in.data中的数据"28.7812 34.4632 31.3381 31.2834..."

File fileIn=new File("in.data");
  //File fileOut=new File("out.data");
  if(fileIn.exists()){
          System.out.println("the file's path:"+fileIn.getPath());
          System.out.println("the directory is "+fileIn.getParent());
  }
  else
          System.out.println("no file");
  
  FileReader fr=new FileReader(fileIn);
  StreamTokenizer stk=new StreamTokenizer(fr);
  
  if(stk.nextToken()==StreamTokenizer.TT_NUMBER){
           System.out.println("yes a number");
           System.out.println("value is "+stk.nval);
  }

即可读入数据。nextToken原来只是返回该token的类型。

In DataInputStream  the readDouble() 好像只是对用DataOutputStream 的 writeDouble()写入的数据读出有用？写入是用unicode编码的么