Questions related to handling errors and exceptions. According to Wikipedia, Exception handling is the process of responding to the occurrence, during computation, of exceptions – anomalous or exceptional events requiring special processing – often changing the normal flow of program execution. It ...

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0answers
31 views

Fix java.lang.NullPointerException? .setColor(c) [closed]

Code: JPanel randomPreview; {..} **66-70** public void showPreview(int pX, int pY, int pCol, JPanel pPanel) { Graphics g = pPanel.getGraphics(); Color c = new Color(pCol, pCol, pCol); ...
5
votes
2answers
178 views

Designing exception classes

I'm coding a small library and I'm having some trouble with designing the exception handling. I must say that I am (still) confused by this feature of the C++ language and I tried to read as much as ...
4
votes
1answer
206 views

Should I always return an error code from C functions?

I have the following code in many places in a large application: if (datastruct.data_ok && cur_time > datastruct.start_time && cur_time < datastruct.end_time) { ...
0
votes
2answers
45 views

Catch unusual exceptions on production code for web apps

Lets say I have a web app, and despite my best testing efforts, several of the many thousands of people who uses it will find some way to generate an exception. Sure, I have error handling code for my ...
0
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4answers
58 views

Testing generic errors

I've got a program that validates it's input, and then errors. So far for each kind of error I created a new derived class. But this was getting pretty unwieldy (the input is complex so there are ...
1
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3answers
121 views

Protect memory from a potentially seg faulting function call

How can one safely call a function that might segfault without corrupting the stack or the heap? These SO questions cover using signal handlers and setjmp.h to regain control. Coming back to life ...
2
votes
4answers
85 views

What an application should do when there is an error notifying the user of an error?

Say I have an application, and it writes (among other things) errors to a log file. It's the first place the user would be asked to go and look if there was a problem. Let's also assume that this is a ...
1
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2answers
100 views

Why is there “Unknown error” in real life? [duplicate]

As a programmer, I always try my best to explain what happened in the code when I have to show an error message, for example: try { int a = b / 0; } catch (NumberFormatException ex) { ...
1
vote
2answers
299 views

How should I provide detailed information about an error, if not through HTTP status codes?

This question comes from here. I believe it deserves to be on its own instead of being lost in a long question with multiple points. I'm building an API and find myself limited by HTTP error ...
0
votes
1answer
76 views

How to handle coding errors in my PHP AJAX code?

How do I handle coding errors in my PHP which has no GUI, only an API? I am concerned that I might never know that there are any. Note that only I will develop the client side. This is not a public ...
5
votes
1answer
125 views

What's the best way to handle Windows API errors in response to system messages or when I have nowhere to return them to?

This is going to be a really stupid question and I hope it's fine for Stack Exchange at all, let alone just this part of it... Right now, my custom Table control uses panic() functions that print an ...
0
votes
1answer
53 views

Dealing with error in data - Idempotent approach

A prior question had an answer that interested me from a design perspective. I work in geospatial data and occasionally have to deal with voids when I read these binary files into my product. What is ...
32
votes
3answers
5k views

Is address 0000000C a special address?

When programming sometimes things break. You made a mistake and your program tries to read from a wrong address. One thing that stands out to me that often those exceptions are like : Access ...
2
votes
2answers
80 views

How to implement error handling/returning while streaming a message

Say someone calls a web service on a server, the relevant data is being retrieved in batches and the message is being streamed to the client. In the middle of the message some kind of exception is ...
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votes
3answers
153 views

Could programming ever have existed without error checking? [closed]

I think that in programming error checking is extremely important, not a secondary topic, what if your programme crashes without an error, just silently aborting? What if you must discover a ...
1
vote
2answers
104 views

Recovering a process after illegal instruction exception

Is it possible in theory to recover after a process is mistakenly pointed-out to read from a wrong memory address, rather than terminating it? Let say an error while working with registers lead the ...
0
votes
3answers
108 views

Coerce bad input or always crash early

The general consensus seems to favor the Crash Early approach, the most reputable source being the acclaimed Pragmatic Programmer book. And while I understand and agree with the advice in many ...
8
votes
2answers
608 views

How should I handle logger failures?

