exceptionfactory commented on code in PR #9064: URL: https://github.com/apache/nifi/pull/9064#discussion_r1674201346
########## nifi-extension-bundles/nifi-poi-bundle/nifi-poi-services/src/main/java/org/apache/nifi/excel/ExcelHeaderSchemaStrategy.java: ########## @@ -0,0 +1,158 @@ +/* + * 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.nifi.excel; + +import org.apache.commons.lang3.math.NumberUtils; +import org.apache.nifi.components.AllowableValue; +import org.apache.nifi.context.PropertyContext; +import org.apache.nifi.logging.ComponentLog; +import org.apache.nifi.schema.access.SchemaAccessStrategy; +import org.apache.nifi.schema.access.SchemaField; +import org.apache.nifi.schema.access.SchemaNotFoundException; +import org.apache.nifi.schema.inference.FieldTypeInference; +import org.apache.nifi.schema.inference.TimeValueInference; +import org.apache.nifi.serialization.SimpleRecordSchema; +import org.apache.nifi.serialization.record.DataType; +import org.apache.nifi.serialization.record.RecordField; +import org.apache.nifi.serialization.record.RecordSchema; +import org.apache.nifi.util.SchemaInferenceUtil; +import org.apache.poi.ss.usermodel.Cell; +import org.apache.poi.ss.usermodel.DataFormatter; +import org.apache.poi.ss.usermodel.Row; + +import java.io.IOException; +import java.io.InputStream; +import java.util.ArrayList; +import java.util.EnumSet; +import java.util.LinkedHashMap; +import java.util.List; +import java.util.Locale; +import java.util.Map; +import java.util.Set; +import java.util.stream.Collectors; +import java.util.stream.IntStream; + +public class ExcelHeaderSchemaStrategy implements SchemaAccessStrategy { + private static final Set<SchemaField> schemaFields = EnumSet.noneOf(SchemaField.class); + static final int NUM_ROWS_TO_DETERMINE_TYPES = 10; // NOTE: This number is arbitrary. + static final AllowableValue HEADER_DERIVED = new AllowableValue("Use Starting Row", "Use Starting Row", Review Comment: Recommend changing the variable name to reflect the value: ```suggestion static final AllowableValue USE_STARTING_ROW = new AllowableValue("Use Starting Row", "Use Starting Row", ``` ########## nifi-extension-bundles/nifi-poi-bundle/nifi-poi-services/src/main/java/org/apache/nifi/excel/ExcelHeaderSchemaStrategy.java: ########## @@ -0,0 +1,158 @@ +/* + * 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.nifi.excel; + +import org.apache.commons.lang3.math.NumberUtils; +import org.apache.nifi.components.AllowableValue; +import org.apache.nifi.context.PropertyContext; +import org.apache.nifi.logging.ComponentLog; +import org.apache.nifi.schema.access.SchemaAccessStrategy; +import org.apache.nifi.schema.access.SchemaField; +import org.apache.nifi.schema.access.SchemaNotFoundException; +import org.apache.nifi.schema.inference.FieldTypeInference; +import org.apache.nifi.schema.inference.TimeValueInference; +import org.apache.nifi.serialization.SimpleRecordSchema; +import org.apache.nifi.serialization.record.DataType; +import org.apache.nifi.serialization.record.RecordField; +import org.apache.nifi.serialization.record.RecordSchema; +import org.apache.nifi.util.SchemaInferenceUtil; +import org.apache.poi.ss.usermodel.Cell; +import org.apache.poi.ss.usermodel.DataFormatter; +import org.apache.poi.ss.usermodel.Row; + +import java.io.IOException; +import java.io.InputStream; +import java.util.ArrayList; +import java.util.EnumSet; +import java.util.LinkedHashMap; +import java.util.List; +import java.util.Locale; +import java.util.Map; +import java.util.Set; +import java.util.stream.Collectors; +import java.util.stream.IntStream; + +public class ExcelHeaderSchemaStrategy implements SchemaAccessStrategy { + private static final Set<SchemaField> schemaFields = EnumSet.noneOf(SchemaField.class); + static final