Bean 的配置方式：通过全类名（反射）、通过工厂方法（静态工厂方法 & 实例工厂方法）、FactoryBean

这里依据全类名配置bean

<bean id="helloWord" class="com.spring.HelloWord">

 <property name="userName" value="springsss"></property>

</bean>

依赖注入发方式：

属性注入：

applicationContext.xml配置文件为：

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"

   xmlns:p="http://www.springframework.org/schema/p"

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">

<!-- 配置bean -->

<bean id="helloWord" class="com.spring.HelloWord">

 <property name="userName" value="springsss"></property>

</bean>

</beans>

package com.spring;

public class HelloWord {

private String userName;

public void setUserName(String userName) {

this.userName = userName;

}

public void hello() {

System.out.println("hello:" + userName);

}

public HelloWord(){

System.out.println("construct!!!!!!!!!!");

}

}

package com.spring;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Test {

public static void main(String[] args) {

/**

* 创建对象及为对象赋值交给spring完毕

*/

// HelloWord helloWord = new HelloWord();

// helloWord.setUserName("hello");

// helloWord.hello();

//1.创建spring IOC容器

ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");

//2从容器中获得Bean

HelloWord helloWord = (HelloWord) ctx.getBean("helloWord");

//3.调用方法

helloWord.hello();

}

}

输出结果为：

construct!!!!!!!!!!

hello:springsss

构造器注入：

applicationContext.xml文件为

<?xml version="1.0" encoding="UTF-8"?

>

<beans xmlns="http://www.springframework.org/schema/beans"

   xmlns:p="http://www.springframework.org/schema/p"

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">

<!-- 配置bean -->

<bean id="car" class="com.spring.Car">

<constructor-arg value="green"></constructor-arg>

<constructor-arg value="22"></constructor-arg>

</bean>

</beans>

public class Car {

 private String name;

 private String color;

 private int num;

public Car(String color, int num) {

super();

this.color = color;

this.num = num;

}

@Override

public String toString() {

return "Car [name=" + name + ", color=" + color + ", num=" + num + "]";

}

}

package com.spring;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Test {

public static void main(String[] args) {

//1.创建spring IOC容器

ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");

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

System.out.println(car.toString());

}

}

输出结果为：

Car [name=null, color=green, num=22]