Java Developer Interview Questions 2026 India

Aap Java Developer interview ke liye prep kar rahe ho, par dimaag mein ek hi tension chal rahi hai: “Spring Boot aayega ya DSA? System design puchenge ya bas OOP? Fresher hu toh salary kitni bolu?” Relax bhai, ye confusion normal hai. India mein 2026 tak Java jobs ka competition aur tight ho gaya hai, especially TCS, Infosys, Wipro, Accenture, Capgemini, Paytm, PhonePe, Razorpay, Swiggy, Zomato jaise companies mein.

Java abhi bhi dead nahi hai. Actually backend roles, enterprise apps, fintech systems, banking software, insurance platforms, large-scale microservices mein Java ka solid demand hai. Freshers ko ₹3.5 LPA se ₹8 LPA tak mil sakta hai, product companies mein ₹10 LPA se ₹18 LPA bhi possible hai. 2-5 years experience wale Java Developers easily ₹8 LPA se ₹25 LPA tak ja sakte hain, agar Spring Boot, SQL, cloud, microservices aur basic system design strong hai.

Is blog mein hum Java Developer interview questions 2026 India ke hisaab se cover karenge, fresher se experienced tak. Tone simple rakhenge, answers bhi interview-friendly honge, jaise tum actual interview room mein bol sakte ho.

Java Developer Interview 2026 India: Companies Kya Expect Kar Rahi Hain?#

Aaj kal interviewer sirf syntax nahi puchta. “Class kya hoti hai?” type questions abhi bhi aate hain, but uske saath practical cheezein bhi check hoti hain.

Companies mainly ye skills dekh rahi hain:

1. Core Java strong hai ya nahi
2. OOP concepts real examples ke saath samajhta hai ya nahi
3. Collections, multithreading, exceptions clear hain ya nahi
4. Spring Boot se REST API bana sakta hai ya nahi
5. SQL queries likh sakta hai ya nahi
6. Git, Maven, Docker ka basic idea hai ya nahi
7. DSA mein arrays, strings, hashmap, recursion handle kar sakta hai ya nahi
8. Project explain kar sakta hai ya sirf resume mein likha hai

Service companies jaise TCS, Infosys, Wipro mein fresher level pe Core Java, OOP, SQL, aptitude, coding basics zyada puchte hain.

Product companies jaise Razorpay, PhonePe, Swiggy, Zomato mein Java ke saath DSA, API design, concurrency, database design, caching, microservices bhi puchte hain.

Freshers Ke Liye Java Developer Interview Questions#

Agar tum fresher ho, toh interviewer pehle yahi check karega ki Java padha hai ya bas resume mein daal diya hai. Yahan se preparation start karo.

1. Java kya hai?

Interview answer:

Java ek object-oriented, platform-independent programming language hai. Iska code pehle bytecode mein compile hota hai, phir JVM us bytecode ko run karta hai. Isliye Java ka famous concept hai “write once, run anywhere”.

Tum add kar sakte ho:

Java ka use backend development, Android apps, enterprise applications, banking systems, web applications aur microservices mein hota hai.

2. JVM, JRE aur JDK mein difference kya hai?

Simple answer:

1. JVM: Java Virtual Machine, bytecode ko run karta hai
2. JRE: Java Runtime Environment, JVM plus libraries deta hai program run karne ke liye
3. JDK: Java Development Kit, JRE plus development tools jaise compiler deta hai

Interview line:

Agar mujhe Java program run karna hai toh JRE enough hai, but agar develop aur compile karna hai toh JDK chahiye.

3. Java platform independent kyun hai?

Java source code directly machine language mein convert nahi hota. Pehle bytecode banta hai, aur ye bytecode kisi bhi system ke JVM pe run ho sakta hai. Isliye Java platform independent hai.

4. OOP concepts kya hain?

OOP ke 4 main pillars:

1. Encapsulation
2. Inheritance
3. Polymorphism
4. Abstraction

Good interview answer:

OOP code ko real-world objects ke form mein structure karta hai. Jaise Employee class ho sakti hai, jisme name, salary, department data aur calculateBonus method ho sakta hai.

