log4j-core/src/main/java/org/apache/logging/log4j/core/async/AsyncLoggerConfigDefaultExceptionHandler.java

/*
 * 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.async;

import com.lmax.disruptor.ExceptionHandler;

/**
 * Default disruptor exception handler for errors that occur in the AsyncLogger background thread.
 */
public class AsyncLoggerConfigDefaultExceptionHandler
        implements ExceptionHandler<AsyncLoggerConfigDisruptor.Log4jEventWrapper> {

    @Override
    public void handleEventException(final Throwable throwable, final long sequence,
            final AsyncLoggerConfigDisruptor.Log4jEventWrapper event) {
        final StringBuilder sb = new StringBuilder(512);
        sb.append("AsyncLogger error handling event seq=").append(sequence).append(", value='");
        try {
            sb.append(event);
        } catch (final Exception ignored) {
            sb.append("[ERROR calling ").append(event.getClass()).append(".toString(): ");
            sb.append(ignored).append("]");
        }
        sb.append("':");
        System.err.println(sb);
        throwable.printStackTrace();
    }

    @Override
    public void handleOnStartException(final Throwable throwable) {
        System.err.println("AsyncLogger error starting:");
        throwable.printStackTrace();
    }

    @Override
    public void handleOnShutdownException(final Throwable throwable) {
        System.err.println("AsyncLogger error shutting down:");
        throwable.printStackTrace();
    }
}