grails - 如何知道验证错误的原因

Question

如果保存由于某种原因失败，则以下代码将引发grails.validation.ValidationException。但是结果是一个通用错误。如何知道错误的实际原因，以便将其报告给用户？

 def addChild(cName,Parent theParent) {
    println "add child: ${cName}"
    def theChild = new Child(name:cName,parent:theParent)
    theChild.save(failOnError:true)
    return theChild
}

这是返回的堆栈跟踪。我碰巧知道这是由于违反了唯一的约束所导致的，因为我是故意造成的，但是在痕迹中没有任何东西可以表明这是原因与其他约束的违反。

org.codehaus.groovy.runtime.InvokerInvocationException: grails.validation.ValidationException: Validation Error(s) Occurred During Save

    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)

    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)

    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)

    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)

    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

    at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:646)

    at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:436)

    at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:374)

    at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:302)

    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)

    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)

    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)

    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)

    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)

    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)

    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)

    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)

    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)

    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)

    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)

    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849)

    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)

    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454)

    at java.lang.Thread.run(Thread.java:619)

Caused by: grails.validation.ValidationException: Validation Error(s) Occurred During Save

    at AddRecordsService.addChild(AddRecordsService.groovy:30)

    at AddRecordsService$addChild.callCurrent(Unknown Source)

    at AddRecordsService.addAll(AddRecordsService.groovy:11)

    at AddRecordsService$$FastClassByCGLIB$$e47d68f4.invoke(<generated>)

    at net.sf.cglib.proxy.MethodProxy.invoke(MethodProxy.java:149)

    at AddRecordsService$$EnhancerByCGLIB$$cdfdcc61.addAll(<generated>)

    at AddRecordsService$addAll.call(Unknown Source)

    at AddrecordController$_closure2.doCall(AddrecordController.groovy:14)

    at AddrecordController$_closure2.doCall(AddrecordController.groovy)

    ... 32 more

更新

好吧，看来至少到目前为止，使事务回滚并找出导致错误的唯一方法是检查保存是否失败，获取failedobject.errors并抛出RuntimeException。但是现在您如何将错误传递回调用 Controller ？以下无效。

   def addChild(cName,Parent theParent) {
        println "add child: ${cName}"
        def theChild = new Child(name:cName,parent:theParent)

       //theChild.save(failOnError:true)
       //theChild.save()


        if(!theChild.save()){
            println theChild.errors
             throw new RuntimeException(theChild.errors)
            //throw new RuntimeException('unable to save child')
        } 


        return theChild
    }

Answer 1

旧问题，但是否有人偶然发现:在服务中，Grails(2.1)习惯用法是调用save()，如果save失败，则抛出ValidationException。

 if (!theChild.save()) {
     throw new ValidationException(theChild.errors)
 } 

您通常不调用 save(failOnError: true)。相反，在您的 Controller 中，您捕获了ValidationException:

try {
    service.addChild(child)
} catch (ValidationException e) {
    errors.allErrors.each {
        // do something with each error code
    }
}

如果您在 Controller 中完成所有工作，则具有相同的想法。在这种情况下，您当然不必抛出异常然后捕获异常，您可以当场处理 child.errors。