The application of the CSV expansion framework in the Java library is real
Application instance of the CSV expansion framework in the Java library
CSV (COMMA SEPARATED VALUES) is a commonly used file format that is used to store and exchange data separated by comma.In Java development, processing CSV files is a common task, and you can use various CSV expansion frameworks to simplify this process.
A commonly used Java library that can be used to handle the read and write operation of CSV files is OpenCSV.It provides a set of simple and easy -to -use APIs that allow developers to quickly read and write CSV files.Below is an application example using the OpenCSV library:
1. First, you need to introduce the OpenCSV library in your project.You can add the following dependencies to the pom.xml file:
<dependency>
<groupId>com.opencsv</groupId>
<artifactId>opencsv</artifactId>
<version>5.5.2</version>
</dependency>
2. Read the CSV file
The following is a sample code, demonstrating how to use the OpenCSV library to read the data from the CSV file and print it out:
import com.opencsv.CSVReader;
import java.io.FileReader;
import java.io.IOException;
public class ReadCSVExample {
public static void main(String[] args) {
try (CSVReader reader = new CSVReader(new FileReader("data.csv"))) {
String[] line;
While ((line = reader.readnext ())! = NULL) {// Read the data ryle
For (string value: line) {// traversed the value of each cell
System.out.print(value + " ");
}
System.out.println();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
In the above example, we use the CSVReader class from a CSV file named "Data.csv" to read data.Each line read is stored in a String array, and we can access the value of each cell by traversing this array.
3. Write into CSV files
The following is a sample code, demonstrating how to use the OpenCSV library to write the data into the CSV file:
import com.opencsv.CSVWriter;
import java.io.FileWriter;
import java.io.IOException;
public class WriteCSVExample {
public static void main(String[] args) {
try (CSVWriter writer = new CSVWriter(new FileWriter("output.csv"))) {
String[] firstLine = {"Name", "Age", "City"};
writer.writenext (firstline); //
String[] secondLine = {"John Doe", "30", "New York"};
writer.writenext (secondline); // Write data
String[] thirdLine = {"Jane Smith", "25", "San Francisco"};
writer.writenext (ThirdLine); // Write the data
} catch (IOException e) {
e.printStackTrace();
}
}
}
In the above example, we used the CSVWriter class to write the data into the CSV file named "Output.csv".Use the Writenext () method to write data one by one, and each data row is a String array.
By using the OpenCSV library, Java developers can easily read and write CSV files without having to manually process the comma separators and rotary characters.This makes CSV file processing simpler and efficient.
