afedulov commented on a change in pull request #17598: URL: https://github.com/apache/flink/pull/17598#discussion_r770126659
########## File path: flink-formats/flink-csv/src/main/java/org/apache/flink/formats/csv/CsvFormat.java ########## @@ -0,0 +1,144 @@ +/* + * 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.flink.formats.csv; + +import org.apache.flink.annotation.PublicEvolving; +import org.apache.flink.api.common.typeinfo.TypeInformation; +import org.apache.flink.configuration.Configuration; +import org.apache.flink.connector.file.src.reader.SimpleStreamFormat; +import org.apache.flink.connector.file.src.reader.StreamFormat; +import org.apache.flink.core.fs.FSDataInputStream; +import org.apache.flink.formats.common.Converter; + +import org.apache.flink.shaded.jackson2.com.fasterxml.jackson.databind.MappingIterator; +import org.apache.flink.shaded.jackson2.com.fasterxml.jackson.dataformat.csv.CsvMapper; +import org.apache.flink.shaded.jackson2.com.fasterxml.jackson.dataformat.csv.CsvSchema; + +import javax.annotation.Nullable; + +import java.io.IOException; + +import static org.apache.flink.util.Preconditions.checkNotNull; + +/** + * A {@code StreamFormat} for reading CSV files. + * + * @param <T> + */ +@PublicEvolving +public class CsvFormat<T> extends SimpleStreamFormat<T> { + + private static final long serialVersionUID = 1L; + + private final CsvMapper mapper; + private final CsvSchema schema; + private final Class<Object> rootType; + private final Converter<Object, T, Void> converter; + private final TypeInformation<T> typeInformation; + + @SuppressWarnings("unchecked") + <R> CsvFormat( + CsvMapper mapper, + CsvSchema schema, + Class<R> rootType, + Converter<R, T, Void> converter, + TypeInformation<T> typeInformation) { + this.mapper = checkNotNull(mapper); + this.schema = schema; + this.rootType = (Class<Object>) checkNotNull(rootType); + this.typeInformation = checkNotNull(typeInformation); + this.converter = (Converter<Object, T, Void>) checkNotNull(converter); + } + + /** + * Builds a new {@code CsvFormat} using a {@code CsvSchema}. + * + * @param schema The Jackson CSV schema configured for parsing specific CSV files. + * @param typeInformation The Flink type descriptor of the returned elements. + * @param <T> The type of the returned elements. + */ + public static <T> CsvFormat<T> from(CsvSchema schema, TypeInformation<T> typeInformation) { + return from(new CsvMapper(), schema, typeInformation); + } + + /** + * Builds a new {@code CsvFormat} using a {@code CsvSchema} and a pre-created {@code CsvMapper}. + * + * @param mapper The pre-created {@code CsvMapper}. + * @param schema The Jackson CSV schema configured for parsing specific CSV files. + * @param typeInformation The Flink type descriptor of the returned elements. + * @param <T> The type of the returned elements. + */ + public static <T> CsvFormat<T> from( + CsvMapper mapper, CsvSchema schema, TypeInformation<T> typeInformation) { + return new CsvFormat<>( + mapper, + schema, + typeInformation.getTypeClass(), + (value, context) -> value, + typeInformation); + } + + /** + * Builds a new {@code CsvFormat} for reading CSV files mapped to the provided POJO class + * definition. + * + * @param pojoType The type class of the POJO. + * @param <T> The type of the returned elements. + */ + public static <T> CsvFormat<T> from(Class<T> pojoType) { + CsvMapper mapper = new CsvMapper(); + return from(mapper, mapper.schemaFor(pojoType), TypeInformation.of(pojoType)); + } + + @Override + public StreamFormat.Reader<T> createReader(Configuration config, FSDataInputStream stream) + throws IOException { + return new Reader<>(mapper.readerFor(rootType).with(schema).readValues(stream), converter); + } + + @Override + public TypeInformation<T> getProducedType() { + return typeInformation; + } + + // ------------------------------------------------------------------------ + + /** The actual reader for the {@code CsvFormat}. */ + public static final class Reader<R, T> implements StreamFormat.Reader<T> { Review comment: Good point. Copy-paste error from the `TextLineFormat` format "template". -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
