JsonbProvider.java

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 2017 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * http://glassfish.java.net/public/CDDL+GPL_1_1.html
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 * file and include the License file at packager/legal/LICENSE.txt.
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 * GPL Classpath Exception:
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 *
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package org.glassfish.jersey.jsonb.internal;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;

import javax.ws.rs.ProcessingException;
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.ext.ContextResolver;
import javax.ws.rs.ext.Providers;

import javax.json.bind.Jsonb;
import javax.json.bind.JsonbBuilder;
import javax.json.bind.JsonbException;

import org.glassfish.jersey.jsonb.LocalizationMessages;
import org.glassfish.jersey.message.internal.AbstractMessageReaderWriterProvider;

/**
 * Entity provider (reader and writer) for JSONB.
 */
public class JsonbProvider extends AbstractMessageReaderWriterProvider<Object> {

    private Providers providers;

    public JsonbProvider(@Context Providers providers) {
        this.providers = providers;
    }

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

    @Override
    public Object readFrom(Class<Object> type, Type genericType,
                           Annotation[] annotations,
                           MediaType mediaType,
                           MultivaluedMap<String, String> httpHeaders,
                           InputStream entityStream) throws IOException, WebApplicationException {
        Jsonb jsonb = getJsonb(type);
        try {
            return jsonb.fromJson(entityStream, genericType);
        } catch (JsonbException e) {
            throw new ProcessingException(LocalizationMessages.ERROR_JSONB_DESERIALIZATION(), e);
        }
    }

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

    @Override
    public void writeTo(Object o, Class<?> type, Type genericType,
                        Annotation[] annotations,
                        MediaType mediaType,
                        MultivaluedMap<String, Object> httpHeaders,
                        OutputStream entityStream) throws IOException, WebApplicationException {
        Jsonb jsonb = getJsonb(type);
        try {
            entityStream.write(jsonb.toJson(o).getBytes(AbstractMessageReaderWriterProvider.getCharset(mediaType)));
            entityStream.flush();
        } catch (IOException e) {
            throw new ProcessingException(LocalizationMessages.ERROR_JSONB_SERIALIZATION(), e);
        }

    }

    private Jsonb getJsonb(Class<?> type) {
        final ContextResolver<Jsonb> contextResolver = providers.getContextResolver(Jsonb.class, MediaType.APPLICATION_JSON_TYPE);
        if (contextResolver != null) {
            return contextResolver.getContext(type);
        } else {
            return JsonbSingleton.INSTANCE.getInstance();
        }
    }

    private enum JsonbSingleton {
        INSTANCE;

        private Jsonb jsonbInstance;

        Jsonb getInstance() {
            return jsonbInstance;
        }

        JsonbSingleton() {
            this.jsonbInstance = JsonbBuilder.create();
        }
    }
}