5. Encapsulation kya hai?

Encapsulation ka matlab data aur methods ko ek class ke andar bind karna, aur data ko direct access se protect karna.

Example:

Private variables bana ke getter-setter methods se access karna.

Interview line:

Encapsulation se data hiding possible hoti hai aur class ke internal data pe control milta hai.

6. Inheritance kya hai?

Inheritance mein ek class dusri class ke properties aur methods use kar sakti hai.

Example:

Vehicle parent class hai, Car child class hai. Car, Vehicle ke methods jaise startEngine use kar sakti hai.

Benefit:

Code reuse hota hai aur hierarchy maintain hoti hai.

7. Polymorphism kya hai?

Polymorphism ka matlab same method name ka different behavior.

Types:

1. Compile-time polymorphism: Method overloading
2. Runtime polymorphism: Method overriding

Example:

add(int a, int b) aur add(double a, double b) overloading hai.

8. Abstraction kya hai?

Abstraction ka matlab unnecessary details hide karna aur sirf important functionality show karna.

Example:

ATM machine mein user ko bas withdraw, check balance options dikhte hain. Andar transaction kaise process ho raha hai, woh hidden hota hai.

Java mein abstraction achieve hoti hai:

1. Abstract class
2. Interface

Core Java Interview Questions 2026#

Ab thoda level up karte hain. Ye questions fresher aur 1-3 years experience dono ke liye common hain.

9. Abstract class aur interface mein difference kya hai?

Short answer:

Abstract class mein abstract aur non-abstract dono methods ho sakte hain. Interface mein methods mostly abstract hote the, but Java 8 ke baad default aur static methods bhi allowed hain.

Difference:

1. Abstract class extends hoti hai
2. Interface implement hota hai
3. Java mein ek class sirf ek abstract class extend kar sakti hai
4. Ek class multiple interfaces implement kar sakti hai
5. Abstract class mein constructors ho sakte hain
6. Interface mein constructors nahi hote

Interview tip:

Agar classes closely related hain toh abstract class use karo. Agar common behavior define karna hai across unrelated classes, toh interface use karo.

10. Method overloading aur overriding mein difference?

Overloading:

Same class mein same method name, different parameters.

Overriding:

Child class parent class ke method ko apne way mein implement karti hai.

Example interview line:

Overloading compile-time polymorphism hai, overriding runtime polymorphism hai.

11. Constructor kya hota hai?

Constructor ek special method hota hai jo object create hone pe call hota hai. Iska name class ke same hota hai aur return type nahi hota.

Types:

1. Default constructor
2. Parameterized constructor
3. Copy constructor, Java mein built-in nahi hota but manually bana sakte hain

12. Static keyword kya karta hai?

Static member class level pe belong karta hai, object level pe nahi.

Use cases:

1. Static variables shared data ke liye
2. Static methods utility functions ke liye
3. Static blocks class loading time pe execute hote hain

Example:

Math.sqrt() static method hai.

13. Final keyword ka use kya hai?

Final keyword teen jagah use hota hai:

1. Final variable: value change nahi hogi
2. Final method: override nahi hoga
3. Final class: inherit nahi hogi

Example:

String class final hai, isliye koi usko extend nahi kar sakta.

Java Collections Interview Questions#

Java Collections interview ka favourite topic hai. TCS se Razorpay tak, har jagah pucha jaata hai.

14. Collection Framework kya hai?

Java Collection Framework classes aur interfaces ka set hai jo objects ko store, manage aur process karne ke liye use hota hai.

Main interfaces:

1. List
2. Set
3. Queue
4. Map

15. ArrayList aur LinkedList mein difference?

ArrayList:

1. Internal array use karta hai
2. Random access fast hota hai
3. Search faster hota hai
4. Insertion/deletion middle mein slow ho sakta hai

LinkedList:

1. Nodes use karta hai
2. Insertion/deletion fast ho sakta hai
3. Random access slow hota hai
4. Zyada memory use karta hai due to node references

Interview answer:

Agar frequent read operations hain, ArrayList better. Agar frequent insert/delete operations hain, LinkedList consider kar sakte hain.

