org.cloudfoundry.client.lib.util.JsonUtil Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of cloudfoundry-client-lib Show documentation
A Cloud Foundry client library for Java
The newest version!
/*
 * Copyright 2009-2012 the original author or authors.
 *
 * 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 org.cloudfoundry.client.lib.util;

import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.http.MediaType;

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

/**
 * Some JSON helper utilities used by the Cloud Foundry Java client.
 *
 * @author Thomas Risberg
 */
public class JsonUtil {

    public static final MediaType JSON_MEDIA_TYPE = new MediaType(MediaType.APPLICATION_JSON.getType(),
                                                                  MediaType.APPLICATION_JSON.getSubtype(),
                                                                  StandardCharsets.UTF_8);

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

    private static final ObjectMapper mapper = new ObjectMapper();

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

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

    public static String convertToJson(Object value) {
        return convertToJson(value, false);
    }

    public static String convertToJson(Object value, boolean shouldPrettyPrint) {
        if (shouldPrettyPrint) {
            return convertToJsonStringUsingWriter(mapper.writerWithDefaultPrettyPrinter(), value);
        }

        return convertToJsonStringUsingWriter(mapper.writer(), value);
    }

    private static String convertToJsonStringUsingWriter(ObjectWriter writer, Object value) {
        if (value == null || writer.canSerialize(value.getClass())) {
            try {
                return writer.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.");
        }
    }

    @SuppressWarnings("unchecked")
    public static List> convertToJsonList(InputStream jsonInputStream) {
        try {
            return mapper.readValue(jsonInputStream, List.class);
        } catch (JsonParseException | JsonMappingException e) {
            logger.error("Unable to parse JSON from InputStream", e);
            throw new IllegalArgumentException("Unable to parse JSON from InputStream", e);
        } catch (IOException e) {
            logger.error("Unable to process InputStream", e);
            throw new IllegalArgumentException("Unable to parse JSON from InputStream", e);
        }
    }

}