编写一个程序， 将 a.txt 文件中的单词与 b.txt 文件中的 单词交替合并到 c.txt 文件中， a.txt 文件中的单词用回车符 分隔， b.txt 文件中用回车或空格进行分隔。

package cn.itcast;  
  
import java.io.File;  
import java.io.FileReader;  
import java.io.FileWriter;  
  
public class MainClass{  
    public static void main(String[] args) throws Exception{  
        FileManager a = new FileManager("a.txt",new char[]{'\n'});  
        FileManager b = new FileManager("b.txt",new char[]{'\n',' '});        
        FileWriter c = new FileWriter("c.txt");  
        String aWord = null;  
        String bWord = null;  
        while((aWord = a.nextWord()) !=null ){  
            c.write(aWord + "\n");  
            bWord = b.nextWord();  
            if(bWord != null)  
                c.write(bWord + "\n");  
        }  
          
        while((bWord = b.nextWord()) != null){  
            c.write(bWord + "\n");  
        }     
        c.close();  
    }  
      
}  
  
  
class FileManager{  
  
    String[] words = null;  
    int pos = 0;  
    public FileManager(String filename,char[] seperators) throws Exception{  
        File f = new File(filename);  
        FileReader reader = new FileReader(f);  
        char[] buf = new char[(int)f.length()];  
        int len = reader.read(buf);  
        String results = new String(buf,0,len);  
        String regex = null;  
        if(seperators.length >1 ){  
            regex = "" + seperators[0] + "|" + seperators[1];  
        }else{  
            regex = "" + seperators[0];  
        }  
        words = results.split(regex);  
    }  
      
    public String nextWord(){  
        if(pos == words.length)  
            return null;  
        return words[pos++];  
    }  
  
}