assert

I would like to check constructor arguments and refuse to construct throwing IllegalArgumentException in case the arguments set is not valid (the values don't fit in expected constraints). How to code this in Scala? missingfaktor In Scala, the whole body of the class is your primary constructor, so you can add your validation logic there. scala> class Foo(val i: Int) { | if(i < 0) | throw new IllegalArgumentException("the number must be non-negative.") | } defined class Foo scala> new Foo(3) res106: Foo = Foo@3bfdb2 scala> new Foo(-3) java.lang.IllegalArgumentException: the number must be

一、前言 今天事不是很多，正好在Java交流群里，看到一个比较有意思的问题，于是花了点时间研究了一下，这里做个简单的分享。 先贴一份测试代码，大家可以先猜测一下，执行结果会是怎样的： 2 3 import java.util.concurrent.TimeUnit; 4 5 6 public class TestClassLoading { 7 public static class A{ 8 static { 9 System.out.println("class A init"); 10 try { 11 TimeUnit.SECONDS.sleep(1); 12 } catch (InterruptedException e) { 13 e.printStackTrace(); 14 } 15 new B(); 16 } 17 18 public static void test() { 19 System.out.println("aaa"); 20 } 21 } 22 23 public static class B{ 24 static { 25 System.out.println("class B init"); 26 new A(); 27 } 28 29 30 public static void test() { 31 System.out.println(

挖坑。 来源： https://www.cnblogs.com/saurywb/p/11374109.html

DELPHI微信支付代码 不管是微信支付还是支付宝支付， 3个最棘手的问题是： 1，如何生成签名 2，支付请求如何提交 3, 如何验证签名 下面就围绕这二个问题来讲。 我使用的是XE3. 先看微信支付： 1，微信支付的签名生成 uses IdHashMessageDigest, NatvieXml; //我使用的是NativeXml4.07 function TMicroPayParamBuilder.GetSign: string; var Digest: TIdHashMessageDigest5; utf8: UTF8String; begin utf8 := ''; Assert(FAppId <> '', '公众账号ID 不能为空！'); utf8 := utf8 + 'appid=' + FAppId; if FAttach <> '' then utf8 := utf8 + '&attach=' + FAttach; Assert(FAuthCode <> '', '授权码 不能为空！'); utf8 := utf8 + '&auth_code=' + FAuthCode; Assert(FBody <> '', '商品描述 不能为空！'); utf8 := utf8 + '&body=' + FBody; if FDetail <> '' then utf8 :=

I have discovered that these seem to be the two main ways of testing for exceptions: Assert.Throws<Exception>(()=>MethodThatThrows()); [ExpectedException(typeof(Exception))] Which of these would be best? Does one offer advantages over the other? Or is it simply a matter of personal preference? The first allows you to test for more than one exception, with multiple calls: Assert.Throws(()=>MethodThatThrows()); Assert.Throws(()=>Method2ThatThrows()); The second only allows you to test for one exception per test function. Alexander Stepaniuk The main difference is: ExpectedException() attribute

Is there a way to add or edit the message thrown by assert? I'd like to use something like assert(a == b, "A must be equal to B"); Then, the compiler adds line , time and so on... Is it possible? A hack I've seen around is to use the && operator. Since a pointer "is true" if it's non-null, you can do the following without altering the condition: assert(a == b && "A is not equal to B"); Since assert shows the condition that failed, it will display your message too. If it's not enough, you can write your own myAssert function or macro that will display whatever you want. Andrei Bozantan Another