我試圖使用ByteBuffer來解析我接收到的數據包作爲字節數組,並可能包含部分或多個數據包。數據包的長度是可變的,所以我需要解析前兩個字節來獲取數據包的長度,並且似乎一旦我翻轉()緩衝區來讀取數據包,如果數據包不完整,我不能返回並追加更多的數據。java bytebuffer write read append
如何將數據寫入緩衝區,讀取其中的一些內容以驗證內容,然後在保留讀取數據的同時向其附加更多數據?
class Foo {
static final byte[] DATA1 = {0, 13, 2, 65, 88, 80, 55, 51, 52, 84, 82, 43, -111};
static final byte[] DATA2 = {0, 21, 6, 2, 3, 67, 23, 71, -77, 24, -66, -12, -76, 98, 25, 61, 54, -20, 127, -118, 71};
static final byte[] DATA3 = {0, 21, 5, 3, 5, 67};
static final byte[] DATA4 = {23, 72, -50, 24, -66, -9, -31, -86, 25, 61, -95, 75, 71, 47, -102, 0, 13, 2, 84};
static final byte[] DATA5 = {82, 65, 28, 10, 65, 71, 52, 44, 11};
ByteBuffer mByteBuffer = ByteBuffer.allocate(4096);
public void test() {
mByteBuffer.order(ByteOrder.BIG_ENDIAN);
parse(DATA1);
parse(DATA2);
parse(DATA3);
parse(DATA4);
parse(DATA5);
}
public void parse(byte[] bytes) {
short byteCount;
short crc;
mByteBuffer.put(bytes);
mByteBuffer.flip();
while (mByteBuffer.remaining() > 5) {
byteCount = mByteBuffer.getShort();
// check for invalid buffer
if (byteCount < 5) {
mByteBuffer.clear();
return;
}
if (mByteBuffer.remaining() < (byteCount - 2)) {
// TODO: incomplete packet, do something
}
// payload (u8[1 .. 4092])
byte[] payload = new byte[byteCount - 4];
mByteBuffer.get(payload, 0, payload.length);
// crc (u16)
crc = mByteBuffer.getShort();
}
mByteBuffer.clear();
}
}
不會'compact()'刪除我已經讀過的任何數據,比如我正在偷看的字節數,看看我是否有一個完整的數據包? – jmfox24