Meaning of Autowiring
Autowiring means initializing objects contained in a class automatically. Suppose you have a class which contains reference of another class as a member field. Now in order to initialize the member field you create an object of member field type and assign it manually (when not using Autowiring). (more…)
It is always advisable not to use configuration values inside your application code directly. Rather, supply them through configuration files which are external to the code. For Example, almost all applications involve database interaction wherein they connect to a database. Obviously there are database connection parameters such as database server url, database port etc. If they are hard-coded inside the code, then for every change in those parameters (suppose for a change in database server URL), the code will have to be touched. If they are supplied through an external properties file, then changing them would only require a restart of application or not even that in some cases. (more…)
Suppose we have a jsp page which has a form whose data should be sent to the server. The form has fields which are directly related to the fields of an entity on the server. An entity is a simple java class which has some fields and their getter and setter methods.
Let’s say the entity is a User (which means we have a User class on the server and each field of the jsp form is linked to a field of User class. When we say linked, it simply means that the name attribute of the form element is the same as the name of the corresponding entity field. (more…)
There are scenarios where we want to take some actions before a bean is fully constructed and put into service such as
- giving a specific name to the bean other than that given in the configuration,
- setting the application context into a bean property,
- making a log entry immediately after bean initialization etc.