org.apache.drill.common.logical.JSONOptions.java Source code

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Here is the source code for org.apache.drill.common.logical.JSONOptions.java

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/*******************************************************************************
 * 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.drill.common.logical;

import java.io.IOException;

import org.apache.drill.common.exceptions.LogicalPlanParsingException;
import org.apache.drill.common.logical.JSONOptions.De;
import org.apache.drill.common.logical.JSONOptions.Se;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.fasterxml.jackson.core.JsonGenerationException;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonLocation;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonParser.Feature;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.TreeNode;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.databind.SerializerProvider;
import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
import com.fasterxml.jackson.databind.annotation.JsonSerialize;
import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
import com.fasterxml.jackson.databind.ser.std.StdSerializer;

@JsonSerialize(using = Se.class)
@JsonDeserialize(using = De.class)
public class JSONOptions {
    private static volatile ObjectMapper MAPPER;

    final static Logger logger = LoggerFactory.getLogger(JSONOptions.class);

    private JsonNode root;
    private JsonLocation location;

    public JSONOptions(JsonNode n, JsonLocation location) { //wcl
        //private JSONOptions(JsonNode n, JsonLocation location){
        this.root = n;
        this.location = location;
    }

    public <T> T getWith(Class<T> c) {
        try {
            //logger.debug("Read tree {}", root);
            return getMapper().treeToValue(root, c);
        } catch (JsonProcessingException e) {
            throw new LogicalPlanParsingException(String.format(
                    "Failure while trying to convert late bound json options to type of %s. Reference was originally located at line %d, column %d.",
                    c.getCanonicalName(), location.getLineNr(), location.getColumnNr()), e);
        }
    }

    public JsonNode path(String name) {
        return root.path(name);
    }

    private static synchronized ObjectMapper getMapper() {
        if (MAPPER == null) {
            ObjectMapper mapper = new ObjectMapper();
            mapper.enable(SerializationFeature.INDENT_OUTPUT);
            mapper.configure(Feature.ALLOW_UNQUOTED_FIELD_NAMES, true);
            mapper.configure(Feature.ALLOW_COMMENTS, true);
            MAPPER = mapper;
        }
        return MAPPER;
    }

    public static class De extends StdDeserializer<JSONOptions> {

        public De() {
            super(JSONOptions.class);
            logger.debug("Creating Deserializer.");
        }

        @Override
        public JSONOptions deserialize(JsonParser jp, DeserializationContext ctxt)
                throws IOException, JsonProcessingException {
            JsonLocation l = jp.getTokenLocation();
            //logger.debug("Reading tree.");
            TreeNode n = jp.readValueAsTree();
            if (n instanceof JsonNode) {
                return new JSONOptions((JsonNode) n, l);
            } else {
                ctxt.mappingException("Failure reading json options as JSON value.");
                return null;
            }
        }

    }

    public static class Se extends StdSerializer<JSONOptions> {

        public Se() {
            super(JSONOptions.class);
        }

        @Override
        public void serialize(JSONOptions value, JsonGenerator jgen, SerializerProvider provider)
                throws IOException, JsonGenerationException {
            jgen.writeTree(value.root);
        }

    }
}