Purecsv framework configuration file Detailed explanation: Customized CSV data processing operation
The PURECSV framework is a Java library for processing CSV data. It provides a simple and flexible way to perform the reading and writing operation of the CSV file.Before using the PureCSV framework for CSV data processing, we need to understand how to configure it to meet our needs.
The configuration file of the PURECSV framework includes two main aspects: reading configuration and writing configuration, we will introduce it in detail.
1. Read configuration
When reading the CSV file with the PureCSV framework, you can specify various reading options by configuration to meet different needs.Here are some commonly used reading configuration options:
-` CSVDELIMITER`: Specify the columns in the CSV file, the default is the comma.
-` CSVQUOTECHAR`: Specify the reference characters in the CSV file, the default is dual quotation marks.
-` Header`: Specify whether the CSV file contains the title line. By default, PureCSV regards the first line as a title line.
-` SKIPEMPTYROWS`: Specify whether to skip the empty line, default to false, and not skip the empty line.
-`maxcharspercolumn`: Specify the maximum number limit of each column, the default is 0, which means no limit.
The following is an example of reading using PureCSV for CSV files, which shows how to use reading configuration:
import com.fasterxml.jackson.databind.MappingIterator;
import com.fasterxml.jackson.dataformat.csv.CsvMapper;
import com.fasterxml.jackson.dataformat.csv.CsvSchema;
import java.io.File;
import java.io.IOException;
public class CsvReaderExample {
public static void main(String[] args) throws IOException {
File csvFile = new File("data.csv");
CsvMapper csvMapper = new CsvMapper();
CsvSchema csvSchema = CsvSchema.builder()
.setUseHeader(true)
.build();
MappingIterator<Object> mappingIterator = csvMapper.readerFor(Object.class)
.with(csvSchema)
.readValues(csvFile);
while (mappingIterator.hasNext()) {
Object data = mappingIterator.next();
// Process the data you read
}
}
}
2. Write configuration
When writing the CSV file with the PurecsV framework, we can specify various writing options by configuration to meet different needs.Here are some commonly used writing configuration options:
-` CSVDELIMITER`: Specify the columns in the CSV file, the default is the comma.
-` CSVQUOTECHAR`: Specify the reference characters in the CSV file, the default is dual quotation marks.
-` `writeheader`: Specify whether to write the title line when writing the CSV file, the default TRUE.
-` `quotellfields`: Specify whether to reference all fields, default to false, and only quote fields containing special characters.
The following is an example of writing using PureCSV for CSV files, which shows how to use the writing configuration:
import com.fasterxml.jackson.dataformat.csv.CsvMapper;
import com.fasterxml.jackson.dataformat.csv.CsvSchema;
import java.io.File;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;
public class CsvWriterExample {
public static void main(String[] args) throws IOException {
File csvFile = new File("output.csv");
List<String> rowData1 = Arrays.asList("John", "Doe", "john.doe@example.com");
List<String> rowData2 = Arrays.asList("Jane", "Smith", "jane.smith@example.com");
CsvMapper csvMapper = new CsvMapper();
CsvSchema csvSchema = csvMapper.schemaFor(String.class).withHeader();
csvMapper.writerFor(List.class)
.with(csvSchema)
.writeValue(csvFile, Arrays.asList(rowData1, rowData2));
}
}
The above is a detailed explanation of the configuration file of the PureCSV framework. Through these configuration options, we can make customized CSV data processing operations according to our own needs.
