One thing is for certain, the OS wars between developers is not a topic that is going away anytime soon. People can be very passionate about the OS they use. Windows has been the dominant OS for a long long time. I used to be a bing Windows user. But not anymore. Like the maid, […]Continue reading
Spring Boot makes it extremely convenient for programmers to quickly develop Spring applications using an in-memory database, such as H2, HSQLDB, and Derby. These databases are lightweight, easy to use, and emulates other RDBMS with the help of JPA and Hibernate. Obviously, they don’t provide persistent storage; but they a fast way to test persistent functions […]Continue reading
A real common task is to display a list of objects fetched from the database in a HTML table on a webpage. Thymeleaf has a handy tag which allows us to iterate over a list of objects, and generate HTML code to display a table row for each object. The HTML generated really does not “need” […]Continue reading
When Autowiring Spring Beans, a common exception is a BeanCreationException. This means that Spring found a bean to create, but was unable to fulfill the dependencies needed to create this this Spring bean. Here is an example of a BeanCreationException: BeanCreationException Exception in thread “main” org.springframework.beans.factory.BeanCreationException: Error creating bean with name ‘helloController’: Injection of autowired […]Continue reading
When Autowiring Spring Beans, a common error is to see a NoSuchBeanDefinitionException. Here is an example of the NoSuchBeanDefinitionException you may see thrown by the Spring context: NoSuchBeanDefinitionException Exception in thread “main” org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [guru.springframework.controllers.HelloController] is defined at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:372) at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:332) at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1060) By default, Spring will Autowire beans by type. You […]Continue reading
At the heart of the Spring Framework is its support of dependency injection through its Inversion of Control container. In this video, I look at using some of the advanced autowire features of Spring. @Primary By default, Spring will autowire by type. When you have more than one Spring Bean of a given type, you can […]Continue reading
I was recently asked on my Facebook page, “How do I become a Java Web Developer?” There is really no simple answer for this question. There are many facets to becoming a Java web developer. I’ve encountered Java developers who were good front end developers, or good backend developers. By ‘front end’, I mean more of […]Continue reading
Testing software has many meanings, which are often confused. In the last decade or so, we’ve seen agile development methodologies go mainstream in the modern enterprise. These methodologies are often misunderstood and misused. Some times they assume you have clean testable code. Often, when dealing with legacy applications, you simply don’t. I’ve encountered legacy Java […]Continue reading
