org.apache.log4j.PatternLayout 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;
import org.apache.log4j.helpers.PatternConverter;
import org.apache.log4j.helpers.PatternParser;
import org.apache.log4j.spi.LoggingEvent;
/**
*
*/
public class PatternLayout extends Layout {
/**
* Default pattern string for log output. Currently set to the string {@value #DEFAULT_CONVERSION_PATTERN} which
* just prints the application supplied message.
*/
public final static String DEFAULT_CONVERSION_PATTERN = "%m%n";
/**
* A conversion pattern equivalent to the TTCCCLayout. Current value is {@value #TTCC_CONVERSION_PATTERN}
*/
public final static String TTCC_CONVERSION_PATTERN = "%r [%t] %p %c %x - %m%n";
protected final int BUF_SIZE = 256;
protected final int MAX_CAPACITY = 1024;
// output buffer appended to when format() is invoked
private StringBuffer sbuf = new StringBuffer(BUF_SIZE);
private String pattern;
private PatternConverter head;
/**
* Constructs a PatternLayout using the DEFAULT_LAYOUT_PATTERN.
*
* The default pattern just produces the application supplied message.
*/
public PatternLayout() {
this(DEFAULT_CONVERSION_PATTERN);
}
/**
* Constructs a PatternLayout using the supplied conversion pattern.
*/
public PatternLayout(final String pattern) {
this.pattern = pattern;
head = createPatternParser((pattern == null) ? DEFAULT_CONVERSION_PATTERN : pattern).parse();
}
/**
* Does not do anything as options become effective
*/
public void activateOptions() {
// nothing to do.
}
/**
* Returns PatternParser used to parse the conversion string. Subclasses may override this to return a subclass of
* PatternParser which recognize custom conversion characters.
*
* @since 0.9.0
*/
protected PatternParser createPatternParser(final String pattern) {
return new PatternParser(pattern);
}
/**
* Produces a formatted string as specified by the conversion pattern.
*/
@Override
public String format(final LoggingEvent event) {
// Reset working stringbuffer
if (sbuf.capacity() > MAX_CAPACITY) {
sbuf = new StringBuffer(BUF_SIZE);
} else {
sbuf.setLength(0);
}
PatternConverter c = head;
while (c != null) {
c.format(sbuf, event);
c = c.next;
}
return sbuf.toString();
}
/**
* Returns the value of the ConversionPattern option.
*/
public String getConversionPattern() {
return pattern;
}
/**
* The PatternLayout does not handle the throwable contained within {@link LoggingEvent LoggingEvents}. Thus, it returns
* true.
*
* @since 0.8.4
*/
@Override
public boolean ignoresThrowable() {
return true;
}
/**
* Set the ConversionPattern option. This is the string which controls formatting and consists of a mix of
* literal content and conversion specifiers.
*/
public void setConversionPattern(final String conversionPattern) {
pattern = conversionPattern;
head = createPatternParser(conversionPattern).parse();
}
}