StrictMocks in Mockito

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Today someone asked how to verify that only your stubbed interactions occur, and no others (when using Mockito). I have heard this asked this quite often, especially by people used to JMock where mocks are strict by default. I’d be interested in knowing if there’s an out of the box way of doing this. The… Read more »

InstanceOf “Smart Casts” with Java 8 Lambdas

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As with try-as-expression, there are many other language features we can simulate with Lambdas. Another example is removing the cast commonly needed with instanceof. Kotlin has a nice feature called smart casts, which allows you to do if (x instanceof Duck) { x.quack(); } if (x instanceof Duck) { x.quack(); } Where x is “casted”… Read more »

Try as Expression in Java 8

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I’ve been familiarising myself with the new Java 8 language features. It’s great how much easier it is to work around language limitations now that we have lambdas. One annoyance with Java is that try blocks cannot be used as expressions. We can do it with “if” conditionals using the ternary operator. String result =… Read more »

JavaScript shell scripting with Nashorn

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One of the nice features of Nashorn is that you can write shell scripts in JavaScript. It supports #!s, #comments, reading arguments, and everything there’s a Java library for (Including executing external processes obviously) Here’s an example #!/home/benji/nashorn7/bin/nashorn #this is a comment   print(’I am running from ‘ + __FILE__);   var name = arguments.join(’… Read more »

JavaScript tests with JUnit

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This weekend I have been playing with Nashorn, the new JavaScript engine coming in Java 8. As an exercise I implemented a JUnit runner for JavaScript unit tests using Nashorn. Others have implemented similar wrappers, we even have one at work. None of the ones I have found do everything I want, and it was… Read more »

MultiCatch in c# and old java

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Someone on IRC was asking whether it was possible to do catch multiple types of exceptions at the same time in c#. In Java 7 there’s a feature from project coin called multi catch that enables the following syntax: public class MultiCatch { public static void main(String… args) { try { throw new ExceptionA(); }… Read more »

Jammer – IRC to Yammer Bridge

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Jammer is a quick 1hr project that clones IRC discussion on Yammer. Yammer is a social network for internal use by organisations. It’s a great way to broadcast information and have asynchronous discussion, and simple enough for anyone to use. Developers already have a great forum for asynchronous discussion – IRC. IRC is great for… Read more »

Typesafe Hibernate POJO Queries without code generation

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Hibernate is great, but often one has to specify queries as HQL in Strings, or as criteria which allow building of invalid queries. It would be great to use the java type system to help enforce correct queries. I am aware of some tools to do this, but all the ones I have seen require… Read more »

Java Abuse: Inline instanceof

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One annoyance in Java is having to do instanceof checks on multiple lines. e.g. if (object instanceof Foo) { Foo foo = (Foo)object;; }if (object instanceof Foo) { Foo foo = (Foo)object;; } While this is often a sign of a design failure, there are times when instanceof checks are required often due… Read more »

Java Abuse – Currency Pattern

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Here’s a sillier one from last night… People often complain about not being able to return multiple values from a method in Java. I can’t see a good reason for wanting to do this, but some do. The example I was given was wanting to do: int foo, bar, baz; list(foo, bar, bar) = func(ponies);int… Read more »