java：Inverse Of Control （IOC，控制反转）

 

Inverse Of Control  （IOC，控制反转）

 

 

 

 

一、Inverse Of Control（IOC）的本质

 

　　1、IOC（控制反转）：程序把创建对象的任务，委托第三方（spring框架）完成。

 

 

 

 

二、IOC详解

 

　　

[root@rockylinux tmp]# java -version
java version "17.0.1" 2021-10-19 LTS
Java(TM) SE Runtime Environment (build 17.0.1+12-LTS-39)
Java HotSpot(TM) 64-Bit Server VM (build 17.0.1+12-LTS-39, mixed mode, sharing)
[root@rockylinux tmp]# cat test.java 
// test.java




class book{
        public book(){}
        public book(String ...parameters){}
        public book(book obj){}
        public void msg(){ System.out.println("book.msg():  hello, world!"); }
}




// core class
class spring_usr
{
        public spring_usr(){}

        public book create_obj( String ...para)
        {
                book tmp = new book(para);
                return tmp;
        }
}




// test functoins
public class test
{
        public static void main(String[] args)
        {

                System.out.println("hello, java17!");


                // create object normally
                book b1 = new book();


                // Inverse of Control (IOC), create object by SPRING frame

                spring_usr sp = new spring_usr();
                book b2 = sp.create_obj("hello", "hi");
                b2.msg();

        }
}

[root@rockylinux tmp]# javac test.java 
[root@rockylinux tmp]# java test 
hello, java17!
book.msg():  hello, world!
[root@rockylinux tmp]# 
[root@rockylinux tmp]# 
[root@rockylinux tmp]# 
[root@rockylinux tmp]#