de.beyondjava.angularFaces.components.puiSync.JSONUtilities.java Source code

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Here is the source code for de.beyondjava.angularFaces.components.puiSync.JSONUtilities.java

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/**
 *  (C) 2013-2015 Stephan Rauh http://www.beyondjava.net
 *
 * 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 de.beyondjava.angularFaces.components.puiSync;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.logging.Logger;

public class JSONUtilities {
    private static final Logger LOGGER = Logger
            .getLogger("de.beyondjava.angularFaces.components.puiSync.JSONUtilities");

    private static Object gson;
    private static Object jackson;

    static {
        try {
            Class<?> jacksonClass = Class.forName("com.fasterxml.jackson.databind.ObjectMapper");
            jackson = jacksonClass.newInstance();
        } catch (Exception e) {
            try {
                Class<?> jacksonClass = Class.forName("org.codehaus.jackson.map.ObjectMapper");
                jackson = jacksonClass.newInstance();
            } catch (Exception e2) {
                jackson = null;
            }
        }
        try {
            Class<?> gsonClass = Class.forName("com.google.gson.Gson");
            gson = gsonClass.newInstance();
        } catch (Exception e) {
            gson = null;
        }
        if (jackson == null && gson == null) {
            LOGGER.severe(
                    "Please specify a JSON serializer! Current Gson and Jackson 1 and Jackson 2 are supported.");
            LOGGER.severe("To add Jackson, simply add these lines to your pom.xml:");
            LOGGER.severe("<dependency>");
            LOGGER.severe("  <groupId>com.fasterxml.jackson.jaxrs</groupId>");
            LOGGER.severe("  <artifactId>jackson-jaxrs-json-provider</artifactId>");
            LOGGER.severe("  <version>2.4.2</version>");
            LOGGER.severe("</dependency>");

        }

    }

    @SuppressWarnings("unchecked")
    public static Object readObjectFromJSONString(String json, Class beanType) {
        if (null != jackson) {
            try {
                Method method = jackson.getClass().getMethod("readValue", String.class, Class.class);
                if (null != method) {
                    return method.invoke(jackson, json, beanType);
                }
            } catch (InvocationTargetException e) {
                Throwable rootException = e.getTargetException();
                System.out.println("Jackson couldn't read the value: " + rootException);

            } catch (ReflectiveOperationException e) {
                System.out.println("Jackson couldn't read the value: " + e);
            }
        }
        if (null != gson) {
            try {
                Method method = gson.getClass().getMethod("fromJson", String.class, Class.class);
                if (null != method) {
                    return method.invoke(gson, json, beanType);
                }
            } catch (ReflectiveOperationException e) {
            }
        }
        return null;
    }

    public static String writeObjectToJSONString(Object bean) {
        if (null != jackson) {
            try {
                Method method = jackson.getClass().getMethod("writeValueAsString", Object.class);
                if (null != method) {
                    return (String) method.invoke(jackson, bean);
                }
            } catch (ReflectiveOperationException e) {
            }

        }
        if (null != gson) {
            try {
                Method method = gson.getClass().getMethod("toJson", Object.class);
                if (null != method) {
                    return (String) method.invoke(gson, bean);
                }
            } catch (ReflectiveOperationException e) {
            }
        }
        return null;
    }
}

// Support for Jackson:
// //1. Convert Java object to JSON format
// org.codehaus.jackson.map.ObjectMapper mapper = new org.codehaus.jackson.map.ObjectMapper();
// mapper.writeValue(new File("c:\\user.json"), user);
// //2. Convert JSON to Java object
// org.codehaus.jackson.map.ObjectMapper mapper = new org.codehaus.jackson.map.ObjectMapper();
// User user = mapper.readValue(new File("c:\\user.json"), User.class);