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77 core java developer interview questions shared by candidates

While the interview questions were basic, these were not the answers you might be remembering or having only one correct answer. HTTP Codes, RestAPI design, database query on tree and recursion, Code analysis on switch case, etc and other past experience questions.
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Software Engineer Core Java

Interviewed at Syndigo

3.8★
Jun 27, 2023

While the interview questions were basic, these were not the answers you might be remembering or having only one correct answer. HTTP Codes, RestAPI design, database query on tree and recursion, Code analysis on switch case, etc and other past experience questions.

1. Tell me something about you? 2. Tell some your skills ? 3. Explain internal working of Treemap? 4. following above question , What is self balanced tree ,& Binery tree? explain how it is work and how it is used in TreeMap. 5.Why we need Callable interface? tell something about Future? 6. where do you used the multithreading in your project? why do you used it? 2nd round(Manager) 1. we have map ,and we have put these values , how many element would be there in map? 2.How you can access service from component?(angular2+) 3. how you can call any api from service?(angular2+) 4. what is payload? 5. Full form of JSON and Rest? 6. give some example of JSON? 7. IS it important to put all key and value inside "" this mark?(JSON) 8. Do you remeber any jar that convert the given object into Json? 9.how you can retrieve back the key of given value from map if you forget the key? 10. what collection will you use to cache all the data of Employee table? 11. how you will create REST API in Spring rest/Spring boot? 12. what happen if two different developer use the same END point url while creating the REST api? 13. sql - suppose you have employee table , any you have to find out how many male and female are working. than write sql to find it. 14. sql. now find out male and female count based on city that working on company?
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Core Java Developer

Interviewed at UBS

3.7★
Aug 20, 2018

1. Tell me something about you? 2. Tell some your skills ? 3. Explain internal working of Treemap? 4. following above question , What is self balanced tree ,& Binery tree? explain how it is work and how it is used in TreeMap. 5.Why we need Callable interface? tell something about Future? 6. where do you used the multithreading in your project? why do you used it? 2nd round(Manager) 1. we have map ,and we have put these values , how many element would be there in map? 2.How you can access service from component?(angular2+) 3. how you can call any api from service?(angular2+) 4. what is payload? 5. Full form of JSON and Rest? 6. give some example of JSON? 7. IS it important to put all key and value inside "" this mark?(JSON) 8. Do you remeber any jar that convert the given object into Json? 9.how you can retrieve back the key of given value from map if you forget the key? 10. what collection will you use to cache all the data of Employee table? 11. how you will create REST API in Spring rest/Spring boot? 12. what happen if two different developer use the same END point url while creating the REST api? 13. sql - suppose you have employee table , any you have to find out how many male and female are working. than write sql to find it. 14. sql. now find out male and female count based on city that working on company?

1st round they give a 2 test 1st one is Aptitude test(multi-threading,collection,etc) 2nd is logical test (no Option) 2nd round they ask to write the code of Q1. Anagram two String without using Array.sort method. Q2. Armstrong number Q3. producer-consumer problem using multi-threading in java Q4. Star pattern in java Q5. Performer in Array without using ArrayList Method like (add,delete,remove).you have to write the own method to add,delete&remove in array 3rd round they ask logical Question base on code that you write in 2nd round 4th round they ask you about your self and family
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Core Java Developer

Interviewed at Xalted Information Systems

3.7★
Dec 11, 2019

1st round they give a 2 test 1st one is Aptitude test(multi-threading,collection,etc) 2nd is logical test (no Option) 2nd round they ask to write the code of Q1. Anagram two String without using Array.sort method. Q2. Armstrong number Q3. producer-consumer problem using multi-threading in java Q4. Star pattern in java Q5. Performer in Array without using ArrayList Method like (add,delete,remove).you have to write the own method to add,delete&remove in array 3rd round they ask logical Question base on code that you write in 2nd round 4th round they ask you about your self and family

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