com.bitplan.json.JsonManagerImpl.java Source code

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Here is the source code for com.bitplan.json.JsonManagerImpl.java

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/**
 * Copyright (c) 2016-2017 BITPlan GmbH
 *
 * http://www.bitplan.com
 *
 * This file is part of the Opensource project at:
 * https://github.com/BITPlan/com.bitplan.simplerest
 *
 * 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.bitplan.json;

import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.io.InputStreamReader;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;

/**
 * implementation of JSonManager
 * 
 * @author wf
 *
 */
public class JsonManagerImpl<T extends JsonAble> implements JsonManager<T> {
    transient Class<T> clazz;

    /**
     * construct me for the given class
     * 
     * @param clazz
     */
    public JsonManagerImpl(Class<T> clazz) {
        super();
        this.clazz = clazz;
    }

    /**
     * get a T from the given Json File
     * 
     * @param jsonFile
     *          - the json File to get the T from
     * @return - the T
     * @throws Exception
     *           of reading from json fails
     */
    public T fromJsonFile(File jsonFile) throws Exception {
        if (jsonFile.canRead())
            return fromJsonStream(new FileInputStream(jsonFile));
        else
            return null;
    }

    /**
     * get the T from the given Json Stream
     * 
     * @param jsonStream
     * @return the Json Stream
     * @throws Exception
     */
    public T fromJsonStream(InputStream jsonStream) throws Exception {
        Gson gson = this.getGson();
        T newT = gson.fromJson(new InputStreamReader(jsonStream), clazz);
        newT.reinit();
        return newT;
    }

    @Override
    public T fromJson(String json) {
        Gson gson = this.getGson();
        T newT = gson.fromJson(json, clazz);
        newT.reinit();
        return newT;
    }

    /**
     * get the Gson
     * 
     * @return the Gson implementation
     */
    public static Gson getGsonStatic() {
        GsonBuilder gsonBuilder = new GsonBuilder();
        // new GraphAdapterBuilder().addType(Pid.class).registerOn(gsonBuilder);
        Gson gson = gsonBuilder.setPrettyPrinting().create();
        return gson;
    }

    @Override
    public Gson getGson() {
        return getGsonStatic();
    }

}