runners/spark/2/src/main/java/org/apache/beam/runners/spark/structuredstreaming/translation/helpers/EncoderFactory.java

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 * 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
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 * Unless required by applicable law or agreed to in writing, software
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 * See the License for the specific language governing permissions and
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package org.apache.beam.runners.spark.structuredstreaming.translation.helpers;

import org.apache.spark.sql.Encoder;
import org.apache.spark.sql.catalyst.encoders.ExpressionEncoder;
import org.apache.spark.sql.catalyst.expressions.Expression;
import org.apache.spark.sql.catalyst.expressions.objects.StaticInvoke;
import org.apache.spark.sql.types.DataType;
import scala.collection.immutable.List;
import scala.collection.immutable.Nil$;
import scala.collection.mutable.WrappedArray;
import scala.reflect.ClassTag$;

public class EncoderFactory {

  static <T> Encoder<T> create(
      Expression serializer, Expression deserializer, Class<? super T> clazz) {
    // TODO Isolate usage of Scala APIs in utility https://github.com/apache/beam/issues/22382
    List<Expression> serializers = Nil$.MODULE$.$colon$colon(serializer);
    return new ExpressionEncoder<>(
        SchemaHelpers.binarySchema(),
        false,
        serializers,
        deserializer,
        ClassTag$.MODULE$.apply(clazz));
  }

  /**
   * Invoke method {@code fun} on Class {@code cls}, immediately propagating {@code null} if any
   * input arg is {@code null}.
   */
  static Expression invokeIfNotNull(Class<?> cls, String fun, DataType type, Expression... args) {
    return new StaticInvoke(cls, type, fun, new WrappedArray.ofRef<>(args), true, true);
  }
}