JarCastingMixja
Java library implementing Mixtures (also known as IIFE or Immediately-Invoked Function Expressions) - Setup objects without needing private methods or using double brace initialization anti-pattern. Readable, efficient and safe way to construct ArrayLists, HashMaps, your own Objects, and more!
How to Install
Add the following line to your pom.xml
<dependency>
<groupId>com.andyln</groupId>
<artifactId>mixja</artifactId>
<version>1.0.0</version>
</dependency>
Examples
mix - Creates an object that may require additional put/add/setters/etc. Java Lambda used to setup and return this object.
import static com.andyln.Mixja.mix;
...
private Map<String, String> map = mix(() -> {
Map<String, String> map = new HashMap<>();
map.put("Grace", "Hopper");
map.put("Ada", "Lovelace");
map.put("Alan", "Turing");
return map;
});
eix - checked (e)xception may be thrown (m)ix. The performance of try-catch is why this method is standalone.
import static com.andyln.Mixja.eix;
...
private Set<String> brokenSet = eix(() -> {
Set<String> set = mock(Set.class);
when(set.add(anyString())).thenThrow(new UnsupportedOperationException());
return set;
});
FAQ - Readings
Q: When should I use a Mixture or Immediately-Invoked Function Expression (IIFE)?
A: Avoids needing to create named functions. Cleaner code by encapsulating variables. IIFE are
- Anonymous - You don't have to make a name for your function.
- Brief - Code is easy to read due to its "one-time-use" nature.
- Inline - Code is viewed exactly where it is used. No need to jump around code base to see functionalty.
Q: Are there any more resources where I can learn about IIFE?
A: Here are some of my recommended reading links (Note: These reading links are JavaScript specific, Java examples are in FAQ - Usages below):
- https://developer.mozilla.org/en-US/docs/Glossary/IIFE
- https://www.youtube.com/watch?v=3cbiZV4H22c (Video)
- http://adripofjavascript.com/blog/drips/an-introduction-to-iffes-immediately-invoked-function-expressions.html
FAQ - Usages
Q: Why use this library instead of just using Map.of(...)?
A: You should use Of(...) when possible! This library helps solves several problems not covered by that syntax.
- Can setup objects that are not part of Collections. Usable with your own classes or classes from your dependencies.
CustomObject customObject = mix(() -> {
CustomObject customObject = new CustomObject();
customObject.setName("Awesome");
customObject.setFeature(new Feature());
customObject.setDate("March 31, 2020");
return customObject;
});
Of(...)syntax is only available on Java 9+. Can use this library on Java 8.
Q: Can't I just use a Builder?
A: This library can deliver similar results to a Builder, but will also provide the following additional benefits:
- API delivers on use cases that a Builder may not inherently provide.
Toaster usedToaster = mix(() -> {
Toaster toaster = new Toaster();
toaster.add(new Bread());
toaster.add(new Bagel());
toaster.toast();
toaster.removeAll();
return toaster;
});
- Allows you to maintain fewer Builder classes and annotations