spring 4 -28

section 4 : 

package com.luv2code.springdemo;

public class BaseballCoach implements Coach {
    @Override
    public String getDailyWorkout() {
        return "spend 30 minutes on batting practice";
    }
} 



package com.luv2code.springdemo;

public class MyApp {
    public static void main(String[] args) {
        // create the object
        Coach theCoach = new TrackCoach();
        
        // use the object
        System.out.println(theCoach.getDailyWorkout);
    }
}


  

package com.luv2code.springdemo;

public class TrackCoach implements Coach {
    @Override
    public String getDailyWorkout() {
        return "run a hard 5k";
    }
} 


// spring container 
// primary functions: 
// create and manage objects (Inversion of control)
// inject object's dependencies(Dependency injection)



// configuring spring container 
// 1 . xml config file   2, java annotation   3. java source code 

// spring dev process 
// 1 . configure spring beans 
//2 . create a spring container 
// 3 retrieve bean from spring container 


// step 1 : configure spring beans 
// file : applicationContext.xml
<beans ..>

    <bean id = "myCoach"
        class = "com.luv2code.springdemo.BaseballCoach">
    </bean>

</beans>


// id is like an alias , class path : fully qualified class name of implementation class 


// step 2 : create a spring container 
// spring container is generally known as ApplicationContext
// Specialized implementations : 
// ClassPathXmlApplicationContext
// AnnotationConfigApplicationContext


ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");

// step 3: retrieve beans from container 

Coach theCoach = context.getBean("myCoach", Coach.class);
// Coach.class is the interface of BaseballCoach


// spring bean is like java objects  





package com.luv2code.springdemo;
public class HelloSpringApp {
    public static void main (String[] args) {
        //load the spring config file 
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
        
        // retrieve bean from spring container
        Coach theCoach = context.getBean("myCoach", Coach.class);
        
        // call methods on the bean
        System.out.println(theCoach.getDailyWorkout());
    
        // close the context
        context.close();
    }
}

标签：Coach,container,spring,28,public,context,class
来源： https://www.cnblogs.com/tobeabetterpig/p/11497847.html