Question

很多时候我得到像这样的堆栈跟踪（请参阅箭头中的混淆线）：

org.springframework.dao.DataIntegrityViolationException: could not execute statement; SQL [n/a]; constraint [PRIMARY]; nested exception is org.hibernate.exception.ConstraintViolationException: could not execute statement
                at org.springframework.orm.hibernate5.SessionFactoryUtils.convertHibernateAccessException(SessionFactoryUtils.java:164)
                at org.springframework.orm.hibernate5.HibernateTransactionManager.convertHibernateAccessException(HibernateTransactionManager.java:741)
                at org.springframework.orm.hibernate5.HibernateTransactionManager.doCommit(HibernateTransactionManager.java:589)
                at org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:761)
                at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:730)
                at org.springframework.transaction.interceptor.TransactionAspectSupport.commitTransactionAfterReturning(TransactionAspectSupport.java:485)
                at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:291)
                at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
                at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
                at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:653)
--------->      at com.panpwr.admin.services.detector.SimpleDetectorPersistenceService$$EnhancerBySpringCGLIB$$66303639.saveComplexRuleAndActionTemplates(<generated>)
                at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
                at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
                at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
...
...
...

$$标志是什么，以及＆＃39;生成的是什么？意味着在这一行？ com.panpwr.admin.services.detector.SimpleDetectorPersistenceService$$EnhancerBySpringCGLIB$$66303639.saveComplexRuleAndActionTemplates(<generated>)

为什么它只说执行的方法而不是它中的行呢？

Answer 1

$是类名中允许的字符。

名称SimpleDetectorPersistenceService$$EnhancerBySpringCGLIB$$66303639暗示它是一个由Spring框架在运行时使用CGLIB动态生成的类。

他们使用$$和数字偏移量使此类名称唯一，以避免与现有类冲突。

stracktrace中的字符串(<generated>)也是由CGLIB生成的：
当CGLIB在运行时创建一个类时，它使用<generated>作为源文件名的占位符。然后，堆栈跟踪只是打印此字符串而不是真实的源文件和行号。

$$和<generated>在java stacktrace中意味着什么？

1 个答案: