int bufferSize;
        if (initialCapacity > 0 && initialCapacity <= MAX_BUF_SIZE) {
            bufferSize = initialCapacity;
        } else {
            bufferSize = DEFAULT_BUF_SIZE;
        }
        char[] buf = new char[bufferSize];
        int size = 0;
        int len;
        try {
            while ((len = reader.read(buf, size, bufferSize - size)) != -1) {