把数字写到文件中出错
import   java.io.*;   
 public   class   Test 
 { 
 public   static   void   main(String[]   args)   throws   Exception 
 { 
       byte[]   a   =   new   byte[10]; 
       for(byte   i   =   0;   i    <   10;   i++) 
          a[i]   =   i; 
       File   f   =   new   File( "file.txt "); 
       FileWriter   fw   =   new   FileWriter(f); 
       fw.write(new   String(a)); 
       fw.close();         
       FileReader   fr   =   new   FileReader(f); 
       char[]   b   =   new   char[1024]; 
       int   len   =   fr.read(b); 
       System.out.println(new   String(b,0,len)); 
 } 
 }   
 我想把0~9这九个数写到文件中,为什么不行呢? 
------解决方案--------------------那是字节,不是字符. 
 a[i]=(byte)( '0 '+i); 
 看看.
------解决方案--------------------楼上正解!
------解决方案--------------------import java.io.*;   
 public class Test 
 { 
 public static void main(String[] args) throws Exception 
 { 
 char[] a = new byte[10]; 
 for(char i =  '0 '; i  <  '0’+10; i++) 
 a[i] = i; 
 File f = new File( "file.txt "); 
 FileWriter fw = new FileWriter(f); 
 fw.write(a); 
 fw.close();   
 FileReader fr = new FileReader(f); 
 char[] b = new char[1024]; 
 int len = fr.read(b); 
 System.out.println(new String(b,0,len)); 
 } 
 }