优化代码结构，提供NVR录像检索接口

src/main/java/com/genersoft/iot/vmp/gb28181/utils/DateUtil.java

@@ -0,0 +1,40 @@
+package com.genersoft.iot.vmp.gb28181.utils;
+
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.util.Locale;
+
+/**    
+ * @Description:时间工具类，主要处理ISO 8601格式转换
+ * @author: songww
+ * @date:   2020年5月8日 下午3:24:42     
+ */
+public class DateUtil {
+
+	private static final String yyyy_MM_dd_T_HH_mm_ss_SSSXXX = "yyyy-MM-dd'T'HH:mm:ss.SSSXXX";
+    private static final String yyyy_MM_dd_HH_mm_ss = "yyyy-MM-dd HH:mm:ss";
+    
+	public static String yyyy_MM_dd_HH_mm_ssToISO8601(String formatTime) {
+
+        SimpleDateFormat oldsdf = new SimpleDateFormat(yyyy_MM_dd_HH_mm_ss, Locale.getDefault());
+        SimpleDateFormat newsdf = new SimpleDateFormat(yyyy_MM_dd_T_HH_mm_ss_SSSXXX, Locale.getDefault());
+        try {
+            return newsdf.format(oldsdf.parse(formatTime));
+        } catch (ParseException e) {
+            e.printStackTrace();
+        }
+        return "";
+    }
+	
+	public static String ISO8601Toyyyy_MM_dd_HH_mm_ss(String formatTime) {
+
+        SimpleDateFormat oldsdf = new SimpleDateFormat(yyyy_MM_dd_T_HH_mm_ss_SSSXXX, Locale.getDefault());
+        SimpleDateFormat newsdf = new SimpleDateFormat(yyyy_MM_dd_HH_mm_ss, Locale.getDefault());
+        try {
+            return newsdf.format(oldsdf.parse(formatTime));
+        } catch (ParseException e) {
+            e.printStackTrace();
+        }
+        return "";
+    }
+}