Spring Dependency Injection ● A kind of Inversion of Control (IoC) ● “Hollywood Principle”          – Don’t call me, I’ll call you ● “Container” resolves (injects) dependencies of components by setting implementation object (push) ● As opposed to component instantiating or Service Locator pattern where component locates implementation (pull) ● Martin Fowler calls it Dependency Injection. Benefits of… Read More Spring Dependency Injection Basics

What is Spring Framework? ● Light-weight yet comprehensive framework for building Java SE and Java EE applications. Key Features – DI ● JavaBeans-based configuration management, applying Inversion-of-Control principles, specifically using the Dependency Injection (DI) technique          – This aims to eliminate manual wiring of components ● A core bean factory, which is usable… Read More Spring Basics

BEA WebLogic On WebLogic 8.1 or above, you will generally prefer to use the WebLogicJtaTransactionManager instead of the stock JtaTransactionManager class. This special WebLogic-specific subclass of the normal JtaTransactionManager supports the full power of Spring’s transaction definitions in a WebLogic-managed transaction environment, beyond standard JTA semantics: Features include transaction names, per-transaction isolation levels, and proper… Read More Transaction management

Controlling database connections DataSource Spring obtains a connection to the database through a DataSource. A DataSource is part of the JDBC specification and is a generalized connection factory. It allows a container or a framework to hide connection pooling and transaction management issues from the application code. When using Spring’s JDBC layer, you obtain a… Read More Data access with JDBC

ApplicationContext is an extension of BeanFactory: it provides all the same functionality, but it reduces the amount of code you need to interact with it and adds new features into the pot for good measure. When using an ApplicationContext, you can control bean instantiation declaratively on a bean-by-bean basis, and any BeanPostProcessors and BeanFactoryPostProcessors registered in the ApplicationContext are… Read More The Spring ApplicationContext

The BeanPostProcessor Sometimes, youmay find yourself in a position where you need to performsome additional processing immediately before and after Spring instantiates the bean. The processing can be as simple as modifying the bean or as complex as returning a completely different object! The BeanPostProcessor interface has two methods: postProcessBeforeInitialization, which is called before Spring calls any bean initialization… Read More The BeanPostProcessor

JavaBeans PropertyEditor The PropertyEditor class converts a property’s value to and from its native type representation into a String. Originally, this was conceived as a way to allow property values to be entered, as String values, into an editor and transform them into the correct types. However, because PropertyEditors are inherently lightweight classes, they have… Read More JavaBeans PropertyEditor

The BeanFactoryPostProcessor The concept of the BeanFactoryPostProcessor is similar to the BeanPostProcessor: the BeanFactoryPostProcessor executes after Spring has finished constructing the BeanFactory but before the BeanFactory constructs the beans.Using the BeanFactoryPostProcessor, we can adapt the beans’ values according to the BeanFactory’s environment BeanFactory Post-Processors in Spring AspectJWeavingEnabler  – This post-processor registers AspectJ’s ClassPreProcessorAgentAdapter to be… Read More The BeanFactoryPostProcessor

Using FactoryBean Spring provides the FactoryBean interface that acts as an adaptor for objects that cannot be created and managed using the standard Spring semantics. Typically, you use a FactoryBean to create beans you cannot use the new operator to create, such as those you access through static factory methods, although this is not always the… Read More Using FactoryBean

Making Your Beans Spring Aware Using the BeanNameAware Interface The BeanNameAware interface, which can be implemented by a bean that wants to obtain its own name, has a single method: setBeanName(String). Spring calls the setBeanName() method after it has finished configuring your bean but before any life cycle callbacks (to initialize or destroy) are called.… Read More Making Your Beans Spring Aware