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/* * Copyright (c) 2015 Red Hat, Inc. and/or its affiliates. * * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * Cheng Fang - Initial API and implementation */ package org.jberet.support.io; import java.io.Serializable; import java.util.List; import java.util.Map; import javax.batch.api.BatchProperty; import javax.batch.api.chunk.ItemReader; import javax.enterprise.context.Dependent; import javax.inject.Inject; import javax.inject.Named; import com.fasterxml.jackson.core.JsonToken; import com.fasterxml.jackson.dataformat.csv.CsvParser; import com.fasterxml.jackson.dataformat.csv.CsvSchema; import org.jberet.support._private.SupportLogger; import org.jberet.support._private.SupportMessages; /** * An implementation of {@code javax.batch.api.chunk.ItemReader} that reads data items from CSV files using jackson-dataformat-csv. * * @see CsvItemReader * @see JacksonCsvItemWriter * @see JacksonCsvItemReaderWriterBase * @since 1.2.0 */ @Named @Dependent public class JacksonCsvItemReader extends JacksonCsvItemReaderWriterBase implements ItemReader { /** * Specifies the start position (a positive integer starting from 1) to read the data. If reading from the beginning * of the input CSV resource, there is no need to specify this property. */ @Inject @BatchProperty protected int start; /** * Specify the end position in the data set (inclusive). Optional property, and defaults to {@code Integer.MAX_VALUE}. * If reading till the end of the input CSV resource, there is no need to specify this property. */ @Inject @BatchProperty protected int end; /** * Whether the first data line (either first line of the document, if useHeader=false, or second, if useHeader=true) * should be completely ignored by parser. Needed to support CSV-like file formats that include additional * non-data content before real data begins (specifically some database dumps do this) * <p/> * Optional property, valid values are "true" and "false" and defaults to "false". * * @see "com.fasterxml.jackson.dataformat.csv.CsvSchema" */ @Inject @BatchProperty protected String skipFirstDataRow; /** * Character, if any, used to escape values. Most commonly defined as backslash ('\'). Only used by parser; * generator only uses quoting, including doubling up of quotes to indicate quote char itself. * Optional protected and defaults to null. * * @see "com.fasterxml.jackson.dataformat.csv.CsvSchema" */ @Inject @BatchProperty protected String escapeChar; /** * A comma-separated list of key-value pairs that specify {@code com.fasterxml.jackson.core.JsonParser} features. * Optional property and defaults to null. For example, * <p/> * <pre> * ALLOW_COMMENTS=true, ALLOW_YAML_COMMENTS=true, ALLOW_NUMERIC_LEADING_ZEROS=true, STRICT_DUPLICATE_DETECTION=true * </pre> * * @see "com.fasterxml.jackson.core.JsonParser.Feature" */ @Inject @BatchProperty protected Map<String, String> jsonParserFeatures; /** * A comma-separated list of key-value pairs that specify {@code com.fasterxml.jackson.dataformat.csv.CsvParser.Feature}. * Optional property and defaults to null. For example, * <p/> * <pre> * TRIM_SPACES=false, WRAP_AS_ARRAY=false * </pre> * * @see "com.fasterxml.jackson.dataformat.csv.CsvParser.Feature" */ @Inject @BatchProperty protected Map<String, String> csvParserFeatures; /** * A comma-separated list of fully-qualified names of classes that implement * {@code com.fasterxml.jackson.databind.deser.DeserializationProblemHandler}, which can be registered to get * called when a potentially recoverable problem is encountered during deserialization process. * Handlers can try to resolve the problem, throw an exception or do nothing. Optional property and defaults to null. * For example, * <p/> * <pre> * org.jberet.support.io.JsonItemReaderTest$UnknownHandler, org.jberet.support.io.JsonItemReaderTest$UnknownHandler2 * </pre> * * @see "com.fasterxml.jackson.databind.deser.DeserializationProblemHandler" * @see "com.fasterxml.jackson.databind.ObjectMapper#addHandler(com.fasterxml.jackson.databind.deser.DeserializationProblemHandler)" * @see