Understanding JPA: The Java Persistence API Explained

JPA stands for Java Persistence API. It is a specification for accessing, managing, and persisting data between Java objects and…

Why I/O Operations Are Expensive: Understanding the Factors and Solutions

I/O operations are often considered expensive in computer systems due to several factors: Hardware limitations: I/O operations involve interacting with…

10 Effective Strategies to Enhance I/O Operations for Improved Performance

To improve I/O operations in your Java programs, you can consider the following strategies: Use buffering: Utilize buffering mechanisms such…

Java I/O Operations: A Comprehensive Guide for Efficient Data Handling

In Java, input/output (I/O) operations are used to interact with external resources such as files, network sockets, and user input/output.…

hibernate.cfg.xml location in maven project

[solved] hibernate.cfg.xml location in maven project

Hello guys, In this article, I will describe where you will keep the hibernate.cfg.xml file in your project directory. It’s…

java.lang.NoClassDefFoundError

How can I solve “java.lang.NoClassDefFoundError”

Hello guys, today we will show a common error while working on java based projects. This error is “java.lang.NoClassDefFoundError“. We…

web.xml File Location in Dynamic WebApp in Eclipse IDE

Hello friends, Sometimes when we are working with webapp in Eclipse, may not create the web.xml file by default. As…

How to Handle Error in Web.xml for Java Web Applications

Hello friends, Today I will show you how to handle the error or display customized error messages in JSP and…

How to send redirect from Java Servlet

Hello friends, Today I am going to show you how to send redirect from Java Servlet. In this example, we…

How to Apply CSS in out.println() method in JSP and Servlet

Hello friends, Today I am going to show you how to apply CSS in the out.println() method using JSP and…

How to display a list of objects in JSP through Servlet

Hello friends, Today I am going to show you how to display a list of objects using JSP and servlet.…

How to show data from MySQL database using JSP and Servlet

Hello friends, Today I am going to show you how to display data from the MySQL database using JSP and…

How to insert data in MySQL database using JSP and Servlet

Hello friends, Today I am going to show you how to insert data in the MySQL database using JSP and…

How to configure h2 database in spring boot

Hello, Today we will discuss how to configure the h2 database in the spring boot application properly. Follow the below…

How to Build a Web Scraper in Java

Hello, Today we are going to build a web scraper. Although All of you know the term, I just want…

[solved] caused by: org.hibernate.PersistentObjectException: detached entity passed to persist:

The error looks like org.hibernate.PersistentObjectException: detached entity passed to persist: example.forms.InvoiceItem at org.hibernate.event.def.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:127) at…