001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache license, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the license for the specific language governing permissions and
015 * limitations under the license.
016 */
017package org.apache.logging.log4j.core.appender.db.jpa.converter;
018
019import java.util.Map;
020
021import javax.persistence.AttributeConverter;
022import javax.persistence.Converter;
023
024/**
025 * A JPA 2.1 attribute converter for {@link Map Map<String, String>}s in
026 * {@link org.apache.logging.log4j.core.LogEvent}s. This converter is only capable of converting to {@link String}s. The
027 * {@link #convertToEntityAttribute(String)} method throws an {@link UnsupportedOperationException}. If you need to
028 * support converting to an entity attribute, you should use the {@link ContextMapJsonAttributeConverter} for conversion
029 * both ways.
030 */
031@Converter(autoApply = false)
032public class ContextMapAttributeConverter implements AttributeConverter<Map<String, String>, String> {
033    @Override
034    public String convertToDatabaseColumn(final Map<String, String> contextMap) {
035        if (contextMap == null) {
036            return null;
037        }
038
039        return contextMap.toString();
040    }
041
042    @Override
043    public Map<String, String> convertToEntityAttribute(final String s) {
044        throw new UnsupportedOperationException("Log events can only be persisted, not extracted.");
045    }
046}