Biz4Solutions Interview Questions, Process, and Tips

The string constant pool is a special memory area in Java where string literals are stored.

• String constant pool is a part of the heap memory.

• It is used to optimize memory usage by reusing string literals.

• String objects created using the same literal share the same memory location.

• String constant pool can be accessed using the intern() method.

• Example: String str1 = "Hello"; String str2 = "Hello"; str1 and str2 point to

I would rate myself at java as an 8 out of 10.

• I have extensive experience in Java programming.

• I have successfully completed multiple Java projects.

• I am familiar with various Java frameworks and libraries.

• I continuously update my knowledge and skills in Java.

• I am confident in my ability to solve complex problems using Java.

s1 stores the string 'hello' in the stack memory, while s2 stores a new string object with the same value in the heap memory.

• s1 is a reference variable that stores the memory address of the string 'hello' in the stack memory.

• s2 is a reference variable that stores the memory address of a new string object created in the heap memory.

• The string 'hello' is stored in the heap memory because it was created using the 'new' ke

I have used Java version 8 and SpringBoot version 2.4.2.

• I have experience working with Java 8 and SpringBoot 2.4.2.

• I am familiar with the features and functionalities of Java 8 and SpringBoot 2.4.2.

• I have developed applications using Java 8 and SpringBoot 2.4.2.

• I have utilized the latest enhancements and improvements provided by Java 8 and SpringBoot 2.4.2.

Java program to filter out prime numbers and print composite numbers from 1 to 100.

• Iterate through numbers 1 to 100

• Check if each number is prime or composite

• Print the composite numbers

A bean in Spring is a Java object that is instantiated, assembled, and managed by the Spring IoC container.

• Beans are the basic building blocks of a Spring application.

• They are defined in the Spring configuration file or using annotations.

• Beans are managed by the Spring IoC container, which handles their lifecycle and dependencies.

• Beans can be singleton, prototype, or scoped.

• Dependency injection is used to wire beans to...read more

RestController is a class in Spring Boot that combines @Controller and @ResponseBody annotations to simplify RESTful web service development.

• RestController is used to create RESTful web services in Spring Boot.

• It is a specialized version of the @Controller annotation.

• It combines the @Controller and @ResponseBody annotations.

• The @ResponseBody annotation is used to bind the method return value to the web response body.

• It...read more

The @Component and @Service annotations in Spring Boot are used to define beans, but @Service is a specialization of @Component.

• Both @Component and @Service annotations are used to define beans in Spring Boot.

• @Service is a specialization of @Component and is used to indicate that a class is a service component.

• The @Service annotation is typically used for classes that perform business logic or provide services.

• The @Com...read more

A Java function to determine if a given number is divisible by 3, 5, or 15.

• Use the modulo operator (%) to check if the number is divisible by 3, 5, or 15.

• If the number is divisible by 3, print 3.

• If the number is divisible by 5, print 5.

• If the number is divisible by 15, print 15.

• If none of the above conditions are met, do not print anything.

The flow of a Spring Boot API involves handling HTTP requests, routing them to appropriate controllers, processing the requests, and returning responses.

• Spring Boot API receives HTTP requests from clients

• The requests are routed to appropriate controllers based on the defined endpoints

• Controllers process the requests by invoking appropriate services or repositories

• Services handle the business logic and interact with rep...read more

Java 8 program to flatten a nested list into a single list.

• Use flatMap() method to flatten the nested list.

• Convert the nested list to a stream and use flatMap() to flatten it.

• Collect the flattened stream into a list using the Collectors.toList() method.

Sorts a list of strings based on the second character in each string.

• Use the `Comparator.comparing` method to specify the key for sorting.

• Access the second character of a string using the `charAt` method.

• Use the `Collections.sort` method to sort the list.

Java 8 Stream to get average, minimum, maximum from List of BigDecimal or Integer.

• Use the stream() method on the List to create a Stream

• Use the mapToDouble() method to convert the elements to double values

• Use the average(), min(), and max() methods to get the desired values

• Use the getAsDouble() method to retrieve the result as a double value

A Consumer function for String in Java 8.

• Use the Consumer functional interface from the java.util.function package.

• Implement the accept() method to perform the desired operation on the input string.

• Example: Consumer consumer = (str) -> System.out.println(str.toUpperCase());

We use Java 11 and Spring Boot 2.4.2 in our project.

• Java 11 is the latest LTS version of Java, providing improved performance and security.

• Spring Boot 2.4.2 is a stable release with bug fixes and new features.

• Using the latest versions ensures compatibility with the latest libraries and frameworks.

• Java 11 example: java -version

• Spring Boot 2.4.2 example: spring --version

To retrieve only names from a table, you can use a SELECT query with the appropriate column name.

• Use the SELECT statement to specify the column(s) you want to retrieve.

• Specify the name column in the SELECT clause to retrieve only names.

• Use the FROM clause to specify the table from which you want to retrieve the names.

Server-side validation without third-party library using core Java

• Use regular expressions for pattern matching

• Implement custom validation logic using core Java classes

• Leverage Java's built-in exception handling for error handling

To ensure that the bug fix does not break existing functionality, thorough testing and quality assurance processes should be followed.

• Perform unit testing to verify that the bug fix works as expected and does not introduce new issues.

• Conduct integration testing to ensure that the bug fix does not cause any conflicts or compatibility issues with other components.

• Execute regression testing to validate that the bug fix do...read more

The functional interface mostly used in Java 8 is the java.util.function package.

• The most commonly used functional interfaces in Java 8 are Predicate, Consumer, Function, and Supplier.

• Predicate is used for boolean-valued functions of one argument.

• Consumer is used for operations that take in one argument and return no result.

• Function is used for functions that accept one argument and produce a result.

• Supplier is used fo...read more