log4j-layout-jackson/src/main/java/org/apache/logging/log4j/jackson/ContextDataDeserializer.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.jackson;

import java.io.IOException;
import java.util.Map;

import org.apache.logging.log4j.core.impl.ContextDataFactory;
import org.apache.logging.log4j.util.StringMap;

import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.JsonToken;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.deser.std.StdDeserializer;

/**
 * <p>
 * <em>Consider this class private.</em>
 * </p>
 */
public class ContextDataDeserializer extends StdDeserializer<StringMap> {

    private static final long serialVersionUID = 1L;

    ContextDataDeserializer() {
        super(Map.class);
    }

    @Override
    public StringMap deserialize(final JsonParser jp, final DeserializationContext ctxt) throws IOException,
            JsonProcessingException {

        // Sanity check: verify that we got "Json Object":
//        JsonToken tok = jp.nextToken();
//        if (tok != JsonToken.START_OBJECT) {
//            throw new IOException("Expected data to start with an Object");
//        }
        final StringMap contextData = ContextDataFactory.createContextData();
        // Iterate over object fields:
        while (jp.nextToken() != JsonToken.END_OBJECT) {
            final String fieldName = jp.getCurrentName();

            // move to value
            jp.nextToken();
            contextData.putValue(fieldName, jp.getText());
        }
        return contextData;
    }
}