int NUM_ROWS_TO_DETERMINE_TYPES = 10; // NOTE: This number is arbitrary. + static final AllowableValue HEADER_DERIVED = new AllowableValue("Use Starting Row", "Use Starting Row", + "The configured first row of the Excel file is a header line that contains the names of the columns. The schema will be derived by using the " + + "column names in the header and the following " + NUM_ROWS_TO_DETERMINE_TYPES + " rows to determine the type(s) of each column"); + + private final PropertyContext context; + private final ComponentLog logger; + private final TimeValueInference timeValueInference; + private final DataFormatter dataFormatter; + + public ExcelHeaderSchemaStrategy(PropertyContext context, ComponentLog logger, TimeValueInference timeValueInference, Locale locale) { + this.context = context; + this.logger = logger; + this.timeValueInference = timeValueInference; + this.dataFormatter = locale == null ? new DataFormatter() : new DataFormatter(locale); + } + + @Override + public RecordSchema getSchema(Map<String, String> variables, InputStream contentStream, RecordSchema readSchema) throws SchemaNotFoundException, IOException { + if (this.context == null) { + throw new SchemaNotFoundException("Schema Access Strategy intended only for validation purposes and cannot obtain schema"); + } + + final String requiredSheetsDelimited = context.getProperty(ExcelReader.REQUIRED_SHEETS).evaluateAttributeExpressions(variables).getValue(); + final List<String> requiredSheets = ExcelReader.getRequiredSheets(requiredSheetsDelimited); + final Integer rawFirstRow = context.getProperty(ExcelReader.STARTING_ROW).evaluateAttributeExpressions(variables).asInteger(); + final int firstRow = rawFirstRow == null ? NumberUtils.toInt(ExcelReader.STARTING_ROW.getDefaultValue()) : rawFirstRow; + final int zeroBasedFirstRow = ExcelReader.getZeroBasedIndex(firstRow); + final String password = context.getProperty(ExcelReader.PASSWORD).getValue(); + final ExcelRecordReaderConfiguration configuration = new ExcelRecordReaderConfiguration.Builder() + .withRequiredSheets(requiredSheets) + .withFirstRow(zeroBasedFirstRow) + .withPassword(password) + .build(); + + final RowIterator rowIterator = new RowIterator(contentStream, configuration, logger); + final Map<String, FieldTypeInference> typeMap = new LinkedHashMap<>(); + List<String> fieldNames = null; + int index = 0; + + while (rowIterator.hasNext()) { + Row row = rowIterator.next(); + if (index == 0) { + fieldNames = getFieldNames(firstRow, row); + } else if (index <= NUM_ROWS_TO_DETERMINE_TYPES) { + inferSchema(row, fieldNames, typeMap); + } else { + break; + } + + index++; + } + + return createSchema(typeMap); + } + + private List<String> getFieldNames(int firstRowIndex, Row row) throws SchemaNotFoundException { + if (!ExcelUtils.hasCells(row)) { + throw new SchemaNotFoundException(String.format("Field names could not be determined from configured header row %s, as this row has no cells with data", firstRowIndex)); + } + + final List<String> fieldNames = new ArrayList<>(); + for (int index = 0; index < row.getLastCellNum(); index++) { + final Cell cell = row.getCell(index); + final String fieldName = dataFormatter.formatCellValue(cell); + + if (fieldName == null || fieldName.isEmpty()) { + throw new SchemaNotFoundException(String.format("Configured header row %s at cell %s is empty which is not suitable for a field name", row.getRowNum(), index)); + } + + fieldNames.add(fieldName); + } + + return fieldNames; + } + + private void inferSchema(final Row row, final List<String> fieldNames, final Map<String, FieldTypeInference> typeMap) throws SchemaNotFoundException { + if (!ExcelUtils.hasCells(row)) { + throw new SchemaNotFoundException(String.format("Row %s a required row for inferring field types has no