java.lang.NumberFormatException: empty String

空值轉換問題

java.lang.NumberFormatException: empty String
	at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1842)
	at sun.misc.FloatingDecimal.parseDouble(FloatingDecimal.java:110)
	at java.lang.Double.parseDouble(Double.java:538)
	at AddDBSensorLog.main(AddDBSensorLog.java:131)

解決方法