【fingBugs】可能空指针的间接引用，造成NullPointerException

Possible null pointer dereference
There is a branch of statement that, if executed, guarantees that a null value will be dereferenced, which would generate a NullPointerException when the code is executed. Of course, the problem might be that the branch or statement is infeasible and that the null pointer exception can’t ever be executed; deciding that is beyond the ability of FindBugs.

解释：可能空指针的间接引用，这段代码，如果要执行，要保证非null值，否则将在执行代码时生成NullPointerException。当然，问题可能是分支或语句不可行，并且不能执行空指针异常;

代码：

 Page pageList = entityService.selectPage(pager,conditon);
 //以下没有检查非null，就直接使用pageList引用，如果pageList是null
 //下面代码在运行时报错NullPointerException
 int totalNumber = pageList.getTotal();