16. HashMap kaise kaam karta hai?

HashMap key-value pairs store karta hai. Jab hum put karte hain, key ka hashCode calculate hota hai, usse bucket decide hoti hai. Agar same bucket mein multiple entries aayein, equals method se correct key identify hoti hai.

Java 8 ke baad agar bucket mein collisions zyada ho jaate hain, linked list tree structure mein convert ho sakti hai for better performance.

17. HashMap aur Hashtable mein difference?

HashMap:

1. Not synchronized
2. Fast
3. One null key allow karta hai
4. Multiple null values allow karta hai

Hashtable:

1. Synchronized
2. Slower
3. Null key/value allow nahi karta
4. Legacy class hai

18. HashSet duplicate values kaise avoid karta hai?

HashSet internally HashMap use karta hai. Jab object add hota hai, hashCode aur equals method use hote hain duplicate check ke liye.

Agar custom objects HashSet mein store kar rahe ho, toh hashCode aur equals properly override karna important hai.

19. Comparable aur Comparator mein difference?

Comparable:

1. Natural sorting define karta hai
2. compareTo method use hota hai
3. Same class ke andar implement hota hai

Comparator:

1. Custom sorting define karta hai
2. compare method use hota hai
3. Separate class ya lambda se implement kar sakte ho

Example:

Employee ko salary ke basis pe sort karna hai, Comparator use karo. Default name ke basis pe sort karna hai, Comparable use kar sakte ho.

Java Exception Handling Interview Questions#

Exceptions pe interviewer ye check karta hai ki production code likhne ka sense hai ya nahi.

20. Exception kya hota hai?

Exception ek unwanted event hai jo program ke normal flow ko disturb karta hai.

Example:

File not found, divide by zero, null pointer, database connection failure.

21. Checked aur unchecked exceptions mein difference?

Checked exceptions:

Compile time pe check hote hain. Handle karna mandatory hota hai.

Example:

IOException, SQLException.

Unchecked exceptions:

Runtime pe occur hote hain. Handle karna mandatory nahi hota.

Example:

NullPointerException, ArithmeticException, ArrayIndexOutOfBoundsException.

22. throw aur throws mein difference?

throw:

Exception ko explicitly throw karne ke liye use hota hai.

throws:

Method declaration mein batata hai ki ye method exception throw kar sakta hai.

Interview line:

throw actual exception object throw karta hai, throws method signature mein warning deta hai.

23. finally block kab execute hota hai?

Finally block mostly always execute hota hai, chahe exception aaye ya nahi aaye. Usually resource cleanup ke liye use hota hai, jaise file close karna, database connection close karna.

Exception:

Agar System.exit() call ho jaaye, JVM crash ho jaaye, ya power failure ho, toh finally execute nahi hoga.

Multithreading Interview Questions#

Experienced Java roles mein multithreading important hai, especially fintech, payments, trading, food delivery backend jaise domains mein.

24. Thread kya hota hai?

Thread program ka lightweight execution unit hota hai. Ek process ke andar multiple threads run kar sakte hain.

Example:

Food delivery app mein ek thread order place kar raha hai, dusra payment verify kar raha hai, teesra notification send kar raha hai.

25. Thread create kaise karte hain?

Java mein thread create karne ke common ways:

1. Thread class extend karke
2. Runnable interface implement karke
3. Callable interface use karke
4. ExecutorService use karke

Interview tip:

Runnable better hota hai kyunki Java multiple inheritance support nahi karta, aur class kisi aur class ko extend kar sakti hai.

26. synchronized keyword kya karta hai?

Synchronized ek time pe ek hi thread ko critical section access karne deta hai. Isse data inconsistency avoid hoti hai.

Example:

Bank account balance update karte time agar multiple threads same account modify kar rahe hain, synchronized use kar sakte hain.

27. Deadlock kya hota hai?

Deadlock tab hota hai jab do ya zyada threads ek dusre ke resources ka wait karte rehte hain, aur koi bhi proceed nahi karta.

Example:

Thread A lock1 hold karta hai aur lock2 ka wait karta hai. Thread B lock2 hold karta hai aur lock1 ka wait karta hai. Dono stuck.

