com.google.openrtb.json.OpenRtbJsonExtComplexReader.java Source code

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Here is the source code for com.google.openrtb.json.OpenRtbJsonExtComplexReader.java

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/*
 * Copyright 2015 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 static com.google.openrtb.json.OpenRtbJsonUtils.endArray;
import static com.google.openrtb.json.OpenRtbJsonUtils.endObject;
import static com.google.openrtb.json.OpenRtbJsonUtils.startArray;
import static com.google.openrtb.json.OpenRtbJsonUtils.startObject;

import com.fasterxml.jackson.core.JsonLocation;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonToken;
import com.google.protobuf.GeneratedMessage.ExtendableBuilder;
import com.google.protobuf.GeneratedMessage.GeneratedExtension;
import com.google.protobuf.Message;
import java.io.IOException;
import java.util.List;

/**
 * Supports "complex" extensions, where the values are wrapped by a proto Message.
 *
 * @param <EB> Type of message builder being constructed
 * @param <XB> Type of message builder for the extension
 */
public abstract class OpenRtbJsonExtComplexReader<EB extends ExtendableBuilder<?, EB>, XB extends Message.Builder>
        extends OpenRtbJsonExtReader<EB> {
    @SuppressWarnings("rawtypes")
    private final GeneratedExtension key;
    private final boolean isJsonObject;

    /**
     * Use this constructor for readers of message type.
     *
     * @param key Extension key
     * @param isJsonObject {@code true} if the extension value is desserialized from a JSON object
     * @param rootNameFilters Filter for the root names (direct fields of "ext").
     *     If empty, this reader will be invoked for any field.
     */
    protected OpenRtbJsonExtComplexReader(GeneratedExtension<?, ?> key, boolean isJsonObject,
            String... rootNameFilters) {
        super(rootNameFilters);
        this.key = checkNotNull(key);
        this.isJsonObject = isJsonObject;
    }

    @SuppressWarnings("unchecked")
    @Override
    protected final void read(EB msg, JsonParser par) throws IOException {
        Object extObj = msg.getExtension(key);
        if (extObj instanceof Message) {
            readSingle(msg, par, (XB) ((Message) extObj).toBuilder());
        } else if (extObj instanceof List<?>) {
            readRepeated(msg, par);
        } else {
            throw new IllegalStateException("Extension must be Message or repeated Message");
        }
    }

    /**
     * Reads extensions of message type.
     *
     * @param ext Builder for the extension object, where properties will be set
     * @param par JSON parser, positioned at the property to be desserialized
     * {@code false} if the property was ignored, leaving the parser in the same position
     * @throws IOException any parsing error
     */
    protected abstract void read(XB ext, JsonParser par) throws IOException;

    @SuppressWarnings("unchecked")
    private void readSingle(EB msg, JsonParser par, XB ext) throws IOException {
        if (isJsonObject) {
            startObject(par);
        }
        boolean extRead = false;
        JsonToken tokLast = par.getCurrentToken();
        JsonLocation locLast = par.getCurrentLocation();
        while (endObject(par)) {
            read(ext, par);
            if (par.getCurrentToken() != tokLast || !par.getCurrentLocation().equals(locLast)) {
                extRead = true;
                par.nextToken();
                tokLast = par.getCurrentToken();
                locLast = par.getCurrentLocation();
            } else {
                break;
            }
        }
        if (extRead) {
            msg.setExtension(key, ext.build());
        }
        if (isJsonObject) {
            par.nextToken();
        }
    }

    @SuppressWarnings("unchecked")
    private void readRepeated(EB msg, JsonParser par) throws IOException {
        par.nextToken();
        JsonToken tokLast = par.getCurrentToken();
        JsonLocation locLast = par.getCurrentLocation();
        for (startArray(par); endArray(par); par.nextToken()) {
            boolean objRead = false;
            XB ext = (XB) key.getMessageDefaultInstance().toBuilder();
            for (startObject(par); endObject(par); par.nextToken()) {
                read(ext, par);
                JsonToken tokNew = par.getCurrentToken();
                JsonLocation locNew = par.getCurrentLocation();
                if (tokNew != tokLast || !locNew.equals(locLast)) {
                    objRead = true;
                }
                tokLast = tokNew;
                locLast = locNew;
            }
            if (objRead) {
                msg.addExtension(key, ext.build());
            }
        }
    }

    @Override
    public String toString() {
        return super.toString() + (isJsonObject ? " JSON=object" : " JSON=scalar") + " message="
                + key.getDescriptor().getFullName();
    }
}