In several of our company's applications, we use a custom logger. It's fairly robust, though we may replace it with something like NLog in the future. One of the logger's tasks is to log any ...
2
votes
2answers
105 views

Preferred way of handling errors when loading an object from a file

If I want to load an object from a file, there are a number of things that can go wrong. Thus, one needs a way of handling errors when doing so. In some languages, like haskell, one can return a Maybe ...
0
votes
0answers
42 views

When calculating cyclomatic complexity, should Exception Handling considered? [duplicate]

When calculating the cyclomatic complexity of a piece of code (/method/program), should any Exception Handling be taken into account? For example, if you include a try-catch block in your ...
3
votes
1answer
467 views

MVC: Where is the right place to set error messages?

I have a ASP.NET MVC application where in all my Models have an Errors Property used to store non-validation errors which I than display in my Views. Where is the right place to populate the error ...
28
votes
8answers
1k views

Is it okay to use exceptions as tools to “catch” errors early?

I use exceptions to catch problems early. For example: public int getAverageAge(Person p1, Person p2){ if(p1 == null || p2 == null) throw new IllegalArgumentException("One or more of ...
4
votes
2answers
118 views

Defining error codes

We are designing an error-handling framework for a cryptographic library written in C. The approach we are taking is that relatively few errors are propagated back to the user since on most occasions ...
3
votes
0answers
126 views

Handling and managing error codes

I'm looking for examples of creating, handling and managing error numbers/codes. To understand what I'm takling about, let's take example scenario: (EU - end user, IT - it helpdesk) EU: - (calls IT) ...
4
votes
1answer
209 views

Error Handling Strategies in Multithreaded Environments

TL;DR What error generating and handling strategies do you use in Multithreaded code intended for use by others and why do you use them? If applicable, state what programming paradigm it's useful for. ...
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votes
1answer
117 views

Try and catch error trapping, why is it so significant? [duplicate]

I try to understand why should I "try" a method to catch errors. It looks to me like the concept is: "letting a process run assuming its not properly developed". Should I always assume that a ...
1
vote
2answers
216 views

Is goto to improve DRY-ness OK? [duplicate]

My code has many checks to detect errors in various cases (many conditions would result in the same error), inside a function returning an error struct. Instead of looking like this: err_struct ...
15
votes
2answers
344 views

Cleanest way to report errors in Haskell

I'm working on learning Haskell, and I've come across three different ways of dealing with errors in functions I write: I can simply write error "Some error message.", which throws an exception. I ...
10
votes
6answers
1k views

Designing database related methods, which is better to return: true/false or row affected?

I have some methods that perform some data changing in a database (insert, update, and delete). The ORM I'm using return row-affected int values for those type of method. What should I return for "my ...
1
vote
2answers
648 views

IllegalStateException vs. IllegalArgumentException

In have written a function which expects the caller to pass in a configuration file like XML. Then I parse this given file and extract something which i then return. In this function (at least) two ...
30
votes
4answers
2k views

How much information about an error should be shown to the user?

Applications can always throw errors. If such an error occurs, the user should be notified, because what he asked the application to do has not succeeded. However, how much information should the ...
2
votes
0answers
113 views

Is there a theory for “transactional” sequences of failing and no-fail actions?

My question is about writing transaction-like functions that execute sequences of actions, some of which may fail. It is related to the general C++ principle "destructors can't throw," no-fail ...
1
vote
2answers
317 views

global try-catch in presentation layer

I have a 3-layered app structured as follows. Presentation Layer (ASP.NET MVC project) Business Logic Layer (Services for controllers in PL) Data Access Layer (Repositories) Each Controller in PL ...
3
votes
2answers
202 views

What is better to return from the DataService: Status or Exceptions?

