/*
* 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.jpa.converter;
import java.io.IOException;
import java.util.List;
import javax.persistence.AttributeConverter;
import javax.persistence.Converter;
import javax.persistence.PersistenceException;
import org.apache.logging.log4j.ThreadContext;
import org.apache.logging.log4j.core.helpers.Strings;
import org.apache.logging.log4j.spi.DefaultThreadContextStack;
import com.fasterxml.jackson.core.type.TypeReference;
/**
* A JPA 2.1 attribute converter for
* {@link org.apache.logging.log4j.ThreadContext.ContextStack ThreadContext.ContextStack}s in
* {@link org.apache.logging.log4j.core.LogEvent}s. This converter is capable of converting both to and from
* {@link String}s.
*
* In addition to other optional dependencies required by the JPA appender, this converter requires the Jackson Data
* Processor.
*/
@Converter(autoApply = false)
public class ContextStackJsonAttributeConverter implements AttributeConverter<ThreadContext.ContextStack, String> {
@Override
public String convertToDatabaseColumn(final ThreadContext.ContextStack contextStack) {
if (contextStack == null) {
return null;
}
try {
return ContextMapJsonAttributeConverter.OBJECT_MAPPER.writeValueAsString(contextStack.asList());
} catch (final IOException e) {
throw new PersistenceException("Failed to convert stack list to JSON string.", e);
}
}
@Override
public ThreadContext.ContextStack convertToEntityAttribute(final String s) {
if (Strings.isEmpty(s)) {
return null;
}
List<String> list;
try {
list = ContextMapJsonAttributeConverter.OBJECT_MAPPER.readValue(s, new TypeReference<List<String>>() { });
} catch (final IOException e) {
throw new PersistenceException("Failed to convert JSON string to list for stack.", e);
}
final DefaultThreadContextStack result = new DefaultThreadContextStack(true);
result.addAll(list);
return result;
}
}