Why did Java 8 introduce a new date and time API when it already had classes such as Date and Calendar? Below are the main reasons 1.Bad API design. For example, The Date class has both date and time components, if you...
Read MoreFriday, 27 December 2019
Saturday, 14 December 2019
Collection
The collection framework is very important for fresher and experienced developers. You must have a good hold on it if you want to crack java interviews. You are supposed to prepare theoretical, coding and scenario-based questions related to this topic. I will...
Read MoreTuesday, 22 October 2019
Dependency Injection
What is Dependency Injection aka Inversion of control? Let's understand first "coupling". When one class depends on another, they are called coupled. Coupled class can't be tested in isolation. For example: Client depends on BookService, BookService depends on BookDAO, BookDAO depends on...
Read MoreSunday, 6 October 2019
Expectations
The expectation from Core a Java Developer General General expectation of client from core java developer is he should strong in Data structure , multithreading and fundamental , client expect when complex question asked from candidate he should attempt and try to...
Read MoreJava 8 features
Agenda Lambda Expression Functional Interface Default Method Inbuilt functional interfaces 1.Consumer 2.Supplier 3.Function 4.Predicate Double colon operator(::) Stream...
Read MoreSaturday, 5 October 2019
Wrapper classes
Agenda Wrapper classes The class hierarchy of wrapper class Creating an object of the wrapper classes Wrapper classes The wrapper classes are used to wrap primitives in an object. So, they can be added to a collection object. To define utility functions...
Read MoreSunday, 22 September 2019
Saturday, 21 September 2019
Double colon operator
Method and Constructor reference by using "::" operator The functional interface method can be mapped to our specified method by using "::" operator. This is called method reference. Our specified method can be either a static or instance method. The functional interface...
Read MoreJava 8 in built functions
IN BUILT FUNCTIONS Consumer,Supplier,Function and Predicate all are available under java.util.function package. Comparison of in built functions Properties Consumer Supplier Function Predicate Purpose To consume some input and perform required operation.It won’t return anything To supply some value base on requirement To...
Read MoreFriday, 20 September 2019
Default method
Default Methods In Java 1.8v onwards, you can also define the default method inside the interface. You can define the default method using the keyword default. Default methods are by default available to all implementation classes. Based on our business requirement implementation...
Read MoreTuesday, 17 September 2019
Generic concept
Agenda Introduction Generic Classes Bounded types Generic methods and wild card character Conclusion Introduction The generic concept is introduced in Java 1.5v To resolve two problems of collection. Type safety ClassCastException ArrayList list = new ArrayList();//Non generic a.k.a raw type version till...
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