SerializableFunctionSnippet.java

Pipeline pipeline = Pipeline.create(options);
pipeline
        .apply("Read_file_from_GCS",
                TextIO.read().from("gs:bucket_name/some_file.csv"))
        .apply("Transform_file",
                ParDo.of(doFn))
        .apply("Write_results_to_BQ_table_partition_by_date",
                BigQueryIO.writeTableRows()
                        .to((SerializableFunction<ValueInSingleWindow<TableRow>, TableDestination>) element -> {
                            TableRow row = element.getValue();
                            String table = row.get("section").toString();
                            String destination = String.format("%s:%s.%s", project, dataset, table);
                            return new TableDestination(destination, destination);
                        })
                        .withCreateDisposition(CREATE_IF_NEEDED)
                        .withWriteDisposition(WRITE_APPEND)
                        .withSchema(schema));
pipeline.run();