org.apache.hadoop.gateway.util.JsonUtils.java Source code

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Here is the source code for org.apache.hadoop.gateway.util.JsonUtils.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.hadoop.gateway.util;

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

import org.apache.hadoop.gateway.i18n.GatewayUtilCommonMessages;
import org.apache.hadoop.gateway.i18n.messages.MessagesFactory;

import com.fasterxml.jackson.core.JsonFactory;
import com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.ObjectMapper;

public class JsonUtils {

    private static final GatewayUtilCommonMessages LOG = MessagesFactory.get(GatewayUtilCommonMessages.class);

    public static String renderAsJsonString(Map<String, Object> map) {
        String json = null;
        ObjectMapper mapper = new ObjectMapper();

        try {
            // write JSON to a file
            json = mapper.writeValueAsString((Object) map);

        } catch (JsonProcessingException e) {
            LOG.failedToSerializeMapToJSON(map, e);
        }
        return json;
    }

    public static Map<String, String> getMapFromJsonString(String json) {
        Map<String, String> map = null;
        JsonFactory factory = new JsonFactory();
        ObjectMapper mapper = new ObjectMapper(factory);
        TypeReference<HashMap<String, String>> typeRef = new TypeReference<HashMap<String, String>>() {
        };
        try {
            map = mapper.readValue(json, typeRef);
        } catch (JsonParseException e) {
            LOG.failedToGetMapFromJsonString(json, e);
        } catch (JsonMappingException e) {
            LOG.failedToGetMapFromJsonString(json, e);
        } catch (IOException e) {
            LOG.failedToGetMapFromJsonString(json, e);
        }
        return map;
    }
}