增加对Subscribe（订阅）方法的支持

src/main/java/com/genersoft/iot/vmp/gb28181/transmit/cmd/SIPRequestHeaderProvider.java

@@ -164,4 +164,51 @@ public class SIPRequestHeaderProvider {
 		request.setContent(content, contentTypeHeader);
 		return request;
 	}
+
+	public Request createSubscribeRequest(Device device, String content, String viaTag, String fromTag, String toTag, Integer expires, String event) throws ParseException, InvalidArgumentException, PeerUnavailableException {
+		Request request = null;
+		// sipuri
+		SipURI requestURI = sipFactory.createAddressFactory().createSipURI(device.getDeviceId(), device.getHostAddress());
+		// via
+		ArrayList<ViaHeader> viaHeaders = new ArrayList<ViaHeader>();
+		ViaHeader viaHeader = sipFactory.createHeaderFactory().createViaHeader(sipConfig.getSipIp(), sipConfig.getSipPort(),
+				device.getTransport(), viaTag);
+		viaHeader.setRPort();
+		viaHeaders.add(viaHeader);
+		// from
+		SipURI fromSipURI = sipFactory.createAddressFactory().createSipURI(sipConfig.getSipId(),
+				sipConfig.getSipIp() + ":" + sipConfig.getSipPort());
+		Address fromAddress = sipFactory.createAddressFactory().createAddress(fromSipURI);
+		FromHeader fromHeader = sipFactory.createHeaderFactory().createFromHeader(fromAddress, fromTag);
+		// to
+		SipURI toSipURI = sipFactory.createAddressFactory().createSipURI(device.getDeviceId(), sipConfig.getSipDomain());
+		Address toAddress = sipFactory.createAddressFactory().createAddress(toSipURI);
+		ToHeader toHeader = sipFactory.createHeaderFactory().createToHeader(toAddress, toTag);
+		// callid
+		CallIdHeader callIdHeader = device.getTransport().equals("TCP") ? tcpSipProvider.getNewCallId()
+				: udpSipProvider.getNewCallId();
+		// Forwards
+		MaxForwardsHeader maxForwards = sipFactory.createHeaderFactory().createMaxForwardsHeader(70);
+		// ceq
+		CSeqHeader cSeqHeader = sipFactory.createHeaderFactory().createCSeqHeader(1L, Request.SUBSCRIBE);
+
+		request = sipFactory.createMessageFactory().createRequest(requestURI, Request.SUBSCRIBE, callIdHeader, cSeqHeader, fromHeader,
+				toHeader, viaHeaders, maxForwards);
+
+		
+		Address concatAddress = sipFactory.createAddressFactory().createAddress(sipFactory.createAddressFactory().createSipURI(sipConfig.getSipId(), sipConfig.getSipIp()+":"+sipConfig.getSipPort()));
+		request.addHeader(sipFactory.createHeaderFactory().createContactHeader(concatAddress));
+
+		// Expires
+		ExpiresHeader expireHeader = sipFactory.createHeaderFactory().createExpiresHeader(expires);
+		request.addHeader(expireHeader);
+
+		// Event
+		EventHeader eventHeader = sipFactory.createHeaderFactory().createEventHeader(event);
+		request.addHeader(eventHeader);
+
+		ContentTypeHeader contentTypeHeader = sipFactory.createHeaderFactory().createContentTypeHeader("APPLICATION", "MANSCDP+xml");
+		request.setContent(content, contentTypeHeader);
+		return request;
+	}
 }