从.txt文档逐行读入数据，用到FileReader和BufferedReader类：

import java.io.IOException;import java.io.FileNotFoundException;import java.io.FileReader;import java.io.BufferedReader;public class ReadLine_Test {	public static void main(String[] args) throws IOException{		String FilePath = "e:/data.txt";		FileReader fr = new FileReader(FilePath); //建立FileReader对象，并实例化为fr		BufferedReader br = new BufferedReader(fr); //建立BufferedReader对象，并实例化为br		StringBuffer sBuffer = new StringBuffer();		String Line = br.readLine();   //从文本中读取一行字符串				int i = 1;		while(Line != null){			System.out.println("Line"+i+":"+Line);			sBuffer.append(Line);			sBuffer.append("\n");			Line = br.readLine();   //从文本中继续读取一行字符串			i = i+1;		}				if(br != null){			br.close();   //关闭BufferedReader对象		}		if(fr != null){			fr.close();   //关闭文件		}	}}