Why some stacktrace do not have line number in java

Question

I have a bug from my customer and when I look into the log we trace the exception, some of the stacktrace do not have line number:

at xxxx.xxx.xx.x.xx.DayIntervalRule.getInterval(DayIntervalRule.java)
at xxxx.xxx.xx.x.xx.XXSchedule.getNextDueDate(XXSchedule.java)
at xxxx.xxx.xx.x.xx.XXSchedule.evaluateRules(XXSchedule.java)

Please note that: I have replace the package name into something like"xx"),and all of the class and method are defined in our application:

The full stack trace are as below:

java.lang.NullPointerException
    at xxxx.xxx.xx.x.xx.DayIntervalRule.getInterval(DayIntervalRule.java)
    at xxxx.xxx.xx.x.xx.XXSchedule.getNextDueDate(XXSchedule.java)
    at xxxx.xxx.xx.x.xx.XXSchedule.evaluateRules(XXSchedule.java)
    at xxxx.xxx.xx.x.xx.EvaluateRulesVistor.visitXXNode(EvaluateRulesVistor.java:56)
    at xxxx.xxx.xx.x.xx.XXNode.accept(XXNode.java:396)
    at xxxx.xxx.xx.x.xx.AssetXX.traverseForest(AssetXX.java:351)
    at xxxx.xxx.xx.x.xx.AssetXX.run(AssetXX.java:70)
    at xxxx.xxx.xx.x.xx.XXEngine.doForecast(XXEngine.java:437)
    at xxxx.xxx.xx.x.xx.XXEngine.forecastWorkOrders2(XXEngine.java:380)

I am interested in why this happens?Is it possible that my customer do something to the existing code(customization)?

Answer 1

The code that does not display line numbers was compiled without debug information.