exception

问题 I render a list of Objects with freemarker: <ul> <#list publication as item> <li><b>${item.key}</b> : ${item.value}</li> </#list> </ul> but some of the item have a item.value null that raises the exception: freemarker.core.InvalidReferenceException: Expression item.value is undefined on line 12, column 44 in mailTemplate. at freemarker.core.TemplateObject.assertNonNull(TemplateObject.java:125) at freemarker.core.Expression.getStringValue(Expression.java:118) I would like that freemarker

问题 I render a list of Objects with freemarker: <ul> <#list publication as item> <li><b>${item.key}</b> : ${item.value}</li> </#list> </ul> but some of the item have a item.value null that raises the exception: freemarker.core.InvalidReferenceException: Expression item.value is undefined on line 12, column 44 in mailTemplate. at freemarker.core.TemplateObject.assertNonNull(TemplateObject.java:125) at freemarker.core.Expression.getStringValue(Expression.java:118) I would like that freemarker

问题 I have a simple method that prints a command to the screen, scan's a user's input, and returns it as a String. If the user's input is invalid, it notifies the user and asks again. This method worked perfectly but my instructor mentioned that we should always close resources, so I went back and added in the close method and now I'm getting a NoSuchElementException every time the method is called, regardless of user input. Here is the code... private String getUserString(String userCommand) {

问题 Suppose I've got a function foo that performs asynchronous computation and returns a Future : def foo(x: Int)(implicit ec: ExecutionContext): Future[Int] = ??? Now I'd like to retry this computation n times until the computation succeeds. def retryFoo(x: Int, n: Int)(implicit ec: ExecutionContext): Future[Int] = ??? I would like also to return all exceptions thrown while retrying. So, I define new exception class ExceptionsList and require retryFoo to return ExceptionsList when all retries

问题 I have a big and bloated software and I want to add a new GUI element to it. The GUI element was written using XAML and WPF. I created the UI element in a separate assembly, and reference it in the big software. The two projects compiled smoothly under VS2010, but when I run my application I get a TypeLoadException . Looking into the exception with the debugger, I get the following message : Could not load type GUI.Dashboard from assembly GUI, blah, blah . There is no InnerException nor any

问题 I have a big and bloated software and I want to add a new GUI element to it. The GUI element was written using XAML and WPF. I created the UI element in a separate assembly, and reference it in the big software. The two projects compiled smoothly under VS2010, but when I run my application I get a TypeLoadException . Looking into the exception with the debugger, I get the following message : Could not load type GUI.Dashboard from assembly GUI, blah, blah . There is no InnerException nor any

问题 This question already has answers here : Dealing with “java.lang.OutOfMemoryError: PermGen space” error (32 answers) Closed 5 years ago . could anyone say what's wrong with my application? public class HibernateUtil { private static final SessionFactory sessionFactory; static { try { sessionFactory = new AnnotationConfiguration().configure().buildSessionFactory(); } catch (Throwable ex) { System.err.println("Initial SessionFactory creation failed." + ex); throw new ExceptionInInitializerError

问题 I am new at android developing. The project is about implementing an AbstractAccountAuthenticator with an AbstractThreadedSyncAdapter to sync certain data on a server with a content provider. I made everything and both adding accounts and syncing is running without any problems. Now I've tried to add a Preference-Screen just like suggested in the android reference (search for AbstractAccountAuthenticator, it is explained there) via xml like this: autenticator.xml: <account-authenticator xmlns

问题 I've never used the "throws" clause, and today a mate told me that I had to specify in the method declaration which exceptions the method may throw. However, I've been using exceptions without problems without doing it, so, why is it needed if, in fact, it's needed? 回答1: Java has two different types of exceptions: checked Exceptions and unchecked Exceptions. Unchecked exceptions are subclasses of RuntimeException and you don't have to add a throws declaration. All other exceptions have to be

问题 The Problem I'm writing a Cocoa application and I want to raise exceptions that will crash the application noisily. I have the following lines in my application delegate: [NSException raise:NSInternalInconsistencyException format:@"This should crash the application."]; abort(); The problem is, they don't bring down the application - the message is just logged to the console and the app carries on it's merry way. As I understand it, the whole point of exceptions is that they're fired under