In this Spring Data JPA One To Many article, we will learn how to achieve One To Many Mapping using Spring Data JPA. In this approach, we will re-use the same two tables which we used in our previous Spring Data JPA One To One Example. [Read more…]
In this Spring CRUD Example, we will build a Simple Spring Application and perform CRUD operations using Spring JdbcTemplate. We will create a simple Employee management application which has abilities to create a new employee, update the existing employee, get a particular employee/ all employee and finally delete the existing employee. [Read more…]
Spring framework provides excellent support to JDBC, it provides a super powerful utility class called “JdbcTemplate” which helps us avoid boiler-plate code from our database operations such as Creating Connection, Statement, Closing the Resultset and Connection, Exception handling, Transaction management etc. In this Spring JdbcTemplate Example, let’s understand how JdbcTemplate eases the development effort. [Read more…]
It’s never a good practice to hard code and combine any environment related details such a username, password or file path etc. along with spring bean configuration. Usually in Java we will be having those details written in a separate property file and it will be read during the execution, the same can be followed in the spring as well using PropertyPlaceholderConfigurer.
Spring comes with a bean factory post processor called PropertyPlaceholderConfigurer which allows you to externalize those details into a properties file. In this Spring PropertyPlaceholderConfigurer Example we will learn how to use the PropertyPlaceholderConfigurer. [Read more…]
In Spring we can create bean using Spring FactoryBean, FactoryBean is an interface and we need to give implementations for the methods in it. If you don’t want to go by that methodology but still want Java Factory Pattern to be implemented then we can go for Static Factory Method and Instance Factory Method.
The client who requests for an object can simply make a call to the factory method which we have defined without knowing about the creation detail. We will be using factory-method and factory-bean attribute in our configuration for the Injection of Bean, through the below spring factory pattern example lets learn more about it. [Read more…]
Spring IoC container is also responsible for managing the Spring Bean Life Cycle, the life cycle of beans consist of call back methods such as Post initialization call back method and Pre destruction call back method. Below steps are followed by Spring IoC Container to manage bean life cycle.
Spring Bean Life Cycle
- Creation of bean instance by a factory method.
- Set the values and bean references to the bean properties.
- Call the initialization call back method.
- Bean is ready for use.
- Call the destruction call back method.
Spring Autowiring by using the “autowire” attribute in the bean configuration file we can wire all the properties of the bean class. Using Spring Autowiring through XML you cannot wire a particular property. In those cases we can use the Spring @Autowired annotation which allows auto-wiring of setter method, a constructor, a field, or even an arbitrary method.
For a large-scale application, there can be hundreds of bean declared in the Spring IoC container and managing dependency between them will be already complicated. Especially through Setter Injection, we cannot make sure that values for all the properties has been injected. Spring dependency checking feature will come into rescue in this situation which helps us to check if all/ certain property is injected or not. Spring dependency check can be turned on just by adding “dependency-check” attribute of the <bean> tag. [Read more…]
In Spring you can also Create and Configure of Spring Bean using Spring’s FactoryBean . A factory bean in Spring serves as a factory for creating other beans within the Spring IoC container. In Java terms we can say that, a factory bean is very similar to a factory method (Java Factory Pattern), but here it is Spring specific bean which can be identified by the Spring IoC container during bean construction. [Read more…]
If you are using Setter Injection or Constructor Injection to inject a simple data type then we will be using the <value> tag in the bean configuration file to inject. Whereas when we want to refer another bean then we have to use <ref> tag. Lets see how we can refer other bean in this Spring bean reference example. [Read more…]