com.hurence.logisland.utils.JsonUtil.java Source code

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Here is the source code for com.hurence.logisland.utils.JsonUtil.java

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/*
 * Copyright 2016 Hurence
 *
 * Licensed 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 com.hurence.logisland.utils;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.type.TypeReference;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * Some JSON helper utilities.
 *
 * @author Thomas Risberg
 *
 */
public class JsonUtil {

    protected static final Log logger = LogFactory.getLog(JsonUtil.class);

    private final static ObjectMapper mapper = new ObjectMapper();

    public static Map<String, Object> convertJsonToMap(String json) {
        Map<String, Object> retMap = new HashMap<>();
        if (json != null) {
            try {
                retMap = mapper.readValue(json, new TypeReference<Map<String, Object>>() {
                });
            } catch (IOException e) {
                logger.warn("Error while reading Java Map from JSON response: " + json, e);
            }
        }
        return retMap;
    }

    public static List<String> convertJsonToList(String json) {
        List<String> retList = new ArrayList<>();
        if (json != null) {
            try {
                retList = mapper.readValue(json, new TypeReference<List<String>>() {
                });
            } catch (IOException e) {
                logger.warn("Error while reading Java List from JSON response: " + json, e);
            }
        }
        return retList;
    }

    public static String convertToJson(Object value) {
        if (mapper.canSerialize(value.getClass())) {
            try {
                return mapper.writeValueAsString(value);
            } catch (IOException e) {
                logger.warn("Error while serializing " + value + " to JSON", e);
                return null;
            }
        } else {
            throw new IllegalArgumentException(
                    "Value of type " + value.getClass().getName() + " can not be serialized to JSON.");
        }
    }

}