Ups Logistics Senior Application Developer Interview Questions, Process, and Tips

When passing an object as the key in a map, extra functionality needs to be implemented to ensure proper hashing and equality comparison.

• Override hashCode() method to generate a unique hash code for the object

• Override equals() method to compare the objects for equality

• Implement Comparable interface if custom sorting is required

Implementing Spring security involves configuring security settings in the Spring application.

• Add Spring Security dependency in pom.xml

• Configure security settings in SecurityConfig class

• Define user roles and permissions

• Use annotations like @EnableWebSecurity and @Secured

Functional interfaces can have only one abstract method, but can have multiple static and default methods.

• Functional interfaces in Java can have only one abstract method, but can have multiple static and default methods.

• Static methods in functional interfaces can be called using the interface name itself.

• Default methods provide a default implementation in the interface itself.

• Example: java.util.function.Function is a f...read more

Use Comparator interface to sort objects by fields in Java.

• Implement Comparator interface and override compare method

• Use Collections.sort() method with custom Comparator

• Example: Sorting a list of Person objects by age field

Use synchronization mechanisms like barriers or join to aggregate parallel threads

• Use synchronization mechanisms like barriers or join to wait for all threads to complete before proceeding

• Implement a barrier that blocks all threads until they all reach a certain point in the code

• Use a join operation to wait for all threads to finish before continuing execution