输入输出

package com.lovo.twoday;

import java.io.FileNotFoundException;

import java.io.FileReader;

import java.io.FileWriter;

import java.io.IOException;

import java.io.Reader;

import java.io.Writer;

import javax.swing.JOptionPane;

public class IOsystem {

 public static void main(String[] args) {  

 // TODO Auto-generated method stub  

 Reader r = null;  

  try {    String result = "";  

  r = new FileReader("data.txt");    

   char[] c = new char[10];  

  int length = 0;  

  while((length = r.read(c)) != -1){  

   String str = new String(c, 0, length);  

   result += str;  

  }  

  if((length = r.read(c)) == -1){

    String st =  "从前有座山，山里有座庙，庙里有个老和尚在讲故事。讲的什么呢？";     result = result + st;  

  }   

 System.out.println(result);    

  } catch (FileNotFoundException e) {  

  // TODO Auto-generated catch block  

  e.printStackTrace();

  } catch (IOException e) {

   // TODO Auto-generated catch block  

  e.printStackTrace();   

}finally{

   if(r != null){  

   try {    

  r.close();    

 } catch (IOException e) {  

    // TODO Auto-generated catch block     

 e.printStackTrace();    

 }  

  }

  }

 }

}