Category Archives for Java

In Java, How Can A Float Be Printed With Two Decimal Places?

To print a float with 2 decimal places in Java, you can use the printf method of the System.out object. Here is an example: float number = 3.14159f; System.out.printf("%.2f", number); The %f is the placeholder for a floating-point number, and the .2 before the f specifies the number of decimal places to display.

Continue reading

What Is The Purpose Of Using A Serialversionuid In Java?

In Java, serialVersionUID is a unique identifier for a serialized class. It is used during the process of serialization and deserialization to verify that the sender and receiver of a serialized object have loaded classes for that object that are compatible with respect to serialization. When an object is serialized (converted into a byte stream), […]

Continue reading

How Can You Use The Simple JSON Library To Read A JSON File Into Java?

To read a JSON file into Java using the Simple JSON library, you can follow these steps: Include the Simple JSON library in your project. You can download the JAR file from the official website (https://github.com/fangyidong/json-simple) or use a dependency management tool like Maven. Create a JSON parser to parse the JSON file. You can […]

Continue reading

Mockito : How To Verify Method Was Called On An Object Created Within A Method?

To verify that a method was called on an object created within a method, you can use Mockito’s @Captor annotation along with ArgumentCaptor. Here’s an example: import org.junit.Test; import org.junit.runner.RunWith; import org.mockito.ArgumentCaptor; import org.mockito.Captor; import org.mockito.Mock; import org.mockito.junit.MockitoJUnitRunner; import static org.mockito.Mockito.verify; @RunWith(MockitoJUnitRunner.class) public class ExampleTest { @Mock private Dependency dependency; @Captor private ArgumentCaptor<SomeObject> objectCaptor; @Test […]

Continue reading

What Causes A Java.lang.arrayindexoutofboundsexception And How Do I Prevent It?

A java.lang.ArrayIndexOutOfBoundsException occurs when you try to access an array element with an index that is outside the valid range of indices for that array. More specifically, this exception is thrown when: Trying to access or modify an element using a negative index. Attempting to access or modify an element using an index greater than […]

Continue reading

Org.hibernate.hibernateexception: Access To DialectResolutionInfo Cannot Be Null When ‘hibernate.dialect’ Not Set

The exception "HibernateException: Access to DialectResolutionInfo cannot be null when ‘hibernate.dialect’ not set" occurs when you are using Hibernate and you have not set the ‘hibernate.dialect’ property in your configuration file. The Hibernate dialect is responsible for translating Hibernate’s HQL (Hibernate Query Language) into the SQL dialect of the underlying database. It is mandatory to […]

Continue reading

Spring Boot 2.6.0 / Spring Fox 3 – Failed To Start Bean ‘documentationpluginsbootstrapper’

The error message "Failed to start bean ‘documentationPluginsBootstrapper’" usually indicates a problem with the Swagger/OpenAPI documentation generation in a Spring Boot application using Springfox 3.x. To resolve this issue, you can try the following steps: Check your pom.xml or build.gradle file to ensure that you have the correct dependencies for Springfox 3.x. Make sure that […]

Continue reading

In Java, What Is The Method To Add One Day To A Date?

To increment a date by one day in Java, you can use the Calendar class or the LocalDate class from the java.util package. Using Calendar: import java.util.Calendar; public class Main { public static void main(String[] args) { // Create a Calendar instance Calendar calendar = Calendar.getInstance(); // Increment the date by one day calendar.add(Calendar.DAY_OF_YEAR, 1); […]

Continue reading

Web Server Failed To Start. Port 8080 Was Already In Use. Spring Boot Microservice

When you see the error message "Web server failed to start. Port 8080 was already in use" in a Spring Boot microservice, it means that another application or process is already using port 8080 on your machine. To resolve this issue, you can try the following: Find and kill the process using port 8080: In […]

Continue reading

In Java, How Can I Obtain The Current Date And Time In UTC Or GMT?

To get the current date and time in UTC or GMT, you can use the java.util.Calendar class or the newer java.time package introduced in Java 8. Using java.util.Calendar: import java.util.Calendar; import java.util.TimeZone; Calendar calendar = Calendar.getInstance(TimeZone.getTimeZone("UTC")); System.out.println(calendar.getTime()); // current date and time in UTC Using java.time: import java.time.LocalDateTime; import java.time.ZoneId; import java.time.ZonedDateTime; LocalDateTime now = […]

Continue reading
1 2 3 10