• array.splics(i,1);
  • static class
  • String.getChars

Java

Java Core basics

  • Static block executing before everything use cases.
  • Immutable with date field
  • Clone - deep and shallow
  • this super constructor
  • Immutable Class
  • https://www.journaldev.com/129/how-to-create-immutable-class-in-java/amp
  • http://www.javapractices.com/topic/TopicAction.do?Id=29
  • Immutable with date field
  • Cloneable
  • http://www.cafeaulait.org/course/week4/46.html
  • https://www.geeksforgeeks.org/anonymous-inner-class-java/
  • https://www.geeksforgeeks.org/flow-control-in-try-catch-finally-in-java/

multithreading

  • Bank ATM java multithreading example
  • process vs thread
  • Why multithreading
  • Multithreading vs Concurrency
  • Semaphore
  • Countdown Latch
  • Cyclic barrier
  • Executor For Join
  • Re-enterant Lock
  • Thread - wait notify life cycle
  • Concurrent hashmap
  • Wait and sleep
  • Iterator
  • Fail fast fail safe
  • Double check locking
  • Semaphore
  • ThreadGroup
  • Thread Executors

Fork-Join Frame work

  • ForkJoinPool
  • ForkJoinTask – RecursiveAction (return void)
  • ForkJoinTask – RecursiveTask (return value)
  • Thread Stealing pool
  • invokeAll(), invoke(), execute(), submit()

Collections

LinkedList

  • Internal implementation – DoublyLinkedList that is why ListIterator has reverse

HashMap

  • HashMap internal Working
  • How Linked hashMap works to maintain sequence
  • HashMap implementations
  • Default size HashMap

Java8

  • How jdk8 streams work internally – pipeline
  • Intermediate and terminal operations
  • Stream Student object as Map<city, List<Student>> - [MapStringListOfValues](https://stackoverflow.com/questions/50348166/java-8-list-of-objects-to-mapstring-list-of-valuesNew features in java8
  • Default methods in functional interfaces – consumer with get and andThen(default)
  • Lambda expressions
  • Functional Interfaces
  • Function
  • Predicate
  • Consumer
  • Supplier
  • Biconsumer
  • Streams – how they wotk at processor level
  • Parallel stream – what, when and why
  • Parallel stream – use join and fork
  • Parallel stream, tradeoff and blocking calls in it
  • map vs flatmap
  • stream toMap <String, List<String>> - groupby
  • splitIterator
  • PrimitiveIterator
  • Primitive streams
  • Streams slower than normal for loop then why to use them
  • Parallel vs concurrent gc
  • Stream works internally
  • How Java 8 linked list works, singly or doubly.
  • How reverse iterator available on list if singly Linked list
  • Split iterator - tryAdvance and for each remaining
  • Count char Freq in java 8
  • Predicate default methods
  • View projection vs content projection
  • Map of key, list Java 8
  • Object methods on lambda expression reference
  • Functional Programming

Serialization and Externalization

  • Serialization
  • static and transient
  • SerialVersionUID – static final
  • Extrenalization
  • Methods causing serialization
  • Serializable is marker interface, where is write and read methods defined ?

Java IO

  • ObjectOutput stream
  • Object Input Stream

Java Uncategorized

  • If serializable is marker interface, where are read and write methods defined? Who takes care of these methods.
  • Prime numbers upto a given number
  • Pangram – every char at least once
  • Memory efficient Doubly Linked list
  • Stack using queue
  • Detect loop in linked list in O(n)
  • Count number of set bits in binary of a digit
  • Given list of string – Find count of String starting with a specific prefix
  • If serializable is marker interface, where are read and write methods defined? Who takes care of these methods.
  • Serialization - http://www.benchresources.net/java/serialization-in-java/
  • Copy Constructor versus Cloning
  • Even Copy Constructors Are Not Sufficient
  • Shallow vs Deep Copy
  • https://programmingmitra.blogspot.in/2017/01/Java-cloning-copy-constructor-versus-Object-clone-or-cloning.html
  • https://programmingmitra.blogspot.in/2017/01/java-cloning-why-copy-constructors-are-not-sufficient-or-good.html
  • https://programmingmitra.blogspot.in/2016/11/Java-Cloning-Types-of-Cloning-Shallow-Deep-in-Details-with-Example.html
  • https://dzone.com/articles/shallow-and-deep-java-cloning
  • hashcode uses 31 or prime
    • https://stackoverflow.com/questions/299304/why-does-javas-hashcode-in-string-use-31-as-a-multiplier
    • https://computinglife.wordpress.com/2008/11/20/why-do-hash-functions-use-prime-numbers/
    • http://www.jusfortechies.com/java/core-java/hashcode.php
    • https://srvaroa.github.io/jvm/java/openjdk/biased-locking/2017/01/30/hashCode.html
  • wait vs sleep
    • https://stackoverflow.com/questions/1036754/difference-between-wait-and-sleep
    • https://infinitescript.com/2014/09/difference-between-wait-and-sleep-yield-in-java/
  • Jackson JSON
    • https://dzone.com/articles/jackson-annotations-for-json-part-1-serialization
  • http://stackoverflow.com/questions/17263330/does-calling-a-super-constructor-from-subclasss-constructor-create-object-of-sup
  • http://docs.oracle.com/javase/tutorial/java/IandI/super.html
  • http://stackoverflow.com/questions/16498211/does-creating-an-instance-of-a-child-class-automatically-create-its-super-class
  • http://stackoverflow.com/questions/17877615/how-many-objects-are-created-due-to-inheritance-in-java

Coding

  • Print 2D array as spiral

  • Print as spiral

  • Angular js vs 2 vs 4

    • https://dzone.com/articles/learn-different-about-angular-1-angular-2-amp-angu
    • https://dzone.com/articles/angular-2-vs-angular-4-features-performance
  • openssl version -a
  • servlet_destroy
  • Content Negotiation issue
    • https://spring.io/blog/2013/05/11/content-negotiation-using-spring-mvc
    • https://medium.com/@saishav_io/error-406-while-using-and-email-address-as-a-path-variable-in-spring-boot-8caaefc17c7b

Maven

  • Maven All Commands - http://tutorials.jenkov.com/maven/maven-commands.html
  • mvn dependency:sources
  • mvn clean install
  • mvn clean install -DskipTests
  • mvn dependency:tree > C:\Users\chxk7r\Desktop\temp\dependency-tree.txt

Logging

  • MDC - https://www.baeldung.com/mdc-in-log4j-2-logback

  • Util Code

    • RandomStringUtils.random(length, useLetters, useNumbers);

MicroServices

  • microservices architecture
  • Service Registry and discovery
  • Openshift platform
  • Docker
  • images
  • Load balancer
  • Hystrix – Rate Limit + Circuit Breaker
  • zipkin
  • Sleuth
  • batch

Hibernate

  • https://howtodoinjava.com/hibernate/hibernate-jpa-2-persistence-annotations-tutorial/
  • Why ORM
  • Mapping
  • Inheritance
  • Config xml
  • Call stored procedure
  • States – transient, persistent ,detached
  • criteria
  • Criteria projection

Kafka

  • What is kafka
  • Architecture – Zookeeper, Broker, Topic, Partition, Offset
  • Consumer
  • Properties
  • max.poll.records – default 500
  • compressed.topics
  • linger.ms
  • batch.size
  • Performance improvement by batching
  • Avro as data format
  • Avro schema registry
  • Kafka Sreams
  • measure throughput of a partition for your setup
  • Advance Questions
    • Can we do batch processing in Kafka?
    • Can we stop duplicate reads in Kafka?
    • How load balancing happens?

Spring

  • Circular Dependency - http://www.baeldung.com/circular-dependencies-in-spring
  • Singleton - https://www.geeksforgeeks.org/singleton-class-java/
  • RequestBody and ResponseBody
  • http://www.baeldung.com/spring-request-response-body

Spring REST

  • Rest Template
  • http://www.baeldung.com/rest-template
  • http://www.baeldung.com/how-to-use-resttemplate-with-basic-authentication-in-spring
  • Stateful Stateless Concept
  • https://dzone.com/articles/stateless-session-multi-tenant
  • https://dzone.com/articles/how-to-make-a-stateless-session-less-authenticatio
  • https://nordicapis.com/defining-stateful-vs-stateless-web-services/
  • http://whatis.techtarget.com/definition/stateless-app

JSON

  • http://www.baeldung.com/jackson-object-mapper-tutorial

Web Services

  • web.xml / Deployment descriptor - https://cloud.google.com/appengine/docs/standard/java/config/webxml
  • wsdl
  • xsd
  • jaxb
  • Filter vs Intercepors - http://www.javabench.in/2011/10/java-difference-between-filter-and.html?m=1
  • Soap vs REST - https://stackify.com/soap-vs-rest/amp/
  • Jackson Deserialization - https://github.com/FasterXML/jackson-databind/wiki/Deserialization-Features

Angular

  • JSON obj vs js obj
  • How DI works in angular
  • Lifecycle hooks
  • Routers
  • @NgModule
  • Injector in angular works
  • ngRX store - component, action, reducer, store
  • Pure impure functions
  • Pure impure pipes
  • –prod jit vs –prod –aot
  • Stateful angular
  • Session Store
  • Custom Pipes and declarations
  • JWT on angular side
  • https://www.code-sample.com/2017/08/angular-5-interview-questions-and.html?m=1

Others