Untitled

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class Exception {
    public static void main(String[] args) {
        Container container;
        Checker checker = new Checker();
        
        try {
            container = Container.fromFile("file.txt");
            checker.checkDelimiter(container, ",");
        } catch (FileNotFoundException | DelimiterException e) {
            System.err.println(e.getMessage());
        }
    }

    public static class Container {
        private final List<String> lines = new ArrayList<>();
        
        public static Container fromFile(String filePath) {
            try (BufferedReader br = new BufferedReader(new FileReader(filePath))) {
                Container container = new Container();
                String line;
                while ((line = br.readLine()) != null) {
                    container.lines.add(line);
                }
                return container;
            } catch (IOException e) {
                throw new FileNotFoundException("Error reading file: " + e.getMessage(), e);
            }
        }
        
        public int getLineCount() {
            return lines.size();
        }
        
        public String getLine(int index) {
            return lines.get(index);
        }
    }

    public static class Checker extends RuntimeException {
        private void checkDelimiter(Container container, String delimiter) {
            for (int i = 0; i < container.getLineCount(); i++) {
                var line = container.getLine(i);
                if (!line.endsWith(delimiter)) {
                    throw new DelimiterException("Line does not end with delimiter: " + line);
                }
            }
        }
    }

    public static class FileNotFoundException extends RuntimeException {
        public FileNotFoundException(String message, Throwable cause) {
            super(message, cause);
        }
    }

    public static class DelimiterException extends RuntimeException {
        public DelimiterException(String message) {
            super(message);
        }
    }
}