MindMap Gallery Java common interview questions
This is a mind map about common Java interview questions, which are very beneficial for candidates. Can help candidates better prepare for interviews, understand industry needs, improve skill levels and enhance competitiveness.
Edited at 2024-02-14 23:16:28Ce calendrier annuel, créé avec EdrawMax, présente une disposition claire et organisée des mois de janvier à décembre. Chaque mois est affiché dans un cadre distinct, montrant les jours de la semaine et les dates correspondantes. Les weekends (samedis et dimanches) sont mis en évidence pour une meilleure visibilité. Ce format est idéal pour la planification et l'organisation des activités tout au long de l'année, offrant une vue d'ensemble rapide et facile à consulter.
This quarterly calendar overview for 2026, created with EdrawMax, presents a structured and colorful layout of the entire year divided into four quarters. Each quarter is displayed in a separate column, showcasing the months within that quarter in a clear grid format. The days of the week are labeled, and each date is marked within its respective cell, allowing for easy identification of dates across the year. This calendar is an excellent tool for long-term planning, providing a comprehensive view of the year at a glance.
This weekly calendar for 2026 is designed using EdrawMax to provide a detailed and organized view of each week, starting from January. The left side features a mini monthly calendar for quick reference, highlighting the current week in yellow. Below it, there's a section for weekly goals to help prioritize tasks. The main area is a time-grid from 6:00 AM to 12:00 AM, divided into half-hour slots, allowing for precise scheduling of daily activities throughout the week. This layout is ideal for managing a busy schedule efficiently.
Ce calendrier annuel, créé avec EdrawMax, présente une disposition claire et organisée des mois de janvier à décembre. Chaque mois est affiché dans un cadre distinct, montrant les jours de la semaine et les dates correspondantes. Les weekends (samedis et dimanches) sont mis en évidence pour une meilleure visibilité. Ce format est idéal pour la planification et l'organisation des activités tout au long de l'année, offrant une vue d'ensemble rapide et facile à consulter.
This quarterly calendar overview for 2026, created with EdrawMax, presents a structured and colorful layout of the entire year divided into four quarters. Each quarter is displayed in a separate column, showcasing the months within that quarter in a clear grid format. The days of the week are labeled, and each date is marked within its respective cell, allowing for easy identification of dates across the year. This calendar is an excellent tool for long-term planning, providing a comprehensive view of the year at a glance.
This weekly calendar for 2026 is designed using EdrawMax to provide a detailed and organized view of each week, starting from January. The left side features a mini monthly calendar for quick reference, highlighting the current week in yellow. Below it, there's a section for weekly goals to help prioritize tasks. The main area is a time-grid from 6:00 AM to 12:00 AM, divided into half-hour slots, allowing for precise scheduling of daily activities throughout the week. This layout is ideal for managing a busy schedule efficiently.
Java common interview questions
Java basics
The difference between object-oriented and process-oriented
Process-oriented is a process-centered programming idea
Advantages: Streamlined, easy to understand and implement
Disadvantages: difficult to deal with complex systems, difficult to reuse and maintain
Object-oriented is an object-centered programming idea
Advantages: easy to deal with complex systems, easy to reuse and maintain
Disadvantages: Difficult to understand and implement
Features of Java
simplicity
Simple syntax, easy to learn and use
object-oriented
Encapsulation, inheritance, polymorphism
platform independence
Runs cross-platform, write once, run anywhere
safety
Strong type checking to avoid illegal access
Robustness
Automatic garbage collection to avoid memory leaks
Java syntax
Variables and data types
Basic data types
Integer, floating point, character, Boolean
Reference data type
Class, interface, array
operator
arithmetic operators
Addition, subtraction, multiplication, division, modulo
Relational operators
Greater than, less than, equal to, not equal to
Logical Operators
AND, OR, NOT, XOR
control structure
Conditional statements
if, else, else if
loop statement
for, while, do while
Java object-oriented
classes and objects
Class definition
Properties and methods
Creation and use of objects
new keyword, access properties and methods
encapsulation
Hide implementation details and provide a public interface
inherit
Subclasses inherit the properties and methods of parent classes
Polymorphism
The same method shows different behaviors in different objects
Java Collections
collection framework
List, Set, Map
Collection implementation
ArrayList, LinkedList, HashSet, TreeSet, HashMap, TreeMap
Java exception handling
Anomaly classification
Runtime exception, non-runtime exception
Exception handling
try, catch, finally
Java multithreading
Thread concept
Thread is the smallest unit of program execution
Thread status
new, ready, running, blocked, dead
Thread synchronization
synchronized, volatile, ReentrantLock
JavaIO
File operations
File, FileInputStream, FileOutputStream
Stream operations
InputStream, OutputStream, Reader, Writer
Java network programming
Socket programming
ServerSocket, Socket
URLs and URIs
URL, URI, URLConnection
Java database programming
JDBC
Connect to the database, execute SQL statements, and process result sets
JavaWeb
Servlet
Servlet life cycle, request and response
JSP
JSP syntax, JSP tags, JSTL
Java framework
Spring
IoC, AOP, Spring MVC
Hibernate
ORM, Hibernate configuration, Hibernate query
MyBatis
MyBatis configuration, MyBatis query
Java design patterns
Singleton pattern
Hungry Man Style, Lazy Man Style
Factory pattern
Simple factory, factory method, abstract factory
Observer pattern
observer, observed, event
strategy pattern
policy, context, client
decorator pattern
decorator, decorator, client
adapter mode
adapter, adaptee, client
proxy mode
Agent, proxy, client
Java performance optimization
Performance analysis tools
JProfiler, YourKit, VisualVM
Performance optimization strategies
Reduce object creation, use thread pools, use cache, reduce database access