addlinenumber.java

JAVA的一些基础教程

import java.io.*;

public class AddLineNumber{
public static void main(String arg[]) throws Exception{
	BufferedReader br = new BufferedReader(new FileReader(arg[0]+".java"));
	PrintStream ps = new PrintStream(new FileOutputStream(arg[0] + ".txt"));
	String line;
	int num = 0;
	while((line = br.readLine()) != null){
		num ++;
		ps.println(num + ": " + line);
	}
	
	ps.close();
	br.close();
}
}