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/*
* 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.logging.log4j.core.appender.db;
import java.io.Serializable;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import org.apache.logging.log4j.LoggingException;
import org.apache.logging.log4j.core.Filter;
import org.apache.logging.log4j.core.Layout;
import org.apache.logging.log4j.core.LogEvent;
import org.apache.logging.log4j.core.appender.AbstractAppender;
import org.apache.logging.log4j.core.appender.AppenderLoggingException;
import org.apache.logging.log4j.core.config.Property;
/**
* An abstract Appender for writing events to a database of some type, be it relational or NoSQL. All database appenders
* should inherit from this base appender. Three implementations are currently provided:
* {@link org.apache.logging.log4j.core.appender.db.jdbc JDBC}, {@link org.apache.logging.log4j.core.appender.db.jpa
* JPA}, and {@link org.apache.logging.log4j.core.appender.nosql NoSQL}.
*
* @param Specifies which type of {@link AbstractDatabaseManager} this Appender requires.
*/
public abstract class AbstractDatabaseAppender extends AbstractAppender {
public static class Builder> extends AbstractAppender.Builder {
// empty for now.
}
public static final int DEFAULT_RECONNECT_INTERVAL_MILLIS = 5000;
private final ReadWriteLock lock = new ReentrantReadWriteLock();
private final Lock readLock = lock.readLock();
private final Lock writeLock = lock.writeLock();
private T manager;
/**
* Instantiates the base appender.
*
* @param name The appender name.
* @param filter The filter, if any, to use.
* @param ignoreExceptions If {@code true} exceptions encountered when appending events are logged; otherwise
* they are propagated to the caller.
* @param manager The matching {@link AbstractDatabaseManager} implementation.
* @deprecated Use {@link #AbstractDatabaseAppender(String, Filter, Layout, boolean, Property[], AbstractDatabaseManager)}.
*/
@Deprecated
protected AbstractDatabaseAppender(final String name, final Filter filter, final boolean ignoreExceptions,
final T manager) {
super(name, filter, null, ignoreExceptions, Property.EMPTY_ARRAY);
this.manager = manager;
}
/**
* Instantiates the base appender.
*
* @param name The appender name.
* @param filter The filter, if any, to use.
* @param layout The layout to use to format the event.
* @param ignoreExceptions If {@code true} exceptions encountered when appending events are logged; otherwise
* they are propagated to the caller.
* @param manager The matching {@link AbstractDatabaseManager} implementation.
*/
protected AbstractDatabaseAppender(final String name, final Filter filter,
final Layout layout, final boolean ignoreExceptions,
final Property[] properties, final T manager) {
super(name, filter, layout, ignoreExceptions, properties);
this.manager = manager;
}
/**
* Instantiates the base appender.
*
* @param name The appender name.
* @param filter The filter, if any, to use.
* @param layout The layout to use to format the event.
* @param ignoreExceptions If {@code true} exceptions encountered when appending events are logged; otherwise
* they are propagated to the caller.
* @param manager The matching {@link AbstractDatabaseManager} implementation.
* @deprecated Use {@link #AbstractDatabaseAppender(String, Filter, Layout, boolean, Property[], AbstractDatabaseManager)}
*/
@Deprecated
protected AbstractDatabaseAppender(final String name, final Filter filter,
final Layout layout, final boolean ignoreExceptions, final T manager) {
super(name, filter, layout, ignoreExceptions, Property.EMPTY_ARRAY);
this.manager = manager;
}
@Override
public final void append(final LogEvent event) {
this.readLock.lock();
try {
this.getManager().write(event, toSerializable(event));
} catch (final LoggingException e) {
LOGGER.error("Unable to write to database [{}] for appender [{}].", this.getManager().getName(),
this.getName(), e);
throw e;
} catch (final Exception e) {
LOGGER.error("Unable to write to database [{}] for appender [{}].", this.getManager().getName(),
this.getName(), e);
throw new AppenderLoggingException("Unable to write to database in appender: " + e.getMessage(), e);
} finally {
this.readLock.unlock();
}
}
/**
* This always returns {@code null}, as database appenders do not use a single layout. The JPA and NoSQL appenders
* do not use a layout at all. The JDBC appender has a layout-per-column pattern.
*
* @return {@code null}.
*/
@Override
public final Layout getLayout() {
return null;
}
/**
* Returns the underlying manager in use within this appender.
*
* @return the manager.
*/
public final T getManager() {
return this.manager;
}
/**
* Replaces the underlying manager in use within this appender. This can be useful for manually changing the way log
* events are written to the database without losing buffered or in-progress events. The existing manager is
* released only after the new manager has been installed. This method is thread-safe.
*
* @param manager The new manager to install.
*/
protected final void replaceManager(final T manager) {
this.writeLock.lock();
try {
final T old = this.getManager();
if (!manager.isRunning()) {
manager.startup();
}
this.manager = manager;
old.close();
} finally {
this.writeLock.unlock();
}
}
@Override
public final void start() {
if (this.getManager() == null) {
LOGGER.error("No AbstractDatabaseManager set for the appender named [{}].", this.getName());
}
super.start();
if (this.getManager() != null) {
this.getManager().startup();
}
}
@Override
public boolean stop(final long timeout, final TimeUnit timeUnit) {
setStopping();
boolean stopped = super.stop(timeout, timeUnit, false);
if (this.getManager() != null) {
stopped &= this.getManager().stop(timeout, timeUnit);
}
setStopped();
return stopped;
}
}