Java tutorial
/* * JBoss, Home of Professional Open Source. * See the COPYRIGHT.txt file distributed with this work for information * regarding copyright ownership. Some portions may be licensed * to Red Hat, Inc. under one or more contributor license agreements. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA * 02110-1301 USA. */ package org.komodo.rest.relational.json; import static org.komodo.rest.relational.json.KomodoJsonMarshaller.BUILDER; import java.io.IOException; import java.lang.reflect.Type; import java.util.Arrays; import java.util.Map; import org.komodo.rest.RestBasicEntity; import org.komodo.rest.RestLink; import org.komodo.rest.RestProperty; import org.komodo.rest.json.JsonConstants; import org.komodo.utils.StringUtils; import com.google.gson.TypeAdapter; import com.google.gson.reflect.TypeToken; import com.google.gson.stream.JsonReader; import com.google.gson.stream.JsonWriter; /** * A GSON serializer/deserializer for the Komodo REST objects. * * @param <T> * the {@link RestBasicEntity} subclass */ public abstract class AbstractEntitySerializer<T extends RestBasicEntity> extends TypeAdapter<T> implements JsonConstants { protected static final Type BOOLEAN_MAP_TYPE = new TypeToken<Map<String, Boolean>>() { /* nothing to do */}.getType(); protected static final Type STRING_MAP_TYPE = new TypeToken<Map<String, String>>() { /* nothing to do */}.getType(); protected void beginRead(final JsonReader in) throws IOException { in.beginObject(); } protected void beginWrite(final JsonWriter out) throws IOException { out.beginObject(); } protected void endRead(final JsonReader in) throws IOException { in.endObject(); } protected void endWrite(final JsonWriter out) throws IOException { out.endObject(); } /** * {@inheritDoc} * * @see com.google.gson.TypeAdapter#read(com.google.gson.stream.JsonReader) */ @Override public abstract T read(final JsonReader in) throws IOException; protected void readProperties(final JsonReader in, final T value) { final RestProperty[] props = BUILDER.fromJson(in, RestProperty[].class); if (props == null) value.setProperties(null); else value.setProperties(Arrays.asList(props)); } protected void readLinks(final JsonReader in, final T value) { final RestLink[] links = BUILDER.fromJson(in, RestLink[].class); value.setLinks(Arrays.asList(links)); } /** * {@inheritDoc} * * @see com.google.gson.TypeAdapter#write(com.google.gson.stream.JsonWriter, java.lang.Object) */ @Override public abstract void write(final JsonWriter out, final T value) throws IOException; protected void writeProperties(final JsonWriter out, final T value) throws IOException { if (value.getProperties().isEmpty()) return; out.name(JsonConstants.PROPERTIES); BUILDER.toJson(value.getProperties().toArray(new RestProperty[0]), RestProperty[].class, out); } protected void writeLinks(final JsonWriter out, final T value) throws IOException { if (value.getLinks().size() != 0) { out.name(JsonConstants.LINKS); BUILDER.toJson(value.getLinks().toArray(new RestLink[0]), RestLink[].class, out); } } /** * @param entity the entity * @return true if entity's id, data path and kType have been populated, false otherwise */ protected boolean isComplete(T entity) { return !StringUtils.isBlank(entity.getId()) && !StringUtils.isBlank(entity.getDataPath()) && entity.getkType() != null; } }