增加设备删除接口，只允许删除离线设备；增加视频停止播放接口

src/main/java/com/genersoft/iot/vmp/gb28181/session/SsrcUtil.java

@@ -0,0 +1,91 @@
+package com.genersoft.iot.vmp.gb28181.session;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Random;
+
+import com.genersoft.iot.vmp.conf.SipConfig;
+import com.genersoft.iot.vmp.utils.SpringBeanFactory;
+
+/**
+ * @Description:SIP信令中的SSRC工具类。SSRC值由10位十进制整数组成的字符串，第一位为0代表实况，为1则代表回放；第二位至第六位由监控域ID的第4位到第8位组成；最后4位为不重复的4个整数
+ * @author: songww
+ * @date: 2020年5月10日 上午11:57:57
+ */
+public class SsrcUtil {
+
+	private static String ssrcPrefix;
+
+	private static List<String> isUsed;
+
+	private static List<String> notUsed;
+
+	private static void init() {
+		SipConfig sipConfig = (SipConfig) SpringBeanFactory.getBean("sipConfig");
+		ssrcPrefix = sipConfig.getSipDomain().substring(4, 9);
+		isUsed = new ArrayList<String>();
+		notUsed = new ArrayList<String>();
+		for (int i = 1; i < 10000; i++) {
+			if (i < 10) {
+				notUsed.add("000" + i);
+			} else if (i < 100) {
+				notUsed.add("00" + i);
+			} else if (i < 1000) {
+				notUsed.add("0" + i);
+			} else {
+				notUsed.add(String.valueOf(i));
+			}
+		}
+	}
+
+	/**
+	 * 获取视频预览的SSRC值,第一位固定为0
+	 * 
+	 */
+	public static String getPlaySsrc() {
+		return "0" + getSsrcPrefix() + getSN();
+	}
+
+	/**
+	 * 获取录像回放的SSRC值,第一位固定为1
+	 * 
+	 */
+	public static String getPlayBackSsrc() {
+		return "1" + getSsrcPrefix() + getSN();
+	}
+
+	/**
+	 * 释放ssrc，主要用完的ssrc一定要释放，否则会耗尽
+	 * 
+	 */
+	public static void releaseSsrc(String ssrc) {
+		String sn = ssrc.substring(6);
+		isUsed.remove(sn);
+		notUsed.add(sn);
+	}
+
+	/**
+	 * 获取后四位数SN,随机数
+	 * 
+	 */
+	private static String getSN() {
+		String sn = null;
+		if (notUsed.size() == 0) {
+			throw new RuntimeException("ssrc已经用完");
+		} else if (notUsed.size() == 1) {
+			sn = notUsed.get(0);
+		} else {
+			sn = notUsed.get(new Random().nextInt(notUsed.size() - 1));
+		}
+		notUsed.remove(0);
+		isUsed.add(sn);
+		return sn;
+	}
+
+	private static String getSsrcPrefix() {
+		if (ssrcPrefix == null) {
+			init();
+		}
+		return ssrcPrefix;
+	}
+}

src/main/java/com/genersoft/iot/vmp/gb28181/session/VideoStreamSessionManager.java

@@ -0,0 +1,41 @@
+package com.genersoft.iot.vmp.gb28181.session;
+
+import java.util.concurrent.ConcurrentHashMap;
+
+import javax.sip.ClientTransaction;
+
+import org.springframework.stereotype.Component;
+
+/**    
+ * @Description:视频流session管理器，管理视频预览、预览回放的通信句柄 
+ * @author: songww
+ * @date:   2020年5月13日 下午4:03:02     
+ */
+@Component
+public class VideoStreamSessionManager {
+
+	private ConcurrentHashMap<String, ClientTransaction> sessionMap = new ConcurrentHashMap<>();
+
+	public String createPlaySsrc(){
+		String ssrc = SsrcUtil.getPlaySsrc();
+		return ssrc;
+	}
+	
+	public String createPlayBackSsrc(){
+		String ssrc = SsrcUtil.getPlayBackSsrc();
+		return ssrc;
+	}
+	
+	public void put(String ssrc,ClientTransaction transaction){
+		sessionMap.put(ssrc, transaction);
+	}
+	
+	public ClientTransaction get(String ssrc){
+		return sessionMap.get(ssrc);
+	}
+	
+	public void remove(String ssrc) {
+		sessionMap.remove(ssrc);
+		SsrcUtil.releaseSsrc(ssrc);
+	}
+}