/* * Copyright 2014 Google Inc. All Rights Reserved. * * 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.google.openrtb.json; import static com.google.common.base.Preconditions.checkNotNull; import com.fasterxml.jackson.core.JsonGenerator; import java.io.IOException; import java.util.List; /** * A serialization extension, can add children of "ext" fields. * * <p>Implementations of this interface have to be threadsafe. * * @param <T> Type of extension field */ public abstract class OpenRtbJsonExtWriter<T> { private final String rootName; private final boolean isJsonObject; /** * Use this constructor for writers of regular extensions. */ protected OpenRtbJsonExtWriter() { this.rootName = null; this.isJsonObject = false; } /** * Use this constructor for writers of repeated extensions. * * @param rootName Name for the "root" entity: the field that holds an array or the object * @param isJsonObject {@code true} if the extension value is serialized to a JSON object */ protected OpenRtbJsonExtWriter(String rootName, boolean isJsonObject) { this.rootName = checkNotNull(rootName); this.isJsonObject = isJsonObject; } protected final void writeRepeated(List<T> extList, JsonGenerator gen) throws IOException { gen.writeArrayFieldStart(rootName); for (T ext : extList) { if (isJsonObject) { gen.writeStartObject(); } write(ext, gen); if (isJsonObject) { gen.writeEndObject(); } } gen.writeEndArray(); } protected final void writeSingle(T value, JsonGenerator gen) throws IOException { if (isJsonObject) { gen.writeObjectFieldStart(rootName); } write(value, gen); if (isJsonObject) { gen.writeEndObject(); } } /** * Write the fields of an extension value. * * @param value The extension value (scalar field) * @param gen The JSON generator * @throws IOException any serialization error */ protected abstract void write(T value, JsonGenerator gen) throws IOException; @Override public String toString() { return getClass().getName() + (isJsonObject ? " JSON=object" : " JSON=scalar") + (rootName == null ? " regular" : " repeated:" + rootName); } protected final boolean checkRequired(boolean hasProperty) { return hasProperty; } protected final boolean checkRequired(int propertyCount) { return propertyCount != 0; } }