大神帮我看一下这个程序的按位或运算是什么作用

Question

public class VoteMsgBinCoder implements VoteMsgCoder {
public static final int MIN_WIRE_LENGTH = 4;
public static final int MAX_WIRE_LENGTH = 16;
public static final int MAGIC = 0x5400;
public static final int MAGIC_MASK = 0xfc00;
public static final int MAGIC_SHIFT = 8;
public static final int RESPONSE_FLAG = 0x0200;
public static final int INQUIRE_FLAG = 0x0100;
public byte[] toWire(VoteMsg msg) throws IOException {
ByteArrayOutputStream byteStream = new ByteArrayOutputStream();
DataOutputStream out = new DataOutputStream(byteStream); // converts nts

short magicAndFlags = MAGIC;
if (msg.isInquiry()) {
magicAndFlags |= INQUIRE_FLAG;
}
if (msg.isResponse()) {
magicAndFlags |= RESPONSE_FLAG;//知道怎么运算，但是不知道在这个程序里的作用意义
}
out.writeShort(magicAndFlags);
// We know the candidate ID will fit in a short: it's > 0 && < 1000
out.writeShort((short) msg.getCandidateID());
if (msg.isResponse()) {
out.writeLong(msg.getVoteCount());
}
out.flush();
byte[] data = byteStream.toByteArray();
return data;
}

Answer 1

添加那个标记，在判断是否存在时，用&它，就可以知道是否包含那个标记