JSONUtils.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.dolphinscheduler.common.utils;

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.node.ArrayNode;
import com.fasterxml.jackson.databind.node.ObjectNode;
import com.fasterxml.jackson.databind.node.TextNode;
import com.fasterxml.jackson.databind.type.CollectionType;
import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.util.*;

import static com.fasterxml.jackson.databind.DeserializationFeature.*;


/**
 * json utils
 */
public class JSONUtils {

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

    /**
     * can use static singleton, inject: just make sure to reuse!
     */
    private static final ObjectMapper objectMapper = new ObjectMapper()
            .configure(FAIL_ON_UNKNOWN_PROPERTIES, false)
            .configure(ACCEPT_EMPTY_ARRAY_AS_NULL_OBJECT, true)
            .configure(READ_UNKNOWN_ENUM_VALUES_AS_NULL, true)
            .setTimeZone(TimeZone.getDefault())
            ;

    private JSONUtils() {
    }


    public static ArrayNode createArrayNode() {
        return objectMapper.createArrayNode();
    }

    public static ObjectNode createObjectNode() {
        return objectMapper.createObjectNode();
    }

    public static JsonNode toJsonNode(Object obj) {
        return objectMapper.valueToTree(obj);
    }

    /**
     * json representation of object
     *
     * @param object object
     * @param feature feature
     * @return object to json string
     */
    public static String toJsonString(Object object, SerializationFeature feature) {
        try {
            ObjectWriter writer = objectMapper.writer(feature);
            return writer.writeValueAsString(object);
        } catch (Exception e) {
            logger.error("object to json exception!", e);
        }

        return null;
    }

    /**
     * This method deserializes the specified Json into an object of the specified class. It is not
     * suitable to use if the specified class is a generic type since it will not have the generic
     * type information because of the Type Erasure feature of Java. Therefore, this method should not
     * be used if the desired type is a generic type. Note that this method works fine if the any of
     * the fields of the specified object are generics, just the object itself should not be a
     * generic type.
     *
     * @param json  the string from which the object is to be deserialized
     * @param clazz the class of T
     * @param <T>   T
     * @return an object of type T from the string
     * classOfT
     */
    public static <T> T parseObject(String json, Class<T> clazz) {
        if (StringUtils.isEmpty(json)) {
            return null;
        }

        try {
            return objectMapper.readValue(json, clazz);
        } catch (Exception e) {
            logger.error("parse object exception!", e);
        }
        return null;
    }

    /**
     * json to list
     *
     * @param json  json string
     * @param clazz class
     * @param <T>   T
     * @return list
     */
    public static <T> List<T> toList(String json, Class<T> clazz) {
        if (StringUtils.isEmpty(json)) {
            return Collections.emptyList();
        }

        try {

            CollectionType listType = objectMapper.getTypeFactory().constructCollectionType(ArrayList.class, clazz);
            return objectMapper.readValue(json, listType);
        } catch (Exception e) {
            logger.error("parse list exception!", e);
        }

        return Collections.emptyList();
    }


    /**
     * check json object valid
     *
     * @param json json
     * @return true if valid
     */
    public static boolean checkJsonValid(String json) {

        if (StringUtils.isEmpty(json)) {
            return false;
        }

        try {
            objectMapper.readTree(json);
            return true;
        } catch (IOException e) {
            logger.error("check json object valid exception!", e);
        }

        return false;
    }


    /**
     * Method for finding a JSON Object field with specified name in this
     * node or its child nodes, and returning value it has.
     * If no matching field is found in this node or its descendants, returns null.
     *
     * @param jsonNode  json node
     * @param fieldName Name of field to look for
     * @return Value of first matching node found, if any; null if none
     */
    public static String findValue(JsonNode jsonNode, String fieldName) {
        JsonNode node = jsonNode.findValue(fieldName);

        if (node == null) {
            return null;
        }

        return node.toString();
    }


    /**
     * json to map
     * <p>
     * {@link #toMap(String, Class, Class)}
     *
     * @param json json
     * @return json to map
     */
    public static Map<String, String> toMap(String json) {
        if (StringUtils.isEmpty(json)) {
            return null;
        }

        try {
            return objectMapper.readValue(json, new TypeReference<Map<String, String>>() {});
        } catch (Exception e) {
            logger.error("json to map exception!", e);
        }

        return null;
    }

    /**
     * json to map
     *
     * @param json   json
     * @param classK classK
     * @param classV classV
     * @param <K>    K
     * @param <V>    V
     * @return to map
     */
    public static <K, V> Map<K, V> toMap(String json, Class<K> classK, Class<V> classV) {
        if (StringUtils.isEmpty(json)) {
            return null;
        }

        try {
            return objectMapper.readValue(json, new TypeReference<Map<K, V>>() {
            });
        } catch (Exception e) {
            logger.error("json to map exception!", e);
        }

        return null;
    }

    /**
     * object to json string
     *
     * @param object object
     * @return json string
     */
    public static String toJsonString(Object object) {
        try {
            return objectMapper.writeValueAsString(object);
        } catch (Exception e) {
            throw new RuntimeException("Object json deserialization exception.", e);
        }
    }

    public static ObjectNode parseObject(String text) {
        try {
            return (ObjectNode) objectMapper.readTree(text);
        } catch (Exception e) {
            throw new RuntimeException("String json deserialization exception.", e);
        }
    }

    public static ArrayNode parseArray(String text) {
        try {
            return (ArrayNode) objectMapper.readTree(text);
        } catch (Exception e) {
            throw new RuntimeException("Json deserialization exception.", e);
        }
    }


    /**
     * json serializer
     */
    public static class JsonDataSerializer extends JsonSerializer<String> {

        @Override
        public void serialize(String value, JsonGenerator gen, SerializerProvider provider) throws IOException {
            gen.writeRawValue(value);
        }

    }

    /**
     * json data deserializer
     */
    public static class JsonDataDeserializer extends JsonDeserializer<String> {

        @Override
        public String deserialize(JsonParser p, DeserializationContext ctxt) throws IOException {
            JsonNode node = p.getCodec().readTree(p);
            if (node instanceof TextNode) {
                return node.asText();
            } else {
                return node.toString();
            }
        }

    }
}