java文件输入和输出

1.输入

读取文件:

import java.io.*;

import java.math.*;

import java.util.*;

public class Main

{

public static void main(String args[]) throws Exception

{

Scanner cin=new Scanner((new FileInputStream("D:\\in.txt")));

int a,b;

while(cin.hasNext())

{

a=cin.nextInt();

b=cin.nextInt();

System.out.println(a+b);

}

}

}

如此简单方便~

输出文件
import java.io.*;

import java.math.*;

import java.util.*;

public class Main

{

public static void main(String args[]) throws Exception

{

Scanner cin=new Scanner(new FileInputStream("D:\\in.txt"));

File F=new File("D:\\out.txt");

BufferedWriter cout=new BufferedWriter(new FileWriter(F));

while(cin.hasNext())

{

int a=cin.nextInt();

int b=cin.nextInt();

cout.append(Integer.toString(a+b));

cout.newLine();

}

cout.close();

}

}