28. wait, notify aur notifyAll kya karte hain?

Ye methods thread communication ke liye use hote hain.

1. wait: thread ko waiting state mein bhejta hai
2. notify: ek waiting thread ko wake up karta hai
3. notifyAll: sab waiting threads ko wake up karta hai

Ye Object class ke methods hain, Thread class ke nahi.

Spring Boot Interview Questions 2026#

Aaj Java Developer bolke sirf Core Java nahi chalega. Spring Boot almost must-have ban gaya hai.

29. Spring Boot kya hai?

Spring Boot Spring framework ka extension hai jo application development fast aur simple banata hai. Isme auto-configuration, embedded server, starter dependencies jaise features hote hain.

Interview line:

Spring Boot se hum standalone production-ready applications easily bana sakte hain without heavy XML configuration.

30. Spring aur Spring Boot mein difference?

Spring:

Manual configuration zyada hoti hai. XML ya Java config likhna padta hai.

Spring Boot:

Auto-configuration deta hai, embedded Tomcat hota hai, starter dependencies hoti hain, application quickly start ho jaata hai.

31. @SpringBootApplication annotation kya karta hai?

Ye teen annotations ka combination hai:

1. @Configuration
2. @EnableAutoConfiguration
3. @ComponentScan

Isse Spring Boot app auto configure hoti hai aur components scan hote hain.

32. @RestController aur @Controller mein difference?

@Controller:

Usually web pages return karne ke liye use hota hai.

@RestController:

REST APIs ke liye use hota hai. Ye @Controller plus @ResponseBody ka combination hai.

33. @GetMapping, @PostMapping, @PutMapping, @DeleteMapping kya hain?

Ye HTTP methods handle karte hain:

1. @GetMapping: data fetch karna
2. @PostMapping: new data create karna
3. @PutMapping: existing data update karna
4. @DeleteMapping: data delete karna

Example:

E-commerce app mein product list GET se aayegi, new order POST se create hoga.

34. Dependency Injection kya hai?

Dependency Injection ka matlab object apni dependency khud create nahi karta, Spring container usko provide karta hai.

Benefit:

Code loosely coupled hota hai, testing easy hoti hai, maintainability improve hoti hai.

Example:

OrderService ko PaymentService chahiye. OrderService khud new PaymentService() nahi karega, Spring inject karega.

35. @Autowired kya karta hai?

@Autowired Spring ko batata hai ki dependency automatically inject karni hai.

Best practice:

Constructor injection use karo instead of field injection, kyunki testing easy hoti hai aur dependencies clear dikhti hain.

36. Spring Boot mein application.properties ka use?

Ye configuration file hoti hai.

Isme likh sakte hain:

1. Server port
2. Database URL
3. Username password
4. Logging config
5. Custom application properties

Example:

server.port=8081

SQL And Database Questions For Java Developers#

Java backend role mein SQL ignore mat karna. Bahut log yahin fail hote hain.

37. Primary key aur foreign key mein difference?

Primary key:

Table mein record ko uniquely identify karti hai. Null nahi ho sakti.

Foreign key:

Ek table ko dusre table se connect karti hai. Ye parent table ki primary key ko refer karti hai.

38. JOIN kya hota hai?

JOIN multiple tables se related data fetch karne ke liye use hota hai.

Common joins:

1. INNER JOIN
2. LEFT JOIN
3. RIGHT JOIN
4. FULL JOIN

Example:

Employee table aur Department table ko department_id se join kar sakte hain.

39. Index kya hota hai?

Index database search ko fast banata hai. Jaise book ka index pages quickly find karne mein help karta hai.

But dhyaan:

Index read queries fast karta hai, but insert/update/delete thoda slow kar sakta hai kyunki index bhi update hota hai.

40. Normalization kya hai?

Normalization database design technique hai jisme data redundancy reduce karte hain aur data consistency improve karte hain.

Common normal forms:

1. 1NF
2. 2NF
3. 3NF

Interview mein usually 3NF tak enough hota hai.

