/*
 * 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.
 */
/**
 * Defines {@link org.apache.beam.sdk.coders.Coder Coders}
 * to specify how data is encoded to and decoded from byte strings.
 *
 * <p>During execution of a Pipeline, elements in a
 * {@link org.apache.beam.sdk.values.PCollection}
 * may need to be encoded into byte strings.
 * This happens both at the beginning and end of a pipeline when data is read from and written to
 * persistent storage and also during execution of a pipeline when elements are communicated between
 * machines.
 *
 * <p>Exactly when PCollection elements are encoded during execution depends on which
 * {@link org.apache.beam.sdk.PipelineRunner} is being used and how that runner
 * chooses to execute the pipeline. As such, Beam requires that all PCollections have an
 * appropriate Coder in case it becomes necessary. In many cases, the Coder can be inferred from
 * the available Java type
 * information and the Pipeline's {@link org.apache.beam.sdk.coders.CoderRegistry}. It
 * can be specified per PCollection via
 * {@link org.apache.beam.sdk.values.PCollection#setCoder(Coder)} or per type using the
 * {@link org.apache.beam.sdk.coders.DefaultCoder} annotation.
 *
 * <p>This package provides a number of coders for common types like {@code Integer},
 * {@code String}, and {@code List}, as well as coders like
 * {@link org.apache.beam.sdk.coders.AvroCoder} that can be used to encode many custom
 * types.
 *
 */
package org.apache.beam.sdk.coders;