下面哪些代码是正确的
（A）File f = new File("/","java.txt");
（B）DataInputStream d = new DataInputStream(System.in);
（C）OutputStreamWriter o = new OutputStreamWriter(System.out);
（D）RandomAccessFile r = new RandomAccessFile("java.txt");

下面哪些代码是正确的
（A）File f = new File("/","java.txt");
（B）DataInputStream d = new DataInputStream(System.in);
（C）OutputStreamWriter o = new OutputStreamWriter(System.out);
（D）RandomAccessFile r = new RandomAccessFile("java.txt");