A Constructor which has parameters in it called as Parameterized Constructors, this constructor is used to assign different values for the different objects. In the below example we have a constructor for the Car class which takes in the the value and sets to the property, lets try to set the value for the property “carColor” [Read more…]
In this article lets take a look into Autowiring by constructor, This type of Autowiring is similar to Autowiring byType , but type applies to constructor arguments. Spring framework tries to match the arguments of the Constructor to the bean type in the configuration file, If a bean is found then Spring injects the object. If not found then it will throw exception.
In my previous article we have seen how to use Class.newInstance() method in creating object for class dynamically but there exist a problem the newInstance() method of Class class can invoke only no-arg constructor of the class when a class has parameterized constructors we cannot use newInstance() method of Class class at that place we need to go for the newInstance() method of the Constructor class. Here also we will load the class using Class.forName() method and get the class instance and get the constructor in the class. Lets see how we can achieve it. [Read more…]
This is one of the frequently asked interview question. No, We cannot have a Constructor defined in an Interface. A method in a interface will be public and abstract by default to provide 100% abstraction and the implementation(method body) will be provided by the implementing class.In this article we will get to know why Constructors are not allowed in Interface. [Read more…]
Constructor is a special method in Java which is used to initialize the object. It looks like a normal method however it is not. A normal java method will have return type whereas the constructor will not have an explicit return type. A constructor will be called during the time of object creation (i.e) when we use new keyword follow by class name. [Read more…]