Can't load a csv file using CSVLoader

While using weka csv loader it gives me error in setSource Function " cannot resolve setSource

import weka.core.Instances;
import weka.core.converters.CSVLoader;
import java.io.File;
@SpringBootApplication
public class Demo3Application {

    public static void main(String[] args) {
        SpringApplication.run(Demo3Application.class, args);
    }


    // Load CSV file
    CSVLoader loader = new CSVLoader();
    loader.setSource(new File("C:\\Users\\user\\IdeaProjects\\demo3\\testdata3.csv.csv"));
    Instances data = loader.getDataSet();
}

In Java, any task/operation which is to be performed should be inside a function.

Below is the updated code.

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import weka.core.Instances;
import weka.core.converters.CSVLoader;

import java.io.File;
import java.io.IOException;

@SpringBootApplication
public class Demo3Application {

    public static void main(String[] args) throws IOException {
        SpringApplication.run(Demo3Application.class, args);
        CSVLoader loader = new CSVLoader();
        loader.setSource(new File("C:\\Users\\Caroline.Karam\\IdeaProjects\\demo3\\testdata3.csv.csv"));
        Instances data = loader.getDataSet();
    }

}