《Spring视频教程》（p2）
p2 解耦合发展史、控制反转、依赖注入
IOC(控制反转）也可以称之为DI(依赖注入）：
控制反转：将创建对象、属性值的方式进行了反转，从new,setXxx()反转为了从springIOC容器getBean()
依赖注入：将属性值注入给了属性，将属性注入给了bean，将bean注入给了ioc容器
总结：ioc/di， 无论要什么对象，都可以直接去springioc容器中获取，而不需要自己操作
因此，之后的ioc分为2步：1.先给springioc中存放对象并赋值 2.拿
Test.java
package org.lanqiao.test;import org.lanqiao.entity.Student;
import org.lanqiao.factory.CourseFactory;
import org.lanqiao.newinstance.ICourse;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;public class Test {public static void learnCourseWithFactory() {Student student = new Student();student.learn("java");}public static void learnCourseWithIoC() {ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");//执行从springIOC容器中获取一个id为student的对象Student student = (Student)context.getBean("student");student.learn("htmlCourse");}public static void main(String [] args) {//传统的方式：
// Student student = new Student();
// student.setStuNo(1);
// student.setStuName("zs");
// student.setStuAge(23);
// System.out.println(student);// //新的方式
// //Spring上下文对象：context
// ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
// //执行从springIOC容器中获取一个id为student的对象
// Student student = (Student)context.getBean("student");
// System.out.println(student);learnCourseWithIoC();}
}
Stduent.java
package org.lanqiao.entity;import org.lanqiao.factory.CourseFactory;
import org.lanqiao.newinstance.HtmlCourse;
import org.lanqiao.newinstance.ICourse;
import org.lanqiao.newinstance.JavaCourse;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;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;}@Overridepublic String toString() {return "Student [stuNo=" + stuNo + ", stuName=" + stuName + ", stuAge=" + stuAge + "]";}public void learn(String name) {//1. 从自己编写的简单工厂中获取课程
// ICourse course = CourseFactory.getCourse(name);//course就是根据name拿到的相应的课程//直接从ioc容器中获取//2. 从SpringIOC提供的超级工厂中获取课程ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");ICourse course = (ICourse)context.getBean(name);course.learn();}//学习java课程public void learnJava() {ICourse course = new JavaCourse();course.learn();}//学习html课程public void learnHtml() {ICourse course = new HtmlCourse();course.learn();} }
applicationContext.xml
<?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"><!-- 该文件中产生的所有对象，被spring放入了一个称之为spring ioc容器的地方 --><!-- id:唯一标识符 class：指定类型 --><bean id="student" class="org.lanqiao.entity.Student"><!-- property: 该class所代表的类的属性name: 属性名value: 属性值--><property name="stuNo" value="2"></property><property name="stuName" value="ls"></property><property name="stuAge" value="24"></property></bean><bean id="javaCourse" class="org.lanqiao.newinstance.JavaCourse"></bean><bean id="htmlCourse" class="org.lanqiao.newinstance.HtmlCourse"></bean></beans>