cells", row.getRowNum())); Review Comment: This check effectively requires a minimum of 10 rows, which should not be necessary. Instead of requiring 10 rows and requiring a matching number of cells, it seems better to make this method more permissive. That would allow less than 10 rows, and it would allow some empty or partial rows, but that seems acceptable because the type inference is a best-effort approach. ########## nifi-extension-bundles/nifi-poi-bundle/nifi-poi-services/src/main/java/org/apache/nifi/excel/ExcelHeaderSchemaStrategy.java: ########## @@ -0,0 +1,158 @@ +/* + * 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.nifi.excel; + +import org.apache.commons.lang3.math.NumberUtils; +import org.apache.nifi.components.AllowableValue; +import org.apache.nifi.context.PropertyContext; +import org.apache.nifi.logging.ComponentLog; +import org.apache.nifi.schema.access.SchemaAccessStrategy; +import org.apache.nifi.schema.access.SchemaField; +import org.apache.nifi.schema.access.SchemaNotFoundException; +import org.apache.nifi.schema.inference.FieldTypeInference; +import org.apache.nifi.schema.inference.TimeValueInference; +import org.apache.nifi.serialization.SimpleRecordSchema; +import org.apache.nifi.serialization.record.DataType; +import org.apache.nifi.serialization.record.RecordField; +import org.apache.nifi.serialization.record.RecordSchema; +import org.apache.nifi.util.SchemaInferenceUtil; +import org.apache.poi.ss.usermodel.Cell; +import org.apache.poi.ss.usermodel.DataFormatter; +import org.apache.poi.ss.usermodel.Row; + +import java.io.IOException; +import java.io.InputStream; +import java.util.ArrayList; +import java.util.EnumSet; +import java.util.LinkedHashMap; +import java.util.List; +import java.util.Locale; +import java.util.Map; +import java.util.Set; +import java.util.stream.Collectors; +import java.util.stream.IntStream; + +public class ExcelHeaderSchemaStrategy implements SchemaAccessStrategy { + private static final Set<SchemaField> schemaFields = EnumSet.noneOf(SchemaField.class); + static final int NUM_ROWS_TO_DETERMINE_TYPES = 10; // NOTE: This number is arbitrary. + static final AllowableValue HEADER_DERIVED = new AllowableValue("Use Starting Row", "Use Starting Row", + "The configured first row of the Excel file is a header line that contains the names of the columns. The schema will be derived by using the " + + "column names in the header and the following " + NUM_ROWS_TO_DETERMINE_TYPES + " rows to determine the type(s) of each column"); + + private final PropertyContext context; + private final ComponentLog logger; + private final TimeValueInference timeValueInference; + private final DataFormatter dataFormatter; + + public ExcelHeaderSchemaStrategy(PropertyContext context, ComponentLog logger, TimeValueInference timeValueInference, Locale locale) { + this.context = context; + this.logger = logger; + this.timeValueInference = timeValueInference; + this.dataFormatter = locale == null ? new DataFormatter() : new DataFormatter(locale); + } + + @Override + public RecordSchema getSchema(Map<String, String> variables, InputStream contentStream, RecordSchema readSchema) throws SchemaNotFoundException, IOException { + if (this.context == null) { + throw new SchemaNotFoundException("Schema Access Strategy intended only for validation purposes and cannot obtain schema"); + } + + final String requiredSheetsDelimited = context.getProperty(ExcelReader.REQUIRED_SHEETS).evaluateAttributeExpressions(variables).getValue(); + final List<String> requiredSheets = ExcelReader.getRequiredSheets(requiredSheetsDelimited); + final Integer rawFirstRow = context.getProperty(ExcelReader.STARTING_ROW).evaluateAttributeExpressions(variables).asInteger(); + final int firstRow = rawFirstRow == null ? NumberUtils.toInt(ExcelReader.STARTING_ROW.getDefaultValue()) : rawFirstRow; + final int zeroBasedFirstRow = ExcelReader.getZeroBasedIndex(firstRow); + final String password = context.getProperty(ExcelReader.PASSWORD).getValue(); + final ExcelRecordReaderConfiguration configuration = new ExcelRecordReaderConfiguration.Builder() + .withRequiredSheets(requiredSheets) + .withFirstRow(zeroBasedFirstRow) + .withPassword(password) + .build(); + + final RowIterator rowIterator = new RowIterator(contentStream, configuration, logger); + final Map<String, FieldTypeInference> typeMap = new LinkedHashMap<>(); + List<String> fieldNames = null; + int index = 0; + + while (rowIterator.hasNext()) { + Row row = rowIterator.next(); + if (index == 0) { + fieldNames = getFieldNames(firstRow, row); + } else if (index <= NUM_ROWS_TO_DETERMINE_TYPES) { + inferSchema(row, fieldNames, typeMap); + } else { + break; + } + + index++; + } + + return createSchema(typeMap); + } + + private List<String> getFieldNames(int firstRowIndex, Row row) throws SchemaNotFoundException { + if (!ExcelUtils.hasCells(row)) { + throw new SchemaNotFoundException(String.format("Field names could not be determined from configured header row %s, as this row has no cells with data", firstRowIndex)); + } + + final List<String> fieldNames = new ArrayList<>(); + for (int index = 0; index < row.getLastCellNum(); index++) { + final Cell cell = row.getCell(index); + final String fieldName = dataFormatter.formatCellValue(cell); + + if (fieldName == null || fieldName.isEmpty()) { + throw new SchemaNotFoundException(String.format("Configured header row %s at cell %s is empty which is not suitable for a field name", row.getRowNum(), index)); Review Comment: This check requires more strict enforcement of a header row, but in some cases, an individual cell could be empty. Rather than throwing an error, it seems better to use a generated field name based on the cell number, such as `column_0` like the `ExcelSchemaInference` class. ########## nifi-extension-bundles/nifi-poi-bundle/nifi-poi-services/src/main/java/org/apache/nifi/excel/ExcelHeaderSchemaStrategy.java: ########## @@ -0,0 +1,158 @@ +/* + * 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.nifi.excel; + +import org.apache.commons.lang3.math.NumberUtils; +import org.apache.nifi.components.AllowableValue; +import org.apache.nifi.context.PropertyContext; +import org.apache.nifi.logging.ComponentLog; +import org.apache.nifi.schema.access.SchemaAccessStrategy; +import org.apache.nifi.schema.access.SchemaField; +import org.apache.nifi.schema.access.SchemaNotFoundException; +import org.apache.nifi.schema.inference.FieldTypeInference; +import org.apache.nifi.schema.inference.TimeValueInference; +import org.apache.nifi.serialization.SimpleRecordSchema; +import org.apache.nifi.serialization.record.DataType; +import org.apache.nifi.serialization.record.RecordField; +import org.apache.nifi.serialization.record.RecordSchema; +import org.apache.nifi.util.SchemaInferenceUtil; +import org.apache.poi.ss.usermodel.Cell; +import org.apache.poi.ss.usermodel.DataFormatter; +import org.apache.poi.ss.usermodel.Row; + +import java.io.IOException; +import java.io.InputStream; +import java.util.ArrayList; +import java.util.EnumSet; +import java.util.LinkedHashMap; +import java.util.List; +import java.util.Locale; +import java.util.Map; +import java.util.Set; +import java.util.stream.Collectors; +import java.util.stream.IntStream; + +public class ExcelHeaderSchemaStrategy implements SchemaAccessStrategy { Review Comment: I recommend changing the `getDefaultSchemaAccessStrategy` to return this value as it is likely to be preferred over other alternatives. -- This is an automated message from the Apache Git Service. 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