java按行读字节 java按行读取文本

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.InputStreamReader;

public class T {
    public static void main(String[] args) throws Exception{
        long startTime=System.currentTimeMillis();   //获取开始时间
        FileInputStream filestream=new FileInputStream("src/jedis/1.txt");
        byte[] b = new byte[3];
        filestream.read(b);
        String ecode="gbk";
        if (b[0] == -17 && b[1] == -69 && b[2] == -65){
            ecode="utf-8";
        }
        InputStreamReader readStream=new InputStreamReader(filestream,ecode);
        BufferedReader reader=new BufferedReader(readStream);
        
        String temp=null;
        int line=0;//行号
        while((temp=reader.readLine())!=null){
            line++;
            System.out.println(line+":"+temp);
        }
        
        long endTime=System.currentTimeMillis(); //获取结束时间
        if(readStream!=null){
            readStream.close();
        }
        if(reader!=null){
            reader.close();
        }
        System.out.println("程序运行时间： "+(endTime-startTime)/1000+"s");
    }
}