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誤，而不是在 Application.cfc 的 OnError 函數中.

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

現在我喝了更多的咖啡，我不認為 cfcatch 能夠捕獲 NoClassDefFoundError.根據文檔，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，例如數據庫操作失敗、丟失包括文件和開發人員指定的事件.

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 錯誤.

一個錯誤表示嚴重的問題，一個合理的應用程序不應該試圖抓住

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"問題而設計的.一旦你得到 NoClassDefFoundError，你真的無能為力.這是一個嚴重的錯誤，你無法克服它(在正常情況下).您最多只能顯示錯誤消息并退出.

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 等未捕獲的錯誤以及異常.所以我認為你能做的最好的就是實現 onError 并讓它顯示一個錯誤頁面.

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>

更新

Any 類型包括 Java 對象類型的所有錯誤java.lang.異常.它不包括 java.lang.Throwable 錯誤.要捕獲 Throwable 錯誤，請在 cfcatch 中指定 java.lang.Throwable標簽類型屬性

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)的任何測試中都不起作用.這強烈表明行為或文檔中存在錯誤.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誤處理程序.如果您出于某種原因必須堅持使用 Application.cfm 文件，請嘗試使用 <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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