org.apache.samza.table.utils.SerdeUtils.java Source code

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Here is the source code for org.apache.samza.table.utils.SerdeUtils.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.samza.table.utils;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.TypeAdapter;
import com.google.gson.stream.JsonReader;
import com.google.gson.stream.JsonWriter;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.lang.reflect.Modifier;
import java.util.Base64;

import org.apache.samza.SamzaException;

public final class SerdeUtils {
    /**
     * Helper method to serialize Java objects as Base64 strings
     * @param name name of the object (for error reporting)
     * @param object object to be serialized
     * @return Base64 representation of the object
     * @param <T> type of the object
     */
    public static <T> String serialize(String name, T object) {
        try (ByteArrayOutputStream baos = new ByteArrayOutputStream();
                ObjectOutputStream oos = new ObjectOutputStream(baos)) {
            oos.writeObject(object);
            return Base64.getEncoder().encodeToString(baos.toByteArray());
        } catch (IOException e) {
            throw new SamzaException("Failed to serialize " + name, e);
        }
    }

    /**
     * Helper method to deserialize Java objects from Base64 strings
     * @param name name of the object (for error reporting)
     * @param strObject base64 string of the serialized object
     * @return deserialized object instance
     * @param <T> type of the object
     */
    @SuppressWarnings("unchecked")
    public static <T> T deserialize(String name, String strObject) {
        try {
            byte[] bytes = Base64.getDecoder().decode(strObject);
            return (T) new ObjectInputStream(new ByteArrayInputStream(bytes)).readObject();
        } catch (Exception e) {
            String errMsg = "Failed to deserialize " + name;
            throw new SamzaException(errMsg, e);
        }
    }

    /**
     * Helper method to serialize Java objects as json strings
     * @param name name of object used for logging
     * @param object object to be serialized
     * @return Json representation of the object
     */
    public static String toJson(String name, Object object) {
        final Gson gson = new GsonBuilder().excludeFieldsWithModifiers(Modifier.TRANSIENT, Modifier.STATIC)
                // Tells Gson how to serialize fields with type of Class.
                .registerTypeHierarchyAdapter(Class.class, new TypeAdapter<Class>() {
                    @Override
                    public void write(JsonWriter out, Class value) throws IOException {
                        if (value == null) {
                            out.nullValue();
                        } else {
                            out.value(value.getName());
                        }
                    }

                    @Override
                    public Class read(JsonReader in) {
                        throw new SamzaException("Deserialization from json is not supported.");
                    }
                }).create();
        try {
            return gson.toJson(object);
        } catch (Exception e) {
            throw new SamzaException(String.format("Failed to serialize %s to json", name), e);
        }
    }
}