Spring学习--引用其他Bean , 内部Bean

引用其他Bean

1. 组成应用程序的 Bean 经常需要相互协作以完成应用程序的功能 , 要使 Bean 能够相互访问, 就必须在 Bean 配置文件中指定对 Bean 的引用。
2. 在 Bean 的配置文件中 , 可以通过 <ref> 元素或 ref 属性为 Bean 的属性或者构造器参数指定对 Bean 的引用。
3. 也可以在属性或者构造器里包含 Bean 的声明 , 这样的 Bean 称为内部 Bean。

 <?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="person" class="com.itdjx.spring.dependency.injection.Person">
         <property name="name" value="张三"/>
         <property name="age" value="23"/>
         <property name="sex" value="男"/>
         <property name="car" ref="car3"/>
     </bean>

     <bean id="car3" class="com.itdjx.spring.dependency.injection.Car">
         <constructor-arg value="BaoMa" index="0"/>
         <constructor-arg value="HuaChen" index="1"/>
         <constructor-arg value="230000" index="2" type="double"/>
     </bean>

     <bean id="car4" class="com.itdjx.spring.dependency.injection.Car">
         <constructor-arg value="BaoMa" index="0"/>
         <constructor-arg value="HuaChen" index="1"/>
         <constructor-arg value="230" type="int"/>
     </bean>

 </beans>

 package com.itdjx.spring.dependency.injection;

 /**
  * 属性注入
  *
  * @author Wáng Chéng Dá
  * @create 2017-02-28 15:14
  */
 public class Person {

     private String name;

     private String sex;

     private int age;

     private Car car;

     public String getName() {
         return name;
     }

     public void setName(String name) {
         this.name = name;
     }

     public String getSex() {
         return sex;
     }

     public void setSex(String sex) {
         this.sex = sex;
     }

     public int getAge() {
         return age;
     }

     public void setAge(int age) {
         this.age = age;
     }

     public Car getCar() {
         return car;
     }

     public void setCar(Car car) {
         this.car = car;
     }

     @Override
     public String toString() {
         return "Person{" +
                 "name='" + name + '\'' +
                 ", sex='" + sex + '\'' +
                 ", age=" + age +
                 ", car=" + car +
                 '}';
     }
 }

 package com.itdjx.spring.dependency.injection;

 /**
  * 构造器注入
  *
  * @author Wáng Chéng Dá
  * @create 2017-02-28 15:32
  */
 public class Car {

     private String brand;

     private String address;

     private double price;

     private int maxSpeed;

     public Car(String brand, String address, double price) {
         this.brand = brand;
         this.address = address;
         this.price = price;
     }

     public Car(String brand, String address, int maxSpeed) {
         this.brand = brand;
         this.address = address;
         this.maxSpeed = maxSpeed;
     }

     public Car(String brand, double price, int maxSpeed) {
         this.brand = brand;
         this.price = price;
         this.maxSpeed = maxSpeed;
     }

     public Car() {
     }

     @Override
     public String toString() {
         return "Car{" +
                 "brand='" + brand + '\'' +
                 ", address='" + address + '\'' +
                 ", price=" + price +
                 ", maxSpeed=" + maxSpeed +
                 '}';
     }
 }

 package com.itdjx.spring.dependency.injection;

 import org.springframework.context.ApplicationContext;
 import org.springframework.context.support.ClassPathXmlApplicationContext;

 /**
  * 依赖注入main
  *
  * @author Wáng Chéng Dá
  * @create 2017-02-28 15:16
  */
 public class MainIOC {

     public static void main(String[] args) {
         ApplicationContext app = new ClassPathXmlApplicationContext("applicationConfig.xml");
         Person person = (Person) app.getBean("person");
         System.out.println(person);

     }
 }

控制台输出：

Person{name='张三', sex='男', age=23, car=Car{brand='BaoMa', address='HuaChen', price=230000.0, maxSpeed=0}}

内部Bean

 <?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="person2" class="com.itdjx.spring.dependency.injection.Person">
         <property name="name" value="李玉"/>
         <property name="age" value="23"/>
         <property name="sex" value="女"/>
         <property name="car" >
             <bean class="com.itdjx.spring.dependency.injection.Car">
                 <constructor-arg value="Ferrari" index="0"/>
                 <constructor-arg value="Italy" index="1"/>
                 <constructor-arg value="22500000" type="double"/>
             </bean>
         </property>
     </bean>

 </beans>

 package com.itdjx.spring.dependency.injection;

 import org.springframework.context.ApplicationContext;
 import org.springframework.context.support.ClassPathXmlApplicationContext;

 /**
  * 依赖注入main
  *
  * @author Wáng Chéng Dá
  * @create 2017-02-28 15:16
  */
 public class MainIOC {

     public static void main(String[] args) {
         ApplicationContext app = new ClassPathXmlApplicationContext("applicationConfig.xml");

         Person person = (Person) app.getBean("person2");
         System.out.println(person);

     }
 }

控制台输出：

Person{name='李玉', sex='女', age=23, car=Car{brand='Ferrari', address='Italy', price=2.25E7, maxSpeed=0}}