编写IoDemo.java的Java应用程序，程序完成的功能是：首先读取text.txt文件内容，再通过键盘输入文件的名称为iodemo.txt,把text.txt的内容存入iodemo.txt

package lianxi;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.util.Scanner;

public class GaimingDemo {

public static void main(String[] args)
{
try
{
FileInputStream in = new FileInputStream("d:/text.txt") ;

byte[ ]  b = new byte[1024] ;

String s = "" ;

int i = -1 ;

while((i=in.read(b))>0)
{
s += new String(b,0,i) ;
}

System.out.println("输入完成！");

System.out.println("读取到的内容为："+s);

in.close();

System.out.println("请输入修改后的名字：");

Scanner sc = new Scanner(System.in) ;

String str = sc.nextLine( ) ;

File file = new File("d:/text.txt");

file.renameTo(new File("d:/"+str)) ;

FileOutputStream out = new FileOutputStream(file) ;

byte[ ] by = str.getBytes() ;

out.write(by);

out.close();

System.out.println("输出完成！");

System.out.println("改名成功！");

}
catch (Exception e)
{
e.printStackTrace();
}
}

}