exception

python try:except:finally

由 让人想犯罪 __ 提交于 2020-04-05 07:25:12
问题 # Open new file to write file = None try: file = open(filePath, 'w') except IOError: msg = ("Unable to create file on disk.") file.close() return finally: file.write("Hello World!") file.close() The above code is ripped from a function. One of the user's system is reporting an error in line: file.write("Hello World!") error: AttributeError: 'NoneType' object has no attribute 'write' Question is, If python is failed to open given file, 'except' block executes and it has to return, but control

Ascertain reason for Channel Fault in WCF+NamedPipes

由 痴心易碎 提交于 2020-03-31 18:00:54
问题 I have a whole sequence of interlinked questions. I would like to know answers for all of them independantly, so *yes*, some of them appear to be X-Y questions; but I do want to know the solution to them anyway!. See end of question for list of other questions in this set. How do I determine the reason for a Channel Fault, e.g. caused by closing the exe on one end of a DuplexChannel connected by named pipes? I have two exes running; communicating over named pipes, via WCF. (If it's relevant,

What does “Fatal error: Unexpectedly found nil while unwrapping an Optional value” mean?

由 限于喜欢 提交于 2020-03-28 06:54:28
问题 My Swift program is crashing with EXC_BAD_INSTRUCTION and one of the following similar errors. What does this error mean, and how do I fix it? Fatal error: Unexpectedly found nil while unwrapping an Optional value or Fatal error: Unexpectedly found nil while implicitly unwrapping an Optional value This post is intended to collect answers to "unexpectedly found nil" issues, so that they are not scattered and hard to find. Feel free to add your own answer or edit the existing wiki answer. 回答1:

What is the reason for my NullPointerException?

由 萝らか妹 提交于 2020-03-26 05:22:28
问题 In my program I have a class called Hive which contains Honey, Pollen, royalJelly and an arraylist of several types of bees. Some of the bee types have an eat method which is pretty much identical between them with the difference being in what they eat or the quantity they eat. Each bee has an anotherDay method which calls the eat method on the bee and in thehive's anotherDay method it loops through the arraylist calling each bees anotherDay. My Queen bees eat runs perfectly however, when I

Difference between “throw new Exception” and “new Exception”?

由 半城伤御伤魂 提交于 2020-03-21 16:22:06
问题 I am interested to know best practice to use throw new Exception() and new Exception() . In case of using new Exception() , I have seen that code moves to next statement instead of throwing exception. But I am told that we should use new Exception() to throw RuntimeException . Can anyone throw some light on this ? 回答1: new Exception() means create an instance (same as creating new Integer(...)) but no exception will happen until you throw it... Consider following snippet: public static void

Difference between “throw new Exception” and “new Exception”?

由 和自甴很熟 提交于 2020-03-21 16:21:14
问题 I am interested to know best practice to use throw new Exception() and new Exception() . In case of using new Exception() , I have seen that code moves to next statement instead of throwing exception. But I am told that we should use new Exception() to throw RuntimeException . Can anyone throw some light on this ? 回答1: new Exception() means create an instance (same as creating new Integer(...)) but no exception will happen until you throw it... Consider following snippet: public static void

Could not load SWT library on Windows 32-bit

由 故事扮演 提交于 2020-03-21 11:52:08
问题 I am almost done with one Java project that I have been developing on Linux. Now I need to build and test it on Windows. So I have installed Eclipse on Windows XP 32-bit, and imported my project. All dependencies of project are in jar files in lib folder, and on Linux everything works well, but on Windows XP I get following error: Exception in thread "main" java.lang.UnsatisfiedLinkError: Could not load SWT library. Reasons: no swt-pi-gtk-4234 in java.library.path no swt-pi-gtk in java

Spring框架知识总结-注入Bean的各类异常

由 ℡╲_俬逩灬. 提交于 2020-03-18 11:26:36
某厂面试归来，发现自己落伍了！>>> 近日整合sping和hibernate框架时遇到了一系列的异常，本次主要说明一下spring框架可能出现的异常及解决方案。 我们借助sping强大的bean容器管理机制，通过BeanFactory轻松的实现javabean的生命周期管理，然而在配置管理的时候难免会遇到一些异常： 异常1：No qualifying bean of type […] found for dependency 例如将BeanB自动注入到BeanA @Component public class BeanA { @Autowired private BeanB dependency; … } 如果此时BeanB没有定义在sping的Cntextl里，那么在启动时候就会抛出异常： the no such bean definition exception : org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.baeldung.packageB.BeanB] found for dependency: expected at least 1 bean which qualifies as autowire candidate

Using Spring Boot's ErrorController and Spring's ResponseEntityExceptionHandler correctly

由 余生颓废 提交于 2020-03-17 09:14:51
问题 The Question When creating a controller in Spring Boot to handle all errors/exceptions in a custom way, including custom exceptions , which technique should be preferred? Should the controller implement the Spring Boot's ErrorController ? Should the controller extend Spring's ResponseEntityExceptionHandler ? Both: a single controller implementing and extending both classes including both of their functionality? Both: two separate controllers, one implementing ErrorController , the other

Using Spring Boot's ErrorController and Spring's ResponseEntityExceptionHandler correctly

由 徘徊边缘 提交于 2020-03-17 09:14:21
问题 The Question When creating a controller in Spring Boot to handle all errors/exceptions in a custom way, including custom exceptions , which technique should be preferred? Should the controller implement the Spring Boot's ErrorController ? Should the controller extend Spring's ResponseEntityExceptionHandler ? Both: a single controller implementing and extending both classes including both of their functionality? Both: two separate controllers, one implementing ErrorController , the other
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