错误日志

Question

我的Hibernate对象需要在保存之前手动分配ID。但我忘了分配它，所以这个错误日志出现了：

ERROR errors.GrailsExceptionResolver  - IdentifierGenerationException occurred when processing request: [POST] /hrims/hapum/maintenance/department/save
Stacktrace follows:
Message: ids for this class must be manually assigned before calling save(): ph.gov.nhmfc.hapum.Department
    Line | Method
->>   24 | save             in ph.gov.nhmfc.DomainService$$EQDMPY5t
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|    191 | save             in ph.gov.nhmfc.hapum.DepartmentService$$EQDM563D
|     85 | save . . . . . . in ph.gov.nhmfc.hapum.maintenance.DepartmentController
|    198 | doFilter         in grails.plugin.cache.web.filter.PageFragmentCachingFilter
|     63 | doFilter . . . . in grails.plugin.cache.web.filter.AbstractFilter
|    449 | executeChain     in org.apache.shiro.web.servlet.AbstractShiroFilter
|    365 | call . . . . . . in org.apache.shiro.web.servlet.AbstractShiroFilter$1
|     90 | doCall           in org.apache.shiro.subject.support.SubjectCallable
|     83 | call . . . . . . in     ''
|    383 | execute          in org.apache.shiro.subject.support.DelegatingSubject
|    362 | doFilterInternal in org.apache.shiro.web.servlet.AbstractShiroFilter
|    125 | doFilter         in org.apache.shiro.web.servlet.OncePerRequestFilter
|   1145 | runWorker . . .  in java.util.concurrent.ThreadPoolExecutor
|    615 | run              in java.util.concurrent.ThreadPoolExecutor$Worker
^    744 | run . . . . . .  in java.lang.Thread

这就是为什么我试图抓住IdentifierGenerationException：

try {
    hibernate.save(insert: true)
}
catch(IdentifierGenerationException e) {
    errors.push("An identifier should be assigned for this record before saving.")
}
catch(Exception e) {
    println(e.getClass())
    errors.push("An error has occured.")
}

令我惊讶的是，它没有进入第一个catch声明，而是转到第二个并打印出来：

class org.springframework.orm.hibernate4.HibernateSystemException

是什么给出的？可以安全地假设IdentifierGenerationException将处理所有HibernateSystemException。如果在Exception下有＆＃34;分类＆＃34; 的其他HibernateSystemException怎么办？

现在我的try-catch声明如下：

try {
    hibernate.save(insert: true)
}
catch(IdentifierGenerationException e) {
    errors.push("An identifier should be assigned for this record before saving.")
}
catch(HibernateSystemException e) {
    errors.push("An identifier should be assigned for this record before saving.")
}
catch(Exception e) {
    errors.push("An unidentifieable error has occured.")
}

我在Grails 2.4.4上使用Hibernate 4。

Answer 1

在您的情况下，似乎IdentifierGenerationException是HibernateSystemException的嵌套例外。因此，如果您只想捕获没有id的对象，则不应尝试捕获HibernateSystemException，因为HibernateSystemException也可能由IdentifierGenerationException以外的其他原因引起。

您应该检查异常的原因，然后检查嵌套异常是否为IdentifierGenerationException的实例。或者检查对象id是否为null。