MappingJsonFactoryObjectFactory#configureDeserializationProblemHandlers(com.fasterxml.jackson.databind.ObjectMapper, java.lang.String, java.lang.ClassLoader) */ @Inject @BatchProperty protected String deserializationProblemHandlers; /** * Fully-qualified name of a class that extends {@code com.fasterxml.jackson.core.io.InputDecorator}, which can be * used to decorate input sources. Typical use is to use a filter abstraction (filtered stream, reader) * around original input source, and apply additional processing during read operations. Optional property and * defaults to null. For example, * <p/> * <pre> * org.jberet.support.io.JsonItemReaderTest$NoopInputDecorator * </pre> * * @see "com.fasterxml.jackson.core.JsonFactory#setInputDecorator(com.fasterxml.jackson.core.io.InputDecorator)" * @see "com.fasterxml.jackson.core.io.InputDecorator" */ @Inject @BatchProperty protected Class inputDecorator; private CsvParser csvParser; private int rowNumber; private boolean rawAccess; @Override public void open(final Serializable checkpoint) throws Exception { if (end == 0) { end = Integer.MAX_VALUE; } if (checkpoint != null) { start = (Integer) checkpoint; } if (start > end) { throw SupportMessages.MESSAGES.invalidStartPosition((Integer) checkpoint, start, end); } init(); csvParser = (CsvParser) JsonItemReader.configureJsonParser(this, inputDecorator, deserializationProblemHandlers, jsonParserFeatures); if (csvParserFeatures != null) { for (final Map.Entry<String, String> e : csvParserFeatures.entrySet()) { final String key = e.getKey(); final String value = e.getValue(); final CsvParser.Feature feature; try { feature = CsvParser.Feature.valueOf(key); } catch (final Exception e1) { throw SupportMessages.MESSAGES.unrecognizedReaderWriterProperty(key, value); } if ("true".equals(value)) { if (!feature.enabledByDefault()) { csvParser.configure(feature, true); } } else if ("false".equals(value)) { if (feature.enabledByDefault()) { csvParser.configure(feature, false); } } else { throw SupportMessages.MESSAGES.invalidReaderWriterProperty(null, value, key); } } } rawAccess = beanType == List.class || beanType == String[].class; if (!rawAccess) { CsvSchema schema; if (columns != null) { schema = buildCsvSchema(null); } else { //columns not defined, but beanType is either Map.class or Pojo.class or JsonNode.class if (useHeader) { schema = buildCsvSchema(CsvSchema.emptySchema()); } else { throw SupportMessages.MESSAGES.invalidReaderWriterProperty(null, columns, "columns"); } } if (escapeChar != null) { schema = schema.withEscapeChar(escapeChar.charAt(0)); } if (skipFirstDataRow != null) { schema = schema.withSkipFirstDataRow(Boolean.parseBoolean(skipFirstDataRow.trim())); } csvParser.setSchema(schema); } } @Override public void close() throws Exception { if (csvParser != null) { SupportLogger.LOGGER.closingResource(resource, this.getClass()); if (deserializationProblemHandlers != null) { objectMapper.clearProblemHandlers(); } csvParser.close(); csvParser = null; } } @Override public Object readItem() throws Exception { if (rowNumber >= end) { return null; } JsonToken token; final Object readValue; if (!rawAccess) { do { token = csvParser.nextToken(); if (token == null) { return null; } if (token == JsonToken.START_OBJECT) { if (++rowNumber >= start) { break; } } } while (true); readValue = objectMapper.readValue(csvParser, beanType); if (!skipBeanValidation) { ItemReaderWriterBase.validate(readValue); } } else { do { token = csvParser.nextToken(); if (token == null) { return null; } if (token == JsonToken.START_ARRAY) { if (++rowNumber >= start) { break; } } } while (true); readValue = objectMapper.readValue(csvParser, beanType); } return readValue; } /** * Gets the current row number in the {@code ResultSet} as the checkpoint info. * * @return the current row number in the {@code ResultSet} * @throws Exception any exception raised */ @Override public Serializable checkpointInfo() throws Exception { return rowNumber; } }