Exercise: apartment owners

Specification:

Realize a Java class whose objects maintain some information on the owners of apartments. Each object of the class should contain a string that indicates the name of the owner, and an array of 10 slots of type string, indexed by the numbers from 0 to 9, that can contain each the address of an apartment owned by that owner (or null, if the slot is empty). The class should export the following functionalities:

• a constructor that takes as parameter the name of the owner, and creates an object with the specified owner and in which all slots of the array are initially empty;
• a method that returns the owner of an apartment;
• a method that returns the address contained in a slot (or null, if the slot is empty);
• a method to assign the address of an apartment to a slot;
• a method that returns the number of apartments (i.e., of non-empty slots);
• a method that reorganizes the addresses in such a way that they are contained in the first consecutive slots of the array;
• a method toString, that overrides the toString method inherited from Object, and returns a string containing the information about the object.