package iterator;
 
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.AbstractList;
 
public class FileLineList extends AbstractList<String> {
	protected BufferedReader reader;
	private File f; 
 
	public FileLineList(String filePath) throws FileNotFoundException {
		f = new File(filePath);
		if (!f.canRead()) {
			throw new FileNotFoundException("Файл '" + f.getAbsolutePath() + "' - не найден!");
		}
	}
 
	@Override
	public String get(int index) {
		try {
			Init();
			String line;
			int count = 0;
			while ((line = reader.readLine()) != null) {
				if (index == count++) {
					return line;
				}
			}
			reader.close();
		} catch (IOException e) {
			WriteReadingError();
		}
		return null;
	}
 
	@Override
	public int size() {
		int count = 0;
		try {
			Init();
			while (reader.readLine() != null) count++;
			reader.close();
		} catch (IOException e) {
			WriteReadingError();
		}
		return count;
	}
 
	protected void Init() throws IOException {
		reader = new BufferedReader(
				new InputStreamReader(
						new FileInputStream(f)
					)
				);
	}
 
	protected void WriteReadingError() {
		System.out.println("Ошибка чтения файла: " + f.getAbsolutePath() + "!");
	}
}