The reason for the error reported by android studio is: Bad offset/length: offset=0 len=0 in.length=0

1. The error message is as follows

E/CustomActivityOnCrash: App has crashed, executing CustomActivityOnCrash's UncaughtExceptionHandler
    java.lang.NumberFormatException: Bad offset/length: offset=0 len=0 in.length=0

2. This kind of error occurs, a large part of the reason is that the object is an empty string.
I execute this line of code

 return String.valueOf(new BigDecimal(dou).intValue());

I printed the log and found that the value of dou is an empty string. So it will report an error
, just assign a value to dou.