength;
/**
* Alignment.
*/
private final boolean leftAlign;
/**
* Creates new instance.
*
* @param leftAlign left align if true.
* @param minLength minimum length.
* @param maxLength maximum length.
*/
public FormattingInfo(final boolean leftAlign, final int minLength, final int maxLength) {
this.leftAlign = leftAlign;
this.minLength = minLength;
this.maxLength = maxLength;
}
/**
* Gets default instance.
*
* @return default instance.
*/
public static FormattingInfo getDefault() {
return DEFAULT;
}
/**
* Determine if left aligned.
*
* @return true if left aligned.
*/
public boolean isLeftAligned() {
return leftAlign;
}
/**
* Get minimum length.
*
* @return minimum length.
*/
public int getMinLength() {
return minLength;
}
/**
* Get maximum length.
*
* @return maximum length.
*/
public int getMaxLength() {
return maxLength;
}
/**
* Adjust the content of the buffer based on the specified lengths and
* alignment.
*
* @param fieldStart start of field in buffer.
* @param buffer buffer to be modified.
*/
public void format(final int fieldStart, final StringBuffer buffer) {
final int rawLength = buffer.length() - fieldStart;
if (rawLength > maxLength) {
buffer.delete(fieldStart, buffer.length() - maxLength);
} else if (rawLength < minLength) {
if (leftAlign) {
final int fieldEnd = buffer.length();
buffer.setLength(fieldStart + minLength);
for (int i = fieldEnd; i < buffer.length(); i++) {
buffer.setCharAt(i, ' ');
}
} else {
int padLength = minLength - rawLength;
for (; padLength > 8; padLength -= 8) {
buffer.insert(fieldStart, SPACES);
}
buffer.insert(fieldStart, SPACES, 0, padLength);
}
}
}
}