A. Buffer clear():清除缓冲区,将position设置为0,limit设置为capacity Buffer flip():反转缓冲区,先将limit设置为当前position位置,然后再将position设置为0 C. Buffer mark():获取Buffer的标记(mark), D. Buffer rewind():倒带缓冲区,将position设置为0,并取消设置的标记
A. read() B. write() C. close() D. available()