Roy Tutorials

Conditional Class Spring @ConditionalOnClass and @ConditionalOnMissingClass annotations let @Configuration classes be included based on the presence or absence of specific classes. So @ConditionalOnClass loads a bean only if a certain class is on the class path and @ConditionalOnMissingClass loads a bean only if a certain class is not on the class path. This mechanism does not apply the same way…

Map To List Objects Here I will show you how to convert List of Map objects into List of objects using Java 8’s or later’s Stream API. The List of Map objects can be found as a result of selecting multiple records from database table or any other sources. Then you may need to convert into List of objects to…

Flash Message You will see here how to do flash message management using Python, Flask. Ideally almost every application needs to provide some meaningful message to end user after some activities performed by end users. Such activities may be registration on a site, login, payment, etc. So after each operation whether success or failure most of the time we need…

Conditional On Missing Bean In this tutorial I will create examples on Spring @ConditionalOnMissingBean. Anywhere you define a Spring bean, you can optionally add a condition. Only if the specified condition is satisfied then only bean will be added to the application context. To declare a condition, you can use any of the @Conditional… annotations. The @ConditionalOnMissingBean annotation lets a…

Conditional On Bean I will create examples on Spring @ConditionalOnBean. Anywhere you define a Spring bean, you can optionally add a condition. Only if the specified condition is satisfied then only bean will be added to the application context. To declare a condition, you can use any of the @Conditional… annotations. The @ConditionalOnBean annotation let a bean be included based…

MySQL In this tutorial you will see here how to install MySQL zip archive in Windows operating system. I will download MySQL community version for showing this example. You will also see how to connect to MySQL server using default user root. The advantage of installing zip archive version of MySQL server is that later if you find this server…

QueryForObject, QueryForList, BeanPropertyRowMapper In this post you will see how to select records using queryForObject(), queryForList(), BeanPropertyRowMapper in Spring Boot JdbcTemplate. Spring’s queryForObject() is used to fetch single row from the database. Spring’s queryForList() and BeanPropertyRowMapper are used to fetch multiple rows from the database. So, I will fetch single and multiple rows from the database using Spring JdbcTemplate.

Embeddable zip In this post we will see how to install pip with embeddable zip Python in Windows operating system. In my previous tutorial we have seen how to install embeddable zip Python in Windows operating system. We will refer to my previous tutorial as a Python installation prerequisite before we go further down to the details. Why do you…

Introduction Here I will show you how to install embeddable zip Python in Windows Operating System. Generally most of the time you may execute msi or executable file to install a product in Windows Operating System. This is just a matter of extracting the downloaded archive or zip file and put anywhere according to your choice and let’s start with…

Introduction You will see in this post how to create multiple executable jars using maven build tool. You have seen how to create executable jar using maven build tool. I had created only single executable jar file in previous example but here I will create multiple jars.