在java中如何在.txt文件中选取一个键及其相应值

import java.io.FileInputStream;
import java.io.IOException;
import java.util.Properties;

public class ReadPropertiesFile {
    public static void main(String[] args) {
        Properties properties = new Properties();
        try {
            FileInputStream fileInputStream = new FileInputStream("file.txt");
            properties.load(fileInputStream);
            fileInputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }

        String key = "yourKey";
        String value = properties.getProperty(key);
        System.out.println("Value for key " + key + ": " + value);
    }
}