appdev.letsmeet.control.utils.messgeBodyHandlers.GsonMessageBodyHandler.java Source code

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Here is the source code for appdev.letsmeet.control.utils.messgeBodyHandlers.GsonMessageBodyHandler.java

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package appdev.letsmeet.control.utils.messgeBodyHandlers;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;
import javax.ws.rs.Consumes;
import javax.ws.rs.Produces;
import javax.ws.rs.WebApplicationException;
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;

/**
 *
 * @author HANAN&OLYA
 */
@Provider
@Consumes(MediaType.APPLICATION_JSON)
@Produces(MediaType.APPLICATION_JSON)
public class GsonMessageBodyHandler implements MessageBodyWriter<Object>, MessageBodyReader<Object> {

    private static final String UTF_8 = "UTF-8";
    private Gson gson;

    private Gson getGson() {
        if (gson == null) {
            final GsonBuilder gsonBuilder = new GsonBuilder();
            gson = gsonBuilder.serializeNulls().create();
        }
        return gson;
    }

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

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

    @Override
    public void writeTo(Object t, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType,
            MultivaluedMap<String, Object> httpHeaders, OutputStream entityStream)
            throws IOException, WebApplicationException {

        try (OutputStreamWriter writer = new OutputStreamWriter(entityStream, UTF_8)) {
            Type jsonType;
            if (type.equals(genericType)) {
                jsonType = type;
            } else {
                jsonType = genericType;
            }
            getGson().toJson(t, jsonType, writer);
        }

    }

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

    @Override
    public Object readFrom(Class<Object> type, Type genericType, Annotation[] annotations, MediaType mediaType,
            MultivaluedMap<String, String> httpHeaders, InputStream entityStream)
            throws IOException, WebApplicationException {

        try (InputStreamReader reader = new InputStreamReader(entityStream, UTF_8)) {
            Type jsonType;
            if (type.equals(genericType)) {
                jsonType = type;
            } else {
                jsonType = genericType;
            }
            return getGson().fromJson(reader, jsonType);
        }
    }
}