runtime | 易学教程

Is it possible to retrieve the call stack programmatically in VB6?

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问题 When an error occurs in a function, I'd like to know the sequence of events that lead up to it, especially when that function is called from a dozen different places. Is there any way to retrieve the call stack in VB6, or do I have to do it the hard way (e.g., log entries in every function and error handler, etc.)? 回答1: I'm pretty sure you have to do it the hard way. At a previous job of mine, we had a very elegant error handling process for VB6 with DCOM components. However, it was a lot

Redirect Runtime.getRuntime().exec() output with System.setOut();

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问题 I have a program Test.java: import java.io.*; public class Test { public static void main(String[] args) throws Exception { System.setOut(new PrintStream(new FileOutputStream("test.txt"))); System.out.println("HelloWorld1"); Runtime.getRuntime().exec("echo HelloWorld2"); } } This is supposed to print HelloWorld1 and HelloWorld2 to the file text.txt. However, when I view the file, I only see HelloWorld1. Where did HelloWorld2 go? Did it vanish into thin air? Lets say I want to redirect

java 通配符的使用-upcast

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【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> package localevidence; //: generics/UnboundedWildcards1.java //: generics/CovariantArrays.java class Fruit {} class Appleee extends Fruit {} class Jonathan extends Appleee {} class Orange extends Fruit {} public class Testwildcats { public static void main(String[] args) { Fruit[] fruit = new Appleee[10]; fruit[0] = new Appleee(); // OK fruit[1] = new Jonathan(); // OK // Runtime type is Appleee[], not Fruit[] or Orange[]: try { // Compiler allows you to add Fruit: fruit[0] = new Fruit(); // ArrayStoreException } catch(Exception e) { System.out.println(e); }

non-fragile：oc2.0特性--继承结构的父类内存布局变化时子类是否需要重新编译的问题

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Runtime Versions and Platforms There are different versions of the Objective-C runtime on different platforms. Legacy and Modern Versions There are two versions of the Objective-C runtime—“modern” and “legacy”. The modern version was introduced with Objective-C 2.0 and includes a number of new features. The programming interface for the legacy version of the runtime is described in Objective-C 1 Runtime Reference; the programming interface for the modern version of the runtime is described in Objective-C Runtime Reference . The most notable new feature is that instance variables in the modern

Change a method at runtime via a hot swap mechanism

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问题 Assume we have a trivial Java program that consists of just one class: public class HelloWorld { private static void replacable(int i) { System.out.println("Today is a nice day with a number " + i); } public static void main(String[] args) throws Exception { for(int i = 0; i < 100000; ++i) { replacable(i); Thread.sleep(500); } } After it's compiled and run, output will be this: Today is a nice day with a number 0 Today is a nice day with a number 1 Today is a nice day with a number 2 Today is

Change a method at runtime via a hot swap mechanism

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running a vbs file from java

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问题 I have a VBS file test.vbs in C:/work/selenium/chrome/ and I want to run it from my Java program, so I tried this but with no luck: public void test() throws InterruptedException { Runtime rt = Runtime.getRuntime(); try { Runtime.getRuntime().exec( "C:/work/selenium/chrome/test.vbs" ); } catch( IOException e ) { e.printStackTrace(); } } If I try to run some exe file with this method it runs well, but when I try to run a VBS file it says "not a valid win32 application". Any idea how to run a

running a vbs file from java

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.NET Core开发日志——依赖注入

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依赖注入(DI)不是一个新的话题，它的出现是伴随着系统解耦的需要而几乎必然产生的。在SOLID设计原则中，DIP(Dependency inversion principle)——依赖倒置，规定了“需依赖抽象，而非实现”的准则，该原则主要目的是通过引入抽象(比如接口)的方式降低模块之间的耦合性。与此原则相拟而又有所不同的是IoC(inversion of control)——控制反转设计原则。这项原则定义了应该由通用框架而非外部代码决定控制流(control flow)的概念。对控制反转的实现有数种技术，DI(Dependency injection)——依赖注入便是其中之一，而依赖注入技术同时又支持依赖倒置的设计原则，所以它被广泛使用并不是件令人意外的事情。依赖注入的基本特性是借由一个对象提供对另一对象的依赖。这样的一个对象通常又被称为容器。容器负责被依赖对象的注册(register)，解析(resolve)与释放(release)，并具有将被依赖对象注入到依赖对象内部的功能。在之前的ASP.NET开发过程中，要想使用到依赖注入技术必需依赖第三方类库，而在ASP.NET Core中，这项技术已经被引入到其自身的框架中。容器 ASP.NET Core中使用ServiceProvider作为依赖注入的容器，它是在WebHostBuilder类中被引入的。 public

Go 开发关键技术指南 | Go 面向失败编程 (内含超全知识大图）

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作者 | 杨成立（忘篱）阿里巴巴高级技术专家关注“阿里巴巴云原生”公众号，回复 Go 即可查看清晰知识大图！导读：从问题本身出发，不局限于 Go 语言，探讨服务器中常常遇到的问题，最后回到 Go 如何解决这些问题，为大家提供 Go 开发的关键技术指南。我们将以系列文章的形式推出《Go 开发的关键技术指南》，共有 4 篇文章，本文为第 2 篇。 Could Not Recover 在 C/C++ 中，最苦恼的莫过于上线后发现有野指针或内存越界，导致不可能崩溃的地方崩溃；最无语的是因为很早写的日志打印，比如 %s 把整数当字符串，突然某天执行到了崩溃；最无奈的是无论因为什么崩溃都导致服务的所有用户受到影响。如果能有一种方案，将指针和内存都管理起来，避免用户错误访问和释放，这样虽然浪费了一部分的 CPU，但是可以在快速变化的业务中避免这些头疼的问题。在现代的高级语言中，比如 Java、Python 和 JS 的异常，以及 Go 的 panic-recover 都是这种机制。毕竟，用一些 CPU 换得快速迭代中的不 Crash，怎么算都是划得来的。哪些可以 Recover Go 有 Defer, Panic, and Recover 。其中 defer 一般用在资源释放或者捕获 panic。而 panic 是中止正常的执行流程，执行所有的 defer

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