DSA Questions Java Developer Interviews Mein#

Fresher ho ya 2 years experienced, DSA ka basic toh aana hi chahiye. Product companies mein DSA heavy ho sakta hai.

41. Java mein string reverse kaise karoge?

Simple ways:

1. StringBuilder reverse method
2. Loop use karke
3. Recursion se

Interview answer:

Production mein simple reverse ke liye StringBuilder ka reverse method use karna clean hai.

42. Array mein duplicate elements kaise find karoge?

Approaches:

1. Nested loop, O(n²)
2. HashSet use karke, O(n)
3. Sorting karke, O(n log n)

Best practical answer:

HashSet use karunga, agar element already present hai toh duplicate hai.

43. HashMap use karke character frequency kaise count karoge?

Logic:

1. String ke har character pe loop
2. Map mein character key rakho
3. Count increment karo
4. Final map frequency show karega

Example:

“java” mein j:1, a:2, v:1.

44. Two sum problem kaise solve karoge?

Problem:

Array diya hai aur target sum diya hai. Do numbers find karo jinka sum target ho.

Efficient approach:

HashMap use karo. Current number ke liye complement target - current check karo. Agar map mein complement hai, answer mil gaya.

Time complexity:

O(n)

45. Palindrome string kaise check karoge?

Two pointer approach:

1. Left pointer start pe
2. Right pointer end pe
3. Dono characters compare karo
4. Match hai toh move inward
5. Mismatch hai toh false

Time complexity O(n), space O(1).

Experienced Java Developer Interview Questions#

Agar tum 2-6 years experience wale ho, toh interviewer practical project-based questions puchta hai. Yahan fake experience pakda jaata hai.

46. Microservices kya hain?

Microservices architecture mein application ko chhoti independent services mein divide karte hain. Har service ek specific business function handle karti hai.

Example:

Food delivery app mein:

1. User service
2. Restaurant service
3. Order service
4. Payment service
5. Notification service
6. Delivery tracking service

Swiggy ya Zomato type systems mein aise modules alag services ho sakte hain.

47. Monolith aur microservices mein difference?

Monolith:

Pura application ek single codebase aur deployment unit hota hai.

Microservices:

Application multiple independent services mein split hoti hai.

Trade-off:

Microservices flexible hain, but complexity bhi badhti hai, jaise service communication, monitoring, deployment, data consistency.

48. REST API design karte time kya dhyaan rakhoge?

Important points:

1. Proper HTTP methods use karna
2. Meaningful endpoint names
3. Status codes correct use karna
4. Request validation
5. Error response clear rakhna
6. Pagination for large data
7. Authentication and authorization
8. Versioning if needed

Example:

GET /users/101
POST /orders
PUT /products/55
DELETE /cart/items/10

49. HTTP status codes ka use?

Common codes:

1. 200 OK: success
2. 201 Created: new resource created
3. 400 Bad Request: invalid input
4. 401 Unauthorized: login required
5. 403 Forbidden: permission nahi hai
6. 404 Not Found: resource nahi mila
7. 500 Internal Server Error: server issue

50. JWT kya hota hai?

JWT ka full form JSON Web Token hai. Ye authentication ke liye use hota hai. User login ke baad server token generate karta hai, client har request ke saath token send karta hai.

JWT usually stateless authentication mein use hota hai.

51. Caching kya hoti hai?

Caching ka matlab frequently used data ko fast storage mein rakhna, taaki baar-baar database hit na karna pade.

Example:

Product catalog, user session, city list, restaurant menu.

Tools:

1. Redis
2. Memcached
3. In-memory cache

PhonePe ya Paytm jaise payment apps mein cache carefully use hota hai because data consistency important hoti hai.

52. Message queue kya hota hai?

Message queue async communication ke liye use hota hai.

Example:

Order place hote hi payment, invoice, notification sab same time pe sync call nahi karna. Order service message queue mein event publish karegi, baaki services consume karengi.

Common tools:

1. Kafka
2. RabbitMQ
3. ActiveMQ

53. Kafka ka basic use kya hai?

Kafka high-throughput messaging platform hai. Large-scale event streaming ke liye use hota hai.

