The Spring core IOC

IOC is one of the two cores of spring: The core of the IOC is decoupling.

For example: There are 2 classes can be classes, the principal designated teachers to attend classes, the code is as follows

　　

 Package com.hongcong.test;  Public class Class1 {    publicvoid  teach () {        System.out.println ("one Class in Class");}    }

 Package com.hongcong.test;  Public class Class2  {    publicvoid  teach () {        System.out.println ("Class two is in class");}    }

Teacher

 Package com.hongcong.test;  Public class Teacher {        publicvoid  Doteach () {        new  Class1 ();        Class1.teach ();            }}

Principal

 package   Com.hongcong.service;  import   Com.hongcong.test.Class1;  import   Com.hongcong.test.Class2;  import   Com.hongcong.test.teacher;  public  class   Principal { public  static  void   main (string[] args) {T        Eacher teacher  = new   teacher ();            Teacher.doteach (); }}

At this time to run the headmaster, class began. But if the headmaster wants the teacher to go to class two, either revise the teacher's method, or add the teacher's method and revise the headmaster's method. As you can see, the code at this point is coupled together. This time you can use the IOC's ideas to redesign the program, the code is as follows:

Define a class interface, then class one and class two to implement this interface:

 Package com.hongcong.test;  Public Interface Teachinterface {    publicvoid  teach ();}

 package   com.hongcong.test;  public  class  Class1 implements   teachinterface{ public  void   teach (    {SYSTEM.OUT.PRINTLN ( class in class "

 package   com.hongcong.test;  public  class  Class2 implements   teachinterface{ public  void   teach (    {SYSTEM.OUT.PRINTLN ( class two in class "

 Package com.hongcong.test;  Public class Teacher {     private  teachinterface teachinterface;          Public void setteachinterface (Teachinterface teachinterface) {        this. Teachinterface=  teachinterface;    }       Public void Doteach () {                teachinterface.teach ();    }}

 PackageCom.hongcong.service;ImportCom.hongcong.test.Class1;ImportCom.hongcong.test.Class2;ImportCom.hongcong.test.teacher; Public classPrincipal { Public Static voidMain (string[] args) {Teacher Teacher=Newteacher (); Teacher.setteachinterface (NewClass2 ());    Teacher.doteach (); }}

At this time, if the headmaster wants to let the teacher go to class, only need to modify teacher.setteachinterface (new Class2 ()); The parameters in the method are available. The teacher has been and to which class class completely has no relationship, as long as the headmaster next instruction.

The Spring core IOC