問題描述

我正在使用 ColdFusion 8.我想在 ColdFusion 中捕獲 NoClassDefFoundError 異常，但是我不能...它仍然失敗并在 exception.log 文件中記錄錯(cuò)誤.這是我嘗試過的.

I am using ColdFusion 8. I would like to catch a NoClassDefFoundError exception in ColdFusion however I can't... It still fails and logs the error in the exception.log file. Here is what I tried.

<cftry>
    <cfset myJavaObject.myMethod()>
    <cfcatch type="any">
        <cfdump var="#cfcatch #">
    </cfcatch>
    <cfcatch type="java.lang.Throwable">
        Horrible exception.
        <cfdump var="#cfcatch #">
    </cfcatch>
</cftry>

但這不起作用.你能告訴我怎么做嗎?我需要在特定位置捕獲此錯(cuò)誤，而不是在 Application.cfc 的 OnError 函數(shù)中.

But this does not work. Could you please show me how to do that? I need to catch this error at a particular place and not in the OnError function of my Application.cfc.

推薦答案

現(xiàn)在我喝了更多的咖啡，我不認(rèn)為 cfcatch 能夠捕獲 NoClassDefFoundError.根據(jù)文檔，它只處理 Exceptions:

Now that I have had more coffee, I do not think cfcatch is capable of catching a NoClassDefFoundError. According to the documentation, it only processes Exceptions:

異常是破壞正常指令流的事件在 ColdFusion 頁面中，例如數(shù)據(jù)庫操作失敗、丟失包括文件和開發(fā)人員指定的事件.

Exceptions are events that disrupt the normal flow of instructions in a ColdFusion page, such as failed database operations, missing include files, and developer-specified events.

NoClassDefFoundError 是一個(gè) 錯(cuò)誤.

一個(gè)錯(cuò)誤表示嚴(yán)重的問題，一個(gè)合理的應(yīng)用程序不應(yīng)該試圖抓住

An Error indicates serious problems that a reasonable application should not try to catch

聽起來 cfcatch 只是為了處理正常的可恢復(fù)"問題而設(shè)計(jì)的.一旦你得到 NoClassDefFoundError，你真的無能為力.這是一個(gè)嚴(yán)重的錯(cuò)誤，你無法克服它(在正常情況下).您最多只能顯示錯(cuò)誤消息并退出.

It sounds like cfcatch was only designed to handle normal "recoverable" problems. There is really not much you can do once you get a NoClassDefFoundError. It is a severe error and you cannot get past it (under normal circumstances). The most you can do is show an error message and exit.

Application.onErrora> 似乎可以處理 NoClassDefFoundError 等未捕獲的錯(cuò)誤以及異常.所以我認(rèn)為你能做的最好的就是實(shí)現(xiàn) onError 并讓它顯示一個(gè)錯(cuò)誤頁面.

Application.onError seems to handle uncaught Errors like NoClassDefFoundError, as well as Exceptions. So I think the best you can do is implement onError and have it display an error page.

    <!---- test code --->
    <cfset myJavaObject = createObject("java", "path.to.MyClass") />
    <cfset myJavaObject.myMethod() />

    <!---- Application.cfc --->
    <cfcomponent>
         .... settings ...
         <cffunction name="onError" returnType="void"> 
             <cfargument name="Exception" required="true" /> 
             <cfargument name="EventName" type="string" required="true" /> 
             <h1>onError Test</h1>
             <cfdump var="#Exception#" />
         </cffunction>
    </cfcomponent>

    // test class
    public class MyClass {
        public void myMethod() {
            throw new NoClassDefFoundError ("Testing...");
        }
    }

<小時(shí)>

更新

Any 類型包括 Java 對(duì)象類型的所有錯(cuò)誤java.lang.異常.它不包括 java.lang.Throwable 錯(cuò)誤.要捕獲 Throwable 錯(cuò)誤，請(qǐng)?jiān)?cfcatch 中指定 java.lang.Throwable標(biāo)簽類型屬性

The Any type includes all error with the Java object type of java.lang.Exception. It does not include java.lang.Throwable errors. To catch Throwable errors, specify java.lang.Throwable in the cfcatch tag type attribute

盡管文檔說了什么，捕獲 Throwable 在我(或您的)的任何測(cè)試中都不起作用.這強(qiáng)烈表明行為或文檔中存在錯(cuò)誤.無論哪種方式，它都不像宣傳的那樣工作，所以如上所述，我所知道的唯一替代方法是使用通用錯(cuò)誤處理程序.如果您出于某種原因必須堅(jiān)持使用 Application.cfm 文件，請(qǐng)嘗試使用 <cferror type="exception" ...>

Despite what the documentation says, catching Throwable does not work in any of my tests (or yours). That strongly suggests a bug in the behavior or the documentation. Either way it does not work as advertised, so as mentioned above, the only alternative I know of is using a general error handler. If you must stick with an Application.cfm file for some reason, try using <cferror type="exception" ...>

(荒謬)測(cè)試用例:

<cftry>
   <cfset myJavaObject = createObject("java", "path.to.MyClass")>
   <cfset myJavaObject.myMethod()>
   <cfcatch type="java.lang.NoClassDefFoundError">
      CAUGHT java.lang.NoClassDefFoundError
   </cfcatch>
   <cfcatch type="java.lang.LinkageError">
      CAUGHT java.lang.LinkageError
   </cfcatch>
   <cfcatch type="java.lang.Error">
      CAUGHT java.lang.Error
   </cfcatch>
   <cfcatch type="java.lang.Throwable">
      CAUGHT java.lang.Throwable 
   </cfcatch>
   <cfcatch type="any">
      CAUGHT ANY
   </cfcatch>
   <cfcatch>
      CAUGHT
   </cfcatch>
</cftry>

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