Use Apache Commons CSV to implement the batch import and export of data
Using Apache Commons CSV library can simplify the batch import and export operation of the data.CSV (COMMA SEPARATED VALUES) is a commonly used file format that can be stored in a comma separation.The following is an example of the batch import and export of data using Apache Commons CSV to implement data:
1. Import data:
To import the data of the CSV file into the Java application, you can use the Apache Commons CSV library according to the following steps:
First, add the dependency item of the Apache Commons CSV library to the pom.xml file of the project:
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-csv</artifactId>
<version>1.8</version>
</dependency>
Next, read the data from the CSV file with the following code:
import org.apache.commons.csv.CSVFormat;
import org.apache.commons.csv.CSVParser;
import org.apache.commons.csv.CSVRecord;
import java.io.FileReader;
import java.io.IOException;
import java.io.Reader;
public class CSVImporter {
public static void main(String[] args) {
try {
Reader reader = new FileReader("data.csv");
CSVParser csvParser = new CSVParser(reader, CSVFormat.DEFAULT);
for (CSVRecord csvRecord : csvParser) {
String column1 = csvRecord.get(0);
String column2 = csvRecord.get(1);
// Process each line of data
System.out.println("Column 1: " + column1);
System.out.println("Column 2: " + column2);
}
csvParser.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
The above code will read data from the CSV file called "Data.csv", and print out the first and second columns of each line.
2. Export data:
To export the data in the Java application as a CSV file, you can use the Apache Commons CSV library according to the following steps:
First, add the dependency item of the Apache Commons CSV library to the pom.xml file of the project (if it has not been added).
Next, use the following code example to output the data to the CSV file:
import org.apache.commons.csv.CSVFormat;
import org.apache.commons.csv.CSVPrinter;
import java.io.FileWriter;
import java.io.IOException;
import java.io.Writer;
import java.util.Arrays;
import java.util.List;
public class CSVExporter {
public static void main(String[] args) {
try {
Writer writer = new FileWriter("output.csv");
CSVPrinter csvPrinter = new CSVPrinter(writer, CSVFormat.DEFAULT);
List<String> row1 = Arrays.asList("Data 1", "Data 2");
List<String> row2 = Arrays.asList("Data 3", "Data 4");
csvPrinter.printRecord(row1);
csvPrinter.printRecord(row2);
csvPrinter.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
The above code creates a CSV file called "OUTPUT.CSV" and writes two lines of data into it.
The above is the basic steps and sample code using Apache Commons CSV to implement data.The library provides many other functions that can be thoroughly learned and applied according to specific needs.
