10+ Pinion Infotech Services Interview Questions and Answers

The digin pattern implemented for string pool is a technique to reuse string objects to optimize memory usage.

• String pool is a cache of string objects stored in memory.

• When a string is created, it is first checked if it already exists in the pool.

• If it does, a reference to the existing string object is returned instead of creating a new one.

• This helps in reducing memory consumption and improving performance.

• Examples: String s1 = "Hello"; String s2 = "Hello"; Here, s1 and s2 w...read more

Check if a number is even or odd without using mod operator.

• Use bitwise AND operator with 1 to check the last bit of the number.

• If the last bit is 0, the number is even. If it's 1, the number is odd.

• Example: (num & 1) == 0 for even, (num & 1) == 1 for odd.

Hashcode and equals method are related to object comparison in Java.

• Hashcode is used to identify the object and equals method is used to compare two objects.

• If two objects are equal, their hashcode values must be the same.

• If two objects have the same hashcode value, it doesn't necessarily mean that they are equal.

• It is recommended to override both hashcode and equals method when creating custom classes.

HashMap is a data structure that stores key-value pairs and provides constant time complexity for basic operations.

• HashMap uses hashing to store and retrieve elements

• It uses an array of linked lists to handle collisions

• The hash function is used to map the key to an index in the array

• The internal implementation includes methods like put(), get(), and resize()

Program to find distinct characters in a given string sentence

• Create a set to store unique characters

• Iterate through the string and add each character to the set

• Return the set of distinct characters

Java 8 introduced several new features including lambda expressions, streams, and default methods.

• Lambda expressions for functional programming

• Streams for processing large data sets

• Default methods for backward compatibility

• Date and Time API improvements

• Nashorn JavaScript engine

• Parallel array sorting

• Type annotations

• Repeatable annotations

• Optional class for null checks

• Base64 encoding and decoding

• PermGen space replaced with Metaspace

• Improved security with TLS 1.2 enabled by defau...read more

Security to microservices can be achieved through various measures.

• Implementing authentication and authorization mechanisms

• Using SSL/TLS for secure communication

• Implementing rate limiting and throttling to prevent DDoS attacks

• Implementing input validation and output encoding to prevent injection attacks

• Implementing logging and monitoring to detect and respond to security incidents

• Using containerization and orchestration tools like Kubernetes to manage and secure microservices...read more

Apigee gateway is a platform for managing and securing APIs.

• It acts as a mediator between the client and the backend services.

• It provides features like authentication, rate limiting, caching, and analytics.

• It can be deployed on-premises or in the cloud.

• It supports various protocols like REST, SOAP, and GraphQL.

• It helps in API versioning and documentation.

Microservices can be deployed on cloud platforms, containers, or on-premise servers.

• Cloud platforms like AWS, Azure, and Google Cloud provide managed services for deploying microservices.

• Containers like Docker and Kubernetes can be used to deploy and manage microservices.

• On-premise servers can also be used to deploy microservices, but require more maintenance and management.

• The choice of deployment platform depends on factors like scalability, security, and cost.

• For example, ...read more