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.jackson;
018
019import java.io.IOException;
020import java.util.Map;
021
022import org.apache.logging.log4j.util.ReadOnlyStringMap;
023import org.apache.logging.log4j.util.TriConsumer;
024
025import com.fasterxml.jackson.core.JsonGenerationException;
026import com.fasterxml.jackson.core.JsonGenerator;
027import com.fasterxml.jackson.databind.SerializerProvider;
028import com.fasterxml.jackson.databind.ser.std.StdSerializer;
029
030/**
031 * <p>
032 * <em>Consider this class private.</em>
033 * </p>
034 */
035public class ContextDataSerializer extends StdSerializer<ReadOnlyStringMap> {
036
037    private static final long serialVersionUID = 1L;
038
039    protected ContextDataSerializer() {
040        super(Map.class, false);
041    }
042
043    @Override
044    public void serialize(final ReadOnlyStringMap contextData, final JsonGenerator jgen,
045            final SerializerProvider provider) throws IOException, JsonGenerationException {
046
047        jgen.writeStartObject();
048        contextData.forEach(WRITE_STRING_FIELD_INTO, jgen);
049        jgen.writeEndObject();
050    }
051
052    private static final TriConsumer<String, Object, JsonGenerator> WRITE_STRING_FIELD_INTO =
053            (key, value, jsonGenerator) -> {
054        try {
055            if (value == null) {
056                jsonGenerator.writeNullField(key);
057            } else {
058                jsonGenerator.writeStringField(key, String.valueOf(value));
059            }
060        } catch (final Exception ex) {
061            throw new IllegalStateException("Problem with key " + key, ex);
062        }
063    };
064}