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/*
* Copyright (c) 2015 Red Hat, Inc. and/or its affiliates.
*
* This program and the accompanying materials are made
* available under the terms of the Eclipse Public License 2.0
* which is available at https://www.eclipse.org/legal/epl-2.0/
*
* SPDX-License-Identifier: EPL-2.0
*/
package org.jberet.support.io;
import java.io.Serializable;
import java.util.List;
import java.util.Map;
import org.jberet.support._private.SupportLogger;
import org.jberet.support._private.SupportMessages;
import com.fasterxml.jackson.core.JsonToken;
import com.fasterxml.jackson.dataformat.csv.CsvParser;
import com.fasterxml.jackson.dataformat.csv.CsvSchema;
import jakarta.batch.api.BatchProperty;
import jakarta.batch.api.chunk.ItemReader;
import jakarta.enterprise.context.Dependent;
import jakarta.inject.Inject;
import jakarta.inject.Named;
/**
* An implementation of {@code jakarta.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)
*
* 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,
*
*
* ALLOW_COMMENTS=true, ALLOW_YAML_COMMENTS=true, ALLOW_NUMERIC_LEADING_ZEROS=true, STRICT_DUPLICATE_DETECTION=true
*
*
* @see "com.fasterxml.jackson.core.JsonParser.Feature"
*/
@Inject
@BatchProperty
protected Map 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,
*
*
* TRIM_SPACES=false, WRAP_AS_ARRAY=false
*
*
* @see "com.fasterxml.jackson.dataformat.csv.CsvParser.Feature"
*/
@Inject
@BatchProperty
protected Map 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,
*
*
* org.jberet.support.io.JsonItemReaderTest$UnknownHandler, org.jberet.support.io.JsonItemReaderTest$UnknownHandler2
*
*
* @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,
*
*
* org.jberet.support.io.JsonItemReaderTest$NoopInputDecorator
*
*
* @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 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;
}
}
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