Singleton
Singleton is the less useful feature of Jeta. You can use it if you feel too lazy and, for example, in tests when you need a thread-safe singleton.
@Singleton
public class SingletonSample {
public static SingletonSample getInstance() {
return MetaHelper.getSingleton(SingletonSample.class).getSingleton();
}
}
Multiton
Unlike Singleton, Multiton solves quite complex problem. If you’ve ever tried to implement a thread-safe multiton pattern, you would probably know. If you haven’t, you can read this thread on StackOverFlow to be aware.
@Multiton
public class MultitonSample {
static MultitonMetacode<MultitonSample> multiton =
MetaHelper.getMultiton(MultitonSample.class);
public static MultitonSample getInstance(String key) {
return multiton.getMultiton(key);
}
private Object key;
MultitonSample(Object key) {
this.key = key;
}
}
For the performance reasons we hold multiton metacode in a static field.
The helper methods would be:
public static <M> getSingleton(Class<M> masterClass) {
return new SingletonController<>(getInstance().metasitory, masterClass).getSingleton();
}
public static <M> MultitonMetacode<M> getMultiton(Class<M> masterClass) {
return new MultitonController<>(getInstance().metasitory, masterClass).getMetacode();
}
