IO流实例代码练习

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

public class FileText {

	
	public static void main(String[] args) {
		int b=0;
		FileInputStream in= null;
		FileOutputStream out=null;
		try{ 
			in=new FileInputStream("d:/a.txt");
			out=new FileOutputStream("d:/b.txt");
			try {
				while((b=in.read())!=-1){   
				out.write(b);}
			} catch (IOException e) {
				
			     System.out.println("文件复制异常!");
			     System.exit(-1);}
		       
		    }catch(FileNotFoundException e){
				 System.out.println("系统找不到指定文件！");
				 System.exit(-1);
				}
		      
		  
		System.out.println("复制成功！！");}	
}