增加nowDay方法

src/main/java/org/redkale/util/Times.java

@@ -21,6 +21,8 @@ public final class Times {
 
     private static final int ZONE_RAW_OFFSET = TimeZone.getDefault().getRawOffset();
 
+    static final String FORMAT_DAY = "%1$tY-%1$tm-%1$td"; // yyyy-MM-dd
+    
     static final String FORMAT_SECONDS = "%1$tY-%1$tm-%1$td %1$tH:%1$tM:%1$tS"; // yyyy-MM-dd HH:mm:ss
 
     static final String FORMAT_MILLS = "%1$tY-%1$tm-%1$td %1$tH:%1$tM:%1$tS.%1$tL"; // yyyy-MM-dd HH:mm:ss.fff
@@ -47,6 +49,15 @@ public final class Times {
         return String.format(FORMAT_MILLS, System.currentTimeMillis());
     }
 
+    /**
+     * 获取当天2015-01-01格式的string值
+     *
+     * @return 2015-01-01格式的string值
+     */
+    public static String nowDay() {
+        return String.format(FORMAT_DAY, System.currentTimeMillis());
+    }
+
     /**
      * 将指定时间格式化为 yyyy-MM-dd HH:mm:ss
      *