Spring之控制反转、依赖注入

一、控制反转：将创建对象、属性值的方式进行了反转，从new、setxxx()变为从SpringIOC中getbean()；

二、依赖注入：将属性值注入给属性，将属性注入给bean，将bean注入给了SpringIOC;

创建接口类,ICourse.java:

package org.ruangong.newinstance;

public interface ICourse {
	void learn();//学习
}

　　创建实现类，HtmlCourse:

package org.ruangong.newinstance;

public class HtmlCourse implements ICourse{
	
	@Override
	public void learn() {
		// TODO Auto-generated method stub
		System.out.println("学习html中......");
	}
}

　　创建实现类，JavaCourse:

package org.ruangong.newinstance;

public class JavaCourse implements ICourse{
	
	@Override
	public void learn() {
		// TODO Auto-generated method stub
		System.out.println("学习JAVA......");
	}
}

　　实体类：

package org.ruangong.entity;

import org.ruangong.factory.CourseFactory;
import org.ruangong.newinstance.HtmlCourse;
import org.ruangong.newinstance.ICourse;
import org.ruangong.newinstance.JavaCourse;

public class Student {
	private int stuNo;
	private String stuName;
	private int stuAge;
	public int getStuNo() {
		return stuNo;
	}
	public void setStuNo(int stuNo) {
		this.stuNo = stuNo;
	}
	public String getStuName() {
		return stuName;
	}
	public void setStuName(String stuName) {
		this.stuName = stuName;
	}
	public int getStuAge() {
		return stuAge;
	}
	public void setStuAge(int stuAge) {
		this.stuAge = stuAge;
	}
	@Override
	public String toString() {
		return "Student [stuNo=" + stuNo + ", stuName=" + stuName + ", stuAge=" + stuAge + "]";
	}
	
	
	
	public void learnJavaWithIoc(){
		ICourse course = new JavaCourse();
		course.learn();
	}
	
	public void learnHtmlWithIoc(){
		ICourse course = new HtmlCourse();
		course.learn();
	}
	
	public void learnAnyone(String name){
		ICourse course = CourseFactory.getCourse(name);
		course.learn();
	}
}

　　工厂类：

package org.ruangong.factory;

import org.ruangong.newinstance.HtmlCourse;
import org.ruangong.newinstance.ICourse;
import org.ruangong.newinstance.JavaCourse;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class CourseFactory {
	
	public static ICourse getCourse(String name){
		ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
		if(name.equals("java")){
			return (ICourse) context.getBean("JavaCourse");
		}else{
			return (ICourse) context.getBean("HtmlCourse");
		}
	}
}

　　测试类：

public static void learnCourseWithFactory(){
Student student = new Student();
student.learnAnyone("java");
}

ApplicationContext.xml文件;

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
	
	<bean id="student" class="org.ruangong.entity.Student">
		<property name="stuNo" value="20173681"></property>
		<property name="stuName" value="靳晨晨"></property>
		<property name="stuAge" value="21"></property>
	</bean>

	<bean id="JavaCourse" class="org.ruangong.newinstance.JavaCourse"></bean>
	<bean id="HtmlCourse" class="org.ruangong.newinstance.HtmlCourse"></bean>
	
</beans>