java.util.NoSuchElementException: No value present报错解决

2019-10-10 20:33:37.408  INFO 6033 --- [  XNIO-1 task-1] c.l.q.w.rest.errors.ExceptionTranslator  : Exception in controller encountered

'java.util.NoSuchElementException: No value present'


	at java.util.Optional.get(Optional.java:135)
	at com.lenovo.quotation.service.QuoteLineService.modifyGuidanceAndContractEndDateAfterChangeCP(QuoteLineService.java:1280)
	at com.lenovo.quotation.service.QuoteLineService$$FastClassBySpringCGLIB$$d51f02ce.invoke(<generated>)
	at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218)
	at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:749)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
	at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:295)

解决方法

当通过jpa通过id查询时，使用 findById(id).get()，当id对应的主键ID为空时，会报错如上

当id对应的主键ID为空时,如下

classroom（one）-> student（many）

student表中，classroom_id为空时会导致报错：java.util.NoSuchElementException: No value present

详细讲解

https://blog.csdn.net/fly_as_tadpole/article/details/84786840