io.motown.chargingstationconfiguration.viewmodel.restapi.providers.GsonJsonProvider.java Source code

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Here is the source code for io.motown.chargingstationconfiguration.viewmodel.restapi.providers.GsonJsonProvider.java

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/**
 * Copyright (C) 2013 Motown.IO (info@motown.io)
 *
 * 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 io.motown.chargingstationconfiguration.viewmodel.restapi.providers;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.stream.JsonReader;
import com.google.gson.stream.JsonWriter;

import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.ext.MessageBodyReader;
import javax.ws.rs.ext.MessageBodyWriter;
import javax.ws.rs.ext.Provider;
import java.io.*;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;
import java.nio.charset.Charset;

@Provider
public final class GsonJsonProvider implements MessageBodyReader<Object>, MessageBodyWriter<Object> {
    private static final String UTF_8 = "UTF-8";

    private final Gson gson;

    public GsonJsonProvider() {
        gson = new GsonBuilder().setPrettyPrinting().disableHtmlEscaping().create();
    }

    @Override
    public boolean isReadable(Class<?> aClass, Type type, Annotation[] annotations, MediaType mediaType) {
        return true;
    }

    @Override
    public Object readFrom(Class<Object> objectClass, Type type, Annotation[] annotations, MediaType mediaType,
            MultivaluedMap<String, String> stringStringMultivaluedMap, InputStream inputStream) throws IOException {
        JsonReader reader = new JsonReader(new InputStreamReader(inputStream, Charset.forName(UTF_8)));
        Object obj = gson.fromJson(reader, type);
        reader.close();
        return obj;
    }

    @Override
    public boolean isWriteable(Class<?> aClass, Type type, Annotation[] annotations, MediaType mediaType) {
        return true;
    }

    @Override
    public long getSize(Object src, Class<?> aClass, Type type, Annotation[] annotations, MediaType mediaType) {
        return -1;
    }

    @Override
    public void writeTo(Object src, Class<?> aClass, Type type, Annotation[] annotations, MediaType mediaType,
            MultivaluedMap<String, Object> stringObjectMultivaluedMap, OutputStream outputStream)
            throws IOException {
        JsonWriter writer = new JsonWriter(new OutputStreamWriter(outputStream, Charset.forName(UTF_8)));
        gson.toJson(src, type, writer);
        writer.close();
    }
}