4-4 object lifecycle

explain ： In this section ioc Which stage of the container bean What did you do

 

  Illustrate with a case

  Create order attributes

 

  go back to xml To configure

  Do you want to calculate the price manually ？ Where are we going to let the program calculate ？

  It's right to do so, but every call requires an operation

increase init Method

 

  Take advantage of init-method It is the feature of executing after setting properties total Calculation of properties

In order to make the program run more clearly , We print some text at every step of object creation and property setting

 

 

 

 

function  

  Release resources when destroying , How do you do that ？

  Added for destruction ioc Container method , This method does not exist in applicationContext This interface is defined in... Instead classPathXmlapplicationContext In this concrete implementation class , Therefore, when calling a method, it is determined by idea Automatically convert back to the specific implementation class for us

The process of destroying the container will automatically call us in bean Set in the

Method  

  What does resource mean ？ In fact, during the process of program operation, these resources , It can be a file , It can also be a network connection , It can even be called by other systems , These are called resources , And in the destory We will release these resources ,

Run it