java 按行读取文件

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;

public class LogOutputUtil {

	public static String readFileByLines(String fileName) {
        File file = new File(fileName);
        BufferedReader reader = null;
        String message = "    ";
        try {
            reader = new BufferedReader(new FileReader(file));
            String currentLineString = "";
            while ((currentLineString = reader.readLine()) != null) {
            	if(currentLineString.contains("导入错误！")){
            		message = message + currentLineString.substring(currentLineString.indexOf("导入错误！"))+"\n    ";
            	}    
            }
            reader.close();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (reader != null) {
                try {
                    reader.close();
                } catch (IOException e1) {
                }
            }
        }
        return message;
    }
	
	public static void main(String[] args) {
		String message = readFileByLines("logs/error.log");
		System.out.println(message);
	}
}