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How-to articles, tricks, and solutions about JAVA

Hibernate throws MultipleBagFetchException - cannot simultaneously fetch multiple bags

If you are using Hibernate and you see the error "MultipleBagFetchException: cannot simultaneously fetch multiple bags", it means that you are trying to fetch multiple collections of an entity using a single Hibernate query.

java hibernate jpa one-to-many bag

What are all the different ways to create an object in Java?

In Java, you can create an object in the following ways:

java

Does java.util.List.isEmpty() check if the list itself is null?

No, the isEmpty() method of the java.util.List interface does not check if the list itself is null.

java list

How to calculate the running time of my program?

To calculate the running time of a program in Java, you can use the System.currentTimeMillis() method to get the current time in milliseconds before and after the program runs.

java performance

accessing a variable from another class

To access a variable from another class in Java, you can use the following steps:

java variables

How to perform mouseover function in Selenium WebDriver using Java?

To perform a mouseover (hover) action in Selenium WebDriver using Java, you can use the Actions class.

java selenium selenium-webdriver mouseover

Java 11 package javax.xml.bind does not exist

If you are seeing the error "package javax.xml.bind does not exist" in your Java 11 project, it means that the Java XML Bind (JAXB) API is not included in the classpath.

java jaxb java-11 jakarta-ee

Initializing multiple variables to the same value in Java

In Java, you can initialize multiple variables to the same value in a single statement by separating the variables with a comma.

java initialization variables declaration

Can an int be null in Java?

No, an int data type in Java cannot be null.

java

No Persistence provider for EntityManager named

If you are seeing the error "No Persistence provider for EntityManager named [persistence-unit-name]" in your Java application, it means that the persistence provider (e.g.

java jpa persistence toplink