Deutsche Bank Java Full Stack Developer Interview Questions and Answers

Builder/Factory Pattern is used to create objects with complex initialization logic.

• Builder Pattern separates the construction of a complex object from its representation.

• Factory Pattern creates objects without specifying the exact class of object that will be created.

• Builder Pattern is often used to create immutable objects with many optional parameters.

• Factory Pattern is used when there is a need to create multiple i...read more

Redux is used in React to manage the application state in a predictable way.

• Centralized state management for React applications

• Predictable state changes with actions and reducers

• Easier debugging and testing of state changes

• Facilitates communication between components

Filter a List using Streams in Java

• Use the filter() method to apply a predicate to each element in the stream

• Use collect() method to convert the stream back to a List

• Example: List<String> names = Arrays.asList("Alice", "Bob", "Charlie"); List<String> filteredNames = names.stream().filter(name -> name.startsWith("A")).collect(Collectors.toList());

Creating an Entity Class in Java

• Define class with @Entity annotation

• Add @Id annotation for primary key

• Include fields with appropriate data types

There are three types of autowiring in Spring: byType, byName, and constructor.

• byType: Spring looks for a bean of the same type and injects it.

• byName: Spring looks for a bean with the same name and injects it.

• constructor: Spring looks for a constructor and injects the arguments.

Lazy fetch loads data only when needed, while eager fetch loads all related data upfront.

• Lazy fetch is more efficient for performance as it only loads data when required.

• Eager fetch can lead to performance issues by loading unnecessary data upfront.

• Lazy fetch is the default behavior in JPA, while eager fetch needs to be explicitly specified.

• Example: Lazy fetch can be used for loading a list of items in a shopping cart ...read more

Transaction management in Hibernate ensures ACID properties for database operations.

• Hibernate provides built-in transaction management support through Session interface.

• Transactions can be managed programmatically using beginTransaction(), commit(), and rollback() methods.

• Hibernate also supports declarative transaction management using annotations like @Transactional.

• Transactions in Hibernate ensure Atomicity, Consiste...read more

Attached entities are actively managed by the persistence context, while detached entities are no longer actively managed.

• Attached entities are being managed by the persistence context and any changes made to them will be automatically synchronized with the database.

• Detached entities are not being managed by the persistence context and changes made to them will not be automatically synchronized with the database.

• Entiti...read more

Creating two beans in Java using Spring framework

• Use @Component annotation to define a bean

• Specify the bean name using @Component("beanName")

• Use @Autowired annotation to inject one bean into another

Sort an Employee HashMap based on keys or values

• Use TreeMap to automatically sort by keys

• Use Comparator to sort by values

• Convert HashMap to List and then sort