I have a MVVM app with DataServices (using mvvmlight). Right now, i'm using it like var answer = await myDataService.PullList(categoryId); if (answer.Status == Ok) ...
2
votes
1answer
85 views

How to handle errors best addressed in a higher abstraction layer and dependent on state inferred in current layer?

I have a use-case that can be repaired, but the logic for repairing it is best done in a higher level of abstraction. Just throwing exception/failure is ugly because it's hard to pass back up through ...
2
votes
1answer
571 views

Passing multiple errors back from service layer

I am using Spring for a web application. To validate a user's input in a form such as for creating a Person entity I user JSR 303 validation to check for not null/empty or valid patterns etc.. Some ...
3
votes
6answers
1k views

Whats the best way to handle errors in code?

So I'm a little concerned about my error handling... Currently my execution path looks something like this: Users.aspx -> App_Code/User.cs -> Data Layer/User.cs So now when I try to update a ...
0
votes
2answers
55 views

Handling ignorable failure conditions in a method

I'm working on a coarse API for performing higher level business functions. Under many conditions these functions may fail in a way that is expected (not exceptional), ie. the function may not be ...
5
votes
5answers
1k views

How should I handle exception that *should* never be thrown? [duplicate]

What is the best way to handle errors that shouldn't ever happen? My current way to do this is to throw an exception if the 'thing that shouldn't happen' does happen, like so: /* * Restoring from a ...
2
votes
1answer
210 views

Error Handling when no access to Visual Studio or application start point

I've recently joined a project where we are extending the functionality of an external application that our company has bought. It is an Office Add-In with an admin console that allows you to create ...
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votes
1answer
179 views

Functions returning either “OK” or “error message” instead of procedures

I have joined writing middle-size multi-purpose database application as co-lead. It currently has about 150 tables (and growing) and overall functionality you can imagine as very small ERP. At many ...
1
vote
1answer
76 views

Automating form error handling

I'm not sure if I'm being clever or making things more difficult. I'm working within a custom MVC framework, and within some of my "views" which contain forms I'm preserving input and styling errors ...
3
votes
1answer
104 views

Invalid data returned, which HttpCode to return?

My web application calls a third party API. If I successfully call the API but invalid data is returned which cannot be processed by my system what is the most appropriate HttpCode to return to the ...
0
votes
0answers
82 views

Check some value between each function call

Can you recommend a nice way of checking a particular value between calls to a set of functions? E.g. something like this in Python (might not be terribly 'Pythonic'): self.error_code = 0 # this ...
1
vote
1answer
55 views

Partial recovery from an Exception [duplicate]

I have seen Exception Handling blocks that they were throwing the recently caught Exception in the catch block. Something like: } catch ( Exception $e ) { // Do some recovery here ...
2
votes
2answers
3k views

Python - assert vs if & return

I am writing a script that does something to a text file (what it does is irrelevant for my question though). So before I do something to the file I want to check if the file exists. I can do this no ...
0
votes
5answers
317 views

Fail-fast paradigm overheads

Fail-fast seems like a right way since it simplifies bug detection. But it's a harm for performance cause of multiple checking the same thing at several levels of the system. Simple example. There is ...
5
votes
3answers
1k views

Authoritative sources for exception handling best practices [closed]

My work place suffers from a bad case of the Pokemon Exception Handling anti-pattern with constructs like the following splattered across the code base: try { ... } catch (Exception ex) { // ...
7
votes
2answers
780 views

What's the difference between robustness and fault-tolerance?

Systems / programs / distributed algorithms / ... are often described with the predicate robust or fault-tolerant. What is the difference? Details: When I google for +robust +"fault-tolerant", I ...
9
votes
4answers
772 views

Is error suppressing bad practice?

On a SO question I asked here about some code I was unsure about, someone replied "BTW, horrible code there: it uses the error suppressing symbol (@) a lot." Is there a reason why this is bad ...