try-catch

问题 I am trying to parse dates using SimpleDateFormat . As my service takes in multiple date formats, I have adopted this approach: String[] formats = { "yyyy-MM-dd'T'HH:mm:ss.SSSZ", "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'", "yyyy-MM-dd'T'HH:mm:ss.SSS-HH:mm", "EEE MMM dd HH:mm:ss Z yyyy"}; for (String format : formats) { try { return new SimpleDateFormat(format).parse(dateString); } catch (ParseException e) {} } return null; The rationale behind the try-catch is that if the current date format couldn't

问题 I am simply using a cftry/cfcatch block for handling any exception. Take this simple exception: <cftry> <cfset abc = 1/0> <cfcatch> <cfdump var="#cfcatch.getClass().getName()#"> <cfdump var="#isStruct(cfcatch)#"> <cfdump var="#isObject(cfcatch)#"> <cfdump var="#structKeyExists(cfcatch, 'type')#"> </cfcatch> </cftry> And the above code's output is like this: coldfusion.runtime.DivideByZeroException NO YES YES My question is: Why structKeyExists is not throwing an error as cfcatch is not of

问题 I was reading this link for try-with-resources and it says: The close method of the Closeable interface throws exceptions of type IOException while the close method of the AutoCloseable interface throws exceptions of type Exception . But why? The close method of AutoCloseable could have also thrown IOException is there any example that support that close method of AutoCloseable must throw exceptions of type Exception 回答1: The AutoClosable interface is located in java.lang and is intended to

问题 I have a foreach loop that breaks during the loop in the condition of the foreach itself. Is there a way to try catch the item that throws the exception and then continue the loop? This will run a few times until the exception hits and then end. try { foreach(b in bees) { //exception is in this line string += b; } } catch { //error } This will not run at all because the exception is in the condition of the foreach foreach(b in bees) { //exception is in this line try { string += b; } catch { /

问题 I was trying with a simple code using org.testng.Assert to assert 2 use-cases. In the first use-case I am asserting 2 unequal values which Fail correctly. But in the second use-case when I am asserting 2 unequal values within the try-catch block, the result is always returned as Pass My code is as follows: package demo; import org.testng.Assert; import org.testng.annotations.Test; public class Q43710035 { @Test public void test1() { System.out.println("Within test1"); int a = 12; int b =20;

问题 i'm pretty new to erlang and i'm trying to get a basic try / catch statement to work. I"m using webmachine to process some requests and all i really want to do is parse some JSON data and return it. In the event that the JSON data is invalid, I just want to return an error msg. Here is the code I have so far. (the JSON data is invalid) to_text(ReqData, Context) -> Body = "{\"firstName\": \"John\"\"lastName\": \"Smith\"}", try decode(Body) of _ -> {"Success! Json decoded!",ReqData,Context}

问题 I've seen this pattern a few times now: bool success = false; try { DoSomething(); success = true; } finally { if (!success) Rollback(); } And I've been wondering: Why is this better than using catch for rollbacks? try { DoSomething(); } catch { Rollback(); throw; } What are the differences between the two ways of making sure changes are rolled back on failure? 回答1: The clear goal here is to cause Rollback to be called in the event of any error. Both code snippets accomplish this goal. The

问题 TL;DR: how to raise a previously caught exception later on, while preserving the original exception's stacktrace. Since I think this is useful with the Result monad or computation expression, esp. since that pattern is often used for wrapping an exception without throwing it, here's a worked out example of that: type Result<'TResult, 'TError> = | Success of 'TResult | Fail of 'TError module Result = let bind f = function | Success v -> f v | Fail e -> Fail e let create v = Success v let

问题 In the below code, the IDE alerts me about "Missing return statement" in the last bracket. Which leads me to ask here if the return inside the try{} is ok or should be outside it. Thanks a lot. public function getFileNamesFromKeywords( array $ids, $format ) { try { if(self::$dbLink) { $ids = implode(',',$ids); $query = 'SELECT d.id, d.wfid, d.docid , k.keyword, k.value'. 'FROM keywords k'. 'INNER JOIN documents d '. 'ON k.document_id = d.id'. 'WHERE k.document_id IN ('.$ids.')'; $results =

问题 This question already has answers here : Closed 8 years ago . Possible Duplicates: Why are empty catch blocks a bad idea? Is there any valid reason to ever ignore a caught exception Do you know any situations when an empty catch block is not the absolute evil? try { ... // What and When? ... } catch { } 回答1: There are a lot of questions on this, try to look at: Why are empty catch blocks a bad idea? From that post's accepted answer: Usually empty try-catch is a bad idea because you are