FileChannel fileChannel2=new FileInputStream("D:\\abr.txt").getChannel();
Charset charset=Charset.forName("utf-8");
ByteBuffer byteBuffer=ByteBuffer.allocate(BIZE);
while (fileChannel2.read(byteBuffer)!=-1){
    charset.decode(byteBuffer);
byteBuffer.flip();
CharBuffer charBuffer=charset.decode(byteBuffer);
 
System.out.println(charBuffer.toString());
System.out.println("------------");
byteBuffer.clear();
}

1.解碼：從通道中讀取資料儲存在ByteBuffer中，呼叫charset.decode(bytebuffer)進行對應格式的解碼，並得到CharBuffer

2.編碼：和解碼互逆，把呼叫chareset.encode（CharBuffer）,返回出特定編碼後的ByteBuffer，放入通道

3.

Charset charset=Charset.forName("utf-8");