spring ioc的xml形式实现

导入依赖(idea需要配置 JDK 17或者降低spring-context版本)

复制代码

<dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>6.0.6</version>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-api</artifactId>
            <version>5.3.1</version>
        </dependency>
    </dependencies>

一、无参构造方法实现ioc

待注入容器的bean定义

public class JavaBean implements JavaBeanInteface{
public void doWork(){
System.out.println("JavaBean.doWork");
}
}
实现的接口定义

public interface JavaBeanInteface {
}
.xml文件（放在resouces目录下）定义bean信息
<?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="javaBean" class="com.binbin.ioc.JavaBean"></bean>
</beans>
获取和使用bean

方式一：通过id获取bean

ApplicationContext applicationContext = new ClassPathXmlApplicationContext("spring-01.xml");
JavaBean javaBean = (JavaBean) applicationContext.getBean("javaBean"); // 1.通过id 获取bean对象
javaBean.doWork();
方式二：通过bean的类型获取bean

JavaBean javaBean1 = applicationContext.getBean(JavaBean.class);
方式三：通过bean的id和类型获取bean

JavaBean javaBean2 = applicationContext.getBean("javaBean",JavaBean.class);
方式四：通过bean实现的接口的类型获取bean(确保接口只有一个子类，否则容器不知道获取哪一个)

JavaBean javaBean3 = (JavaBean) applicationContext.getBean(JavaBeanInteface.class);

二、通过静态工厂实现ioc

待注入容器的bean定义

public class Car {
private String make;
private String model;

复制代码

 // 带参数的构造函数
 public Car(String make, String model) {
     this.make = make;
     this.model = model;
 }

 // getters and setters
 public String getMake() {
     return make;
 }

 public void setMake(String make) {
     this.make = make;
 }

 public String getModel() {
     return model;
 }

 public void setModel(String model) {
     this.model = model;
 }

}

静态工厂类定义

public class CarFactory {
// 静态工厂方法
public static Car createCar(String make, String model) {
return new Car(make, model);
}
}
.xml文件（放在resouces目录下）定义bean信息
<bean id="car" class="com.binbin.ioc.CarFactory" factory-method="createCar"> <constructor-arg name="make" value="奔驰"></constructor-arg> <constructor-arg name="model" value="模型"></constructor-arg> </bean>
获取bean和使用bean

通过id获取
通过bean类型获取

Car car = (Car) applicationContext.getBean("car");

Car car = applicationContext.getBean(Car.class)

注：静态工厂本身不会被实例化，不会存入ioc容器

三、通过实例工厂实现ioc

待注入容器的bean定义

public class Car {
private String make;
private String model;

复制代码

 // 带参数的构造函数
 public Car(String make, String model) {
     this.make = make;
     this.model = model;
 }

 // getters and setters
 public String getMake() {
     return make;
 }

 public void setMake(String make) {
     this.make = make;
 }

 public String getModel() {
     return model;
 }

 public void setModel(String model) {
     this.model = model;
 }

}

工厂类定义

public class CarFactory {
public Car createCarByInstantiation(String make, String model){
return new Car(make, model);
}
}
.xml文件（放在resouces目录下）定义bean信息

工厂本身也会被实例化注入容器
指定factory-bean和factory-method
构造函数有参数指定参数即可
<?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="carFactory1" class="com.binbin.ioc.CarFactory">
</bean>
<bean id="car1" factory-bean="carFactory1" factory-method="createCarByInstantiation">
<constructor-arg name="make" value="Toyota" />
<constructor-arg name="model" value="Camry" />
</bean>
</beans>

获取bean和使用bean

通过id获取bean

Car car1 = (Car) applicationContext.getBean("car1");
通过bean的类型获取bean

Car car1 = applicationContext.getBean(Car.class);
通过id和bean类型获取bean

Car car1 = (Car) applicationContext.getBean("car1",Car.class);

小结

总的来说，大概几个步骤，搭建maven工程、引入依赖、定义类、xml定义类信息、实例化容器ClassPathXmlApplicationContext、通过bean的id、类型获取到bean