exception

问题 I'm considering an optimisation in a particularly heavy part of my code. It's task is to insert statistical data into a table. This data is being hit a fair amount by other programs. Otherwise I would consider using SQL Bulk inserts etc. So my question is... Is it ok to try and insert some data knowing that it might (not too often) throw a SqlException for a duplicate row? Is the performance hit of an exception worse than checking each row prior to insertion? 回答1: First, my advice is to err

问题 This question already has an answer here : Closed 10 years ago . Duplicate: Exception Driven Programming in Java I have been looking at ELMAH and was wondering what kinds of similar applications are available for Java. Thanks for the recommendations for log4j and other frameworks. Like the author of the post this question duplicates, I'm just looking to see if a more full-featured solution exists rather than having to roll my own (which of course I may do if there's nothing comparable). 回答1:

问题 When i run my application for sometime, suddenly the network is getting disconnected and i am getting the unknownhostexception in my application. In that case if i check the browser, the same exception occurs.I don't know why internet is getting disconnected suddenly. It works fine only if i re start the emulator again. If any one knows and provides the solution, it will be very much helpful for everyone. 回答1: See the below link: http://hubpages.com/hub/Tips-to-solve-the-UnknownHostException

问题 I'm currently working on new project, which should provide a web-based API. Of course, there are many cases, when requested operation fails and API should report about reasons of this fail. Previously I used traditional way, when response contains numeric error code and more human-friendly error message, but maintaining error code list and mapping between my codes and internal exceptions was a bit frustrating. I thought that it might be more convenient to use symbolic error codes, for example

问题 I know this question is pretty similar to others that have been posted before but I would like to discuss this topic in a proper way. Do you think that the "obvious" exception should be unit tested? With obvious exception I mean for example exceptions due to null arguments or empty strings or negative numbers in situations where we the business logic of our unit make us obvious that these exceptions will always be thrown at the beginning of our method(s) before any other operation. In other

问题 If I have a exception stored inside std::exception_ptr . I rethrow the exception using std::rethrow_exception , access it using catch(MyException&) and then I modify the value. If I throw the same exception again, should I observe the modification I made? The following code demonstrate my idea: #include <exception> #include <iostream> struct MyException { int value; }; int main() { std::exception_ptr a = std::make_exception_ptr(MyException()); try { std::rethrow_exception(a); } catch

问题 If I have a exception stored inside std::exception_ptr . I rethrow the exception using std::rethrow_exception , access it using catch(MyException&) and then I modify the value. If I throw the same exception again, should I observe the modification I made? The following code demonstrate my idea: #include <exception> #include <iostream> struct MyException { int value; }; int main() { std::exception_ptr a = std::make_exception_ptr(MyException()); try { std::rethrow_exception(a); } catch

问题 This question already has answers here : What is a serialVersionUID and why should I use it? (25 answers) Closed 5 years ago . I'm creating a Java application, and when creating an interface to use with an ADT, it finds the need to initialize a random number as an ID number. public class StackFullException extends RuntimeException { private static final long serialVersionUID = 1L; public StackFullException(){} public StackFullException(String message) { super(message); } } I'm curious as to

问题 Can someone explain to me this StaleDataException 07-11 19:58:23.298 E/AndroidRuntime( 1044): Uncaught handler: thread main exiting due to uncaught exception 07-11 19:58:23.368 E/AndroidRuntime( 1044): android.database.StaleDataException: Access closed cursor 07-11 19:58:23.368 E/AndroidRuntime( 1044): at android.database.AbstractWindowedCursor.checkPosition(AbstractWindowedCursor.java:217) 07-11 19:58:23.368 E/AndroidRuntime( 1044): at android.database.AbstractWindowedCursor.getInt

问题 According to the documentation on sys.exit and SystemExit, it seems that def sys.exit(return_value=None): # or return_value=0 raise SystemExit(return_value) is that correct or does sys.exit do something else before? 回答1: According to Python/sysmodule.c, raising SystemExit is all it does. static PyObject * sys_exit(PyObject *self, PyObject *args) { PyObject *exit_code = 0; if (!PyArg_UnpackTuple(args, "exit", 0, 1, &exit_code)) return NULL; /* Raise SystemExit so callers may catch it or clean