Use cases:

1. Order events
2. Payment status updates
3. Logs processing
4. Notification pipeline
5. Real-time analytics

Java 8 Interview Questions#

Java 8 abhi bhi interviews ka hero topic hai. Ignore mat karna.

54. Lambda expression kya hai?

Lambda expression anonymous function jaisa hota hai. Ye functional programming style support karta hai.

Example:

List sorting ya filtering mein lambda use hota hai.

Interview line:

Lambda code ko concise banata hai, especially functional interfaces ke saath.

55. Functional interface kya hota hai?

Functional interface mein sirf ek abstract method hota hai.

Example:

1. Runnable
2. Callable
3. Comparator
4. Predicate
5. Function

@FunctionalInterface annotation optional hai but recommended hai.

56. Stream API kya hai?

Stream API collection data ko process karne ke liye use hoti hai in functional style.

Common operations:

1. filter
2. map
3. sorted
4. collect
5. reduce
6. forEach

Example:

Employees list mein se salary ₹10 LPA se zyada wale employees filter karna.

57. map aur flatMap mein difference?

map:

Ek input ko ek output mein convert karta hai.

flatMap:

Nested structure ko flatten karta hai.

Example:

List of lists ko single list banana hai, flatMap use karo.

58. Optional class kya hai?

Optional null values handle karne ka safer way hai. Isse NullPointerException avoid karne mein help milti hai.

But dhyaan:

Optional ko blindly har jagah use mat karo, mostly return types mein use karo.

HR Interview Questions For Java Developers#

Technical clear ho gaya, ab HR round mein bhi smart answer chahiye. Yahan overconfidence ya desperate tone dono avoid karo.

59. Tell me about yourself.

Structure:

1. Name and education
2. Java skills
3. Projects or experience
4. Internship/job exposure
5. Role interest

Sample:

“Hi, I am Rahul, B.Tech CSE graduate from Pune. I have good understanding of Core Java, OOP, Collections, SQL and Spring Boot basics. I built a student management REST API using Spring Boot and MySQL. I am looking for a Java Developer role where I can work on backend development and improve my production-level skills.”

60. Why Java Developer role?

Answer:

“Java has strong usage in backend systems, banking, payments and enterprise applications. I enjoy building APIs and solving backend logic. That is why I want to start or grow my career as a Java Developer.”

61. Expected salary kya bolna chahiye?

Freshers ke liye:

Agar service company hai, ₹3.5 LPA to ₹6 LPA common hai. Good product startup mein ₹8 LPA to ₹12 LPA bhi possible hai.

Answer:

“As a fresher, my priority is learning and the right role. Based on the market and my skills, I am expecting around ₹5 LPA to ₹7 LPA, but I am open to discussion.”

2-3 years experience:

Agar current ₹6 LPA hai, toh ₹9 LPA to ₹13 LPA reasonable ho sakta hai, depending skills.

Answer:

“Based on my experience in Java, Spring Boot, SQL and backend development, I am expecting around ₹12 LPA. But I am flexible for the right opportunity and growth.”

62. Notice period kitna hai?

Simple honest answer do. Fake mat bolo.

Example:

“My official notice period is 60 days, but I can discuss with my manager and try for early release.”

63. Why should we hire you?

Answer:

“I have strong basics in Java, OOP, Collections, SQL and Spring Boot. I have built practical projects and I am comfortable learning new tools quickly. I may not know everything, but I can debug, learn and deliver with consistency.”

Java Developer Resume Tips For 2026#

Interview questions ki prep ke saath resume bhi strong hona chahiye. Bahut baar problem interview prep nahi, resume shortlisting hoti hai.

ATS software pehle resume scan karta hai. Agar resume mein right keywords nahi hain, toh human recruiter tak pahunchne se pehle reject ho sakta hai.

Resume mein ye keywords zaroor add karo

Agar genuinely aata hai toh:

1. Java
2. Core Java
3. OOP
4. Collections
5. Exception Handling
6. Multithreading
7. Spring Boot
8. REST API
9. MySQL
10. PostgreSQL
11. Hibernate
12. JPA
13. Maven
14. Git
15. Docker
16. Microservices
17. JUnit
18. Mockito
19. Kafka
20. Redis

Project description kaise likho?

