Tag Archives: java.lang.NullPointerException: cannot unbox null value

java.lang.nullpointerexception: cannot unbox null value [How to Solve]

Solution: first, locate the key sentence according to the error report

list<charginPileVO>......

Then the breakpoint and add this sentence to watch will show a real exception: Java.Lang.nullpointerexception: cannot unbox null value
because the object is empty when unpacking, an error is reported when unpacking. The basic type from integer object to int will be unpacked automatically. And integer is empty, so an error is reported