文件读写

package 文件读取;
import java.io.*;
import java.util.*;
public class File {
 public static void main(String[] args)throws Exception
    {
            FileReader file_source=null;
            FileWriter file_destination=null;
            try
            {
                    file_source=new FileReader("D:/a.txt");
                    file_destination=new FileWriter("D:/b.txt");
                    char[] buf=new char[1024];
                    int len=0;
                    while((len=file_source.read(buf))!=-1)
                    {       
//                            Sort(buf);
                            Arrays.sort(buf);
                            System.out.println(buf);
                           
                            file_destination.write(buf,0,len);
                            file_destination.flush();
                    }
            }
            catch(IOException e)
            {
                    e.printStackTrace();
            }
            finally
            {
                    try
                    {
                            if(file_source!=null)
                                    file_source.close();
                    }
                    catch(IOException e)
                    {
                            e.printStackTrace();
                    }
                    try
                    {
                            if(file_destination!=null)
                                    file_destination.close();
                    }
                    catch(IOException e)
                    {
                            e.printStackTrace();
                    }
                   
            }
    }
}