org.apache.apex.malhar.lib.utils.serde.ArraySerde.java Source code

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Here is the source code for org.apache.apex.malhar.lib.utils.serde.ArraySerde.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.apex.malhar.lib.utils.serde;

import java.lang.reflect.Array;

import com.esotericsoftware.kryo.io.Input;
import com.esotericsoftware.kryo.io.Output;
import com.google.common.base.Preconditions;

/**
 * @since 3.6.0
 */
public class ArraySerde<T> implements Serde<T[]> {
    private Serde<T> itemSerde;
    private Class<T> itemType;

    private ArraySerde() {
    }

    /**
     * Serializer and Deserializer need different constructor, so use static factory method to wrap.
     * The ArraySerde returned by newSerializer can only used for serialization
     */
    public static <T> ArraySerde<T> newSerializer(Serde<T> itemSerde) {
        return new ArraySerde<T>(Preconditions.checkNotNull(itemSerde));
    }

    public static <T> ArraySerde<T> newSerde(Serde<T> itemSerde, Class<T> itemType) {
        return new ArraySerde<T>(Preconditions.checkNotNull(itemSerde), Preconditions.checkNotNull(itemType));
    }

    private ArraySerde(Serde<T> itemSerde) {
        this.itemSerde = itemSerde;
    }

    private ArraySerde(Serde<T> itemSerde, Class<T> itemType) {
        this.itemSerde = itemSerde;
        this.itemType = itemType;
    }

    @Override
    public void serialize(T[] objects, Output output) {
        if (objects.length == 0) {
            return;
        }
        output.writeInt(objects.length, true);
        Serde<T> serializer = getItemSerde();
        for (T object : objects) {
            serializer.serialize(object, output);
        }
    }

    protected Serde<T> getItemSerde() {
        return itemSerde;
    }

    @Override
    public T[] deserialize(Input input) {
        int numOfElements = input.readInt(true);

        T[] array = createObjectArray(numOfElements);

        for (int index = 0; index < numOfElements; ++index) {
            array[index] = getItemSerde().deserialize(input);
        }
        return array;
    }

    @SuppressWarnings("unchecked")
    protected T[] createObjectArray(int length) {
        return (T[]) Array.newInstance(itemType, length);
    }
}