net.logstash.logback.composite.CompositeJsonFormatter Maven / Gradle / Ivy
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/**
* 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 net.logstash.logback.composite;
import java.io.IOException;
import java.io.OutputStream;
import java.io.Writer;
import java.lang.ref.SoftReference;
import net.logstash.logback.decorate.JsonFactoryDecorator;
import net.logstash.logback.decorate.JsonGeneratorDecorator;
import net.logstash.logback.decorate.NullJsonFactoryDecorator;
import net.logstash.logback.decorate.NullJsonGeneratorDecorator;
import ch.qos.logback.access.spi.IAccessEvent;
import ch.qos.logback.classic.spi.ILoggingEvent;
import ch.qos.logback.core.spi.ContextAware;
import ch.qos.logback.core.spi.ContextAwareBase;
import ch.qos.logback.core.spi.DeferredProcessingAware;
import ch.qos.logback.core.spi.LifeCycle;
import com.fasterxml.jackson.core.JsonEncoding;
import com.fasterxml.jackson.core.JsonFactory;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.io.SegmentedStringWriter;
import com.fasterxml.jackson.core.util.BufferRecycler;
import com.fasterxml.jackson.core.util.ByteArrayBuilder;
import com.fasterxml.jackson.databind.MappingJsonFactory;
/**
* Formats logstash Events as JSON using {@link JsonProvider}s.
*
*
* The {@link CompositeJsonFormatter} starts the JSON object ('{'),
* then delegates writing the contents of the object to the {@link JsonProvider}s,
* and then ends the JSON object ('}').
*
* @param type of event ({@link ILoggingEvent} or {@link IAccessEvent}).
*/
public abstract class CompositeJsonFormatter
extends ContextAwareBase implements LifeCycle {
/**
* This ThreadLocal contains a {@link java.lang.ref.SoftReference}
* to a {@link BufferRecycler} used to provide a low-cost
* buffer recycling between writer instances.
*/
private final ThreadLocal> recycler = new ThreadLocal>() {
protected SoftReference initialValue() {
final BufferRecycler bufferRecycler = new BufferRecycler();
return new SoftReference(bufferRecycler);
}
};
/**
* Used to create the necessary {@link JsonGenerator}s for generating JSON.
*/
private MappingJsonFactory jsonFactory = (MappingJsonFactory) new MappingJsonFactory()
.enable(JsonGenerator.Feature.ESCAPE_NON_ASCII)
/*
* When generators are flushed, don't flush the underlying outputStream.
*
* This allows some streaming optimizations when using an encoder.
*
* The encoder generally determines when the stream should be flushed
* by an 'immediateFlush' property.
*
* The 'immediateFlush' property of the encoder can be set to false
* when the appender performs the flushes at appropriate times
* (such as the end of a batch in the AbstractLogstashTcpSocketAppender).
*/
.disable(JsonGenerator.Feature.FLUSH_PASSED_TO_STREAM);
/**
* Decorates the {@link #jsonFactory}.
* Allows customization of the {@link #jsonFactory}.
*/
private JsonFactoryDecorator jsonFactoryDecorator = new NullJsonFactoryDecorator();
/**
* Decorates the generators generated by the {@link #jsonFactory}.
* Allows customization of the generators.
*/
private JsonGeneratorDecorator jsonGeneratorDecorator = new NullJsonGeneratorDecorator();
/**
* The providers that are used to populate the output JSON object.
*/
private JsonProviders jsonProviders = new JsonProviders();
private JsonEncoding encoding = JsonEncoding.UTF8;
private volatile boolean started;
public CompositeJsonFormatter(ContextAware declaredOrigin) {
super(declaredOrigin);
}
@Override
public void start() {
if (jsonProviders.getProviders().isEmpty()) {
addError("No providers configured");
}
jsonFactory = this.jsonFactoryDecorator.decorate(this.jsonFactory);
jsonProviders.setJsonFactory(jsonFactory);
jsonProviders.setContext(context);
jsonProviders.start();
started = true;
}
@Override
public void stop() {
jsonProviders.stop();
started = false;
}
@Override
public boolean isStarted() {
return started;
}
public byte[] writeEventAsBytes(Event event) throws IOException {
ByteArrayBuilder outputStream = new ByteArrayBuilder(getBufferRecycler());
try {
writeEventToOutputStream(event, outputStream);
outputStream.flush();
return outputStream.toByteArray();
} finally {
outputStream.release();
}
}
public void writeEventToOutputStream(Event event, OutputStream outputStream) throws IOException {
JsonGenerator generator = createGenerator(outputStream);
writeEventToGenerator(generator, event);
/*
* Do not flush the outputStream.
*
* Allow something higher in the stack (e.g. the encoder/appender)
* to determine appropriate times to flush.
*/
}
public String writeEventAsString(Event event) throws IOException {
SegmentedStringWriter writer = new SegmentedStringWriter(getBufferRecycler());
JsonGenerator generator = createGenerator(writer);
writeEventToGenerator(generator, event);
writer.flush();
return writer.getAndClear();
}
protected void writeEventToGenerator(JsonGenerator generator, Event event) throws IOException {
if (!isStarted()) {
throw new IllegalStateException("Encoding attempted before starting.");
}
generator.writeStartObject();
jsonProviders.writeTo(generator, event);
generator.writeEndObject();
generator.flush();
}
protected void prepareForDeferredProcessing(Event event) {
event.prepareForDeferredProcessing();
jsonProviders.prepareForDeferredProcessing(event);
}
private JsonGenerator createGenerator(OutputStream outputStream) throws IOException {
return this.jsonGeneratorDecorator.decorate(jsonFactory.createGenerator(outputStream, encoding));
}
private JsonGenerator createGenerator(Writer writer) throws IOException {
return this.jsonGeneratorDecorator.decorate(jsonFactory.createGenerator(writer));
}
private BufferRecycler getBufferRecycler() {
SoftReference bufferRecyclerReference = recycler.get();
BufferRecycler bufferRecycler = bufferRecyclerReference.get();
if (bufferRecycler == null) {
recycler.remove();
return getBufferRecycler();
}
return bufferRecycler;
}
public JsonFactory getJsonFactory() {
return jsonFactory;
}
public JsonFactoryDecorator getJsonFactoryDecorator() {
return jsonFactoryDecorator;
}
public void setJsonFactoryDecorator(JsonFactoryDecorator jsonFactoryDecorator) {
this.jsonFactoryDecorator = jsonFactoryDecorator;
}
public JsonGeneratorDecorator getJsonGeneratorDecorator() {
return jsonGeneratorDecorator;
}
public void setJsonGeneratorDecorator(JsonGeneratorDecorator jsonGeneratorDecorator) {
this.jsonGeneratorDecorator = jsonGeneratorDecorator;
}
public JsonProviders getProviders() {
return jsonProviders;
}
public String getEncoding() {
return encoding.getJavaName();
}
public void setEncoding(String encodingName) {
for (JsonEncoding encoding: JsonEncoding.values()) {
if (encoding.getJavaName().equals(encodingName) || encoding.name().equals(encodingName)) {
this.encoding = encoding;
return;
}
}
throw new IllegalArgumentException("Unknown encoding " + encodingName);
}
public void setProviders(JsonProviders jsonProviders) {
this.jsonProviders = jsonProviders;
}
}