org.apache.juli.logging.net.logstash.logback.marker.LogstashMarker Maven / Gradle / Ivy
/*
* Copyright 2013-2023 the original author or authors.
*
* Licensed 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.juli.logging.net.logstash.logback.marker;
import java.io.IOException;
import org.apache.juli.logging.com.fasterxml.jackson.core.JsonGenerator;
import org.apache.juli.logging.org.slf4j.Marker;
/**
* A {@link Marker} that is known and understood by the logstash logback encoder.
*
* In particular these markers are used to write data into the logstash json event via {@link #writeTo(JsonGenerator)}.
*/
@SuppressWarnings("serial")
public abstract class LogstashMarker extends LogstashBasicMarker implements Iterable {
public static final String MARKER_NAME_PREFIX = "LS_";
public LogstashMarker(String name) {
super(name);
}
/**
* Adds the given marker as a reference, and returns this marker.
*
* This can be used to chain markers together fluently on a log line. For example:
*
*
* {@code
* import static org.apache.juli.logging.net.logstash.logback.marker.Markers.*
*
* logger.info(append("name1", "value1).and(append("name2", "value2")), "log message");
* }
*
*
* @param subtype of LogstashMarker
* @param reference The marker to add
* @return A marker with this marker and the given marker
*/
@SuppressWarnings("unchecked")
public T and(Marker reference) {
add(reference);
return (T) this;
}
/**
* @param subtype of LogstashMarker
* @param reference The marker to add
* @deprecated Use {@link #and(Marker)} instead
* @see #and(Marker)
* @return A marker with this marker and the given marker
*/
@Deprecated
public T with(Marker reference) {
return and(reference);
}
/**
* Writes the data associated with this marker to the given {@link JsonGenerator}.
*
* @param generator the generator to which to write the output of this marker.
* @throws IOException if there was an error writing to the generator
*/
public abstract void writeTo(JsonGenerator generator) throws IOException;
@Override
public void add(Marker reference) {
if (reference instanceof EmptyLogstashMarker) {
for (Marker m : (EmptyLogstashMarker) reference) {
add(m);
}
} else {
super.add(reference);
}
}
/**
* Returns a String in the form of
*
* self, reference1, reference2, ...
*
*
* Where self
is the value returned by {@link #toStringSelf()},
* and reference*
are the toString()
values of any references.
*
* It is recommended that subclasses only override {@link #toStringSelf()},
* so that references are automatically included in the value returned from {@link #toString()}.
*
* @return a string representation of the object, which includes references
*/
@Override
public String toString() {
String self = toStringSelf();
if (!hasReferences()) {
return self;
}
StringBuilder sb = new StringBuilder(self);
boolean appendSeparator = !self.isEmpty();
for (Marker marker : this) {
if (appendSeparator) {
sb.append(", ");
}
String referenceToString = marker.toString();
if (!referenceToString.isEmpty()) {
sb.append(referenceToString);
appendSeparator = true;
}
}
return sb.toString();
}
/**
* Returns a string representation of this object, without including any references.
*
* Subclasses should override {@link #toStringSelf()} instead of {@link #toString()},
* since {@link #toString()} will automatically include the {@link #toStringSelf()} and references.
*
* @return a string representation of this object, without including any references.
*/
protected String toStringSelf() {
return getName();
}
}