Bad line:

“Made Java project.”

Good line:

“Built a Spring Boot REST API for employee management with CRUD operations, MySQL database, input validation and exception handling.”

Even better:

“Developed employee management backend using Spring Boot, MySQL and JPA. Implemented CRUD APIs, global exception handling, pagination and basic unit tests using JUnit.”

Fresher projects jo resume mein strong lagte hain

1. Employee Management System
2. Student Result Management System
3. Online Food Ordering Backend
4. Banking Transaction API
5. Expense Tracker
6. Library Management System
7. Job Portal Backend
8. E-commerce Product API

Bas GitHub pe daal dena. Interviewer bole “code dikhao”, toh panic nahi hona chahiye.

7-Day Java Interview Prep Plan#

Agar interview next week hai, toh ye plan follow kar.

Day 1: Core Java

Cover:

1. JVM, JDK, JRE
2. OOP
3. Static, final
4. Constructor
5. String

Day 2: Collections

Cover:

1. ArrayList
2. LinkedList
3. HashMap
4. HashSet
5. Comparable, Comparator

Day 3: Exception + Multithreading

Cover:

1. Checked vs unchecked
2. throw vs throws
3. finally
4. Thread lifecycle
5. synchronized
6. deadlock

Day 4: Spring Boot

Cover:

1. REST API
2. Annotations
3. Dependency Injection
4. application.properties
5. Controller-Service-Repository flow

Day 5: SQL

Cover:

1. Joins
2. Group by
3. Index
4. Primary key, foreign key
5. Basic query practice

Day 6: DSA

Cover:

1. String reverse
2. Palindrome
3. Duplicate in array
4. Two sum
5. Character frequency
6. Sorting basics

Day 7: Mock Interview + Resume

Do:

1. Self-introduction practice
2. Project explanation
3. HR answers
4. Resume keyword check
5. GitHub links verify
6. LinkedIn update

Common Mistakes Jo Java Interview Mein Reject Karwa Deti Hain#

Bhai, ye mistakes avoid karna. Interviewer ko impress karne se pehle irritate mat karo.

1. Resume mein Spring Boot likha, but REST API explain nahi kar paaye
2. HashMap ka internal working nahi pata
3. OOP definitions ratta maar ke bole, example nahi diya
4. Project khud nahi banaya, YouTube se copy kiya
5. SQL joins practice nahi kiye
6. Java 8 Stream API completely skip kar diya
7. Expected salary unrealistic bol diya
8. GitHub empty hai, but resume mein “hands-on projects” likha hai
9. Communication mein clarity nahi hai
10. “I know everything” attitude dikha diya

Final Checklist Before Java Developer Interview#

Interview se ek din pehle ye checklist dekh lena:

1. Resume PDF format mein ready
2. Resume file name professional: Rahul_Java_Developer_Resume.pdf
3. GitHub projects working
4. LinkedIn updated
5. Core Java quick revision
6. Top 20 SQL queries revise
7. Spring Boot project flow explain karna aata hai
8. Self-introduction 60 seconds mein ready
9. Expected salary range clear
10. Company ke baare mein basic research

Agar TCS, Infosys, Wipro jaise service companies ke liye ja rahe ho, toh basics clean rakho. Agar Razorpay, PhonePe, Swiggy, Zomato, Paytm jaise product companies target kar rahe ho, toh DSA plus backend design plus project depth strong rakho.

Java Developer interview crack karna impossible nahi hai. Bas random YouTube videos dekhne ke bajaye structured prep karo. Core Java, Collections, Spring Boot, SQL, DSA aur project explanation, ye 6 cheezein pakki kar lo, chances kaafi improve ho jaate hain.

Aur ek last senior bhai advice: agar callback hi nahi aa raha, toh problem tumhari skills nahi, resume bhi ho sakta hai. ATS-friendly resume nahi hua toh recruiter tak pahunchne se pehle reject ho jaoge.

Apna resume free mein check karo yahan: JobRise Free ATS Checker