这篇文章给大家介绍spring与bean的关系是什么，内容非常详细，感兴趣的小伙伴们可以参考借鉴，希望对大家能有所帮助。
一、继承关系
Address.java
计算
安全
数据库
网络和加速
企业服务
package com.gong.spring.beans.autowire;
public class Address {
private String city;
private String street;
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
public String getStreet() {
return street;
}
public void setStreet(String street) {
this.street = street;
}
@Override
public String toString() {
return "Address [city=" + city + ", street=" + street + "]";
}
}beans-relation.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"
xmlns:p="http://www.springframework.org/schema/p"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
<bean id="address" class="com.gong.spring.beans.autowire.Address"
p:city="武汉" p:street="络南街道"></bean>
<!-- 使用parent指定指定哪个bean的配置，子bean可以覆盖父bean的配置 -->
<bean id="address2" class="com.gong.spring.beans.autowire.Address" parent="address"
p:street="珞狮街道"></bean>
</beans>Main.java
package com.gong.spring.beans.autowire;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Main {
public static void main(String[] args) {
//1.创建spring的IOC容器对象
ApplicationContext ctx = new ClassPathXmlApplicationContext("beans-relation.xml");
//2.从容器中获取Bean实例
Address address = (Address) ctx.getBean("address");
System.out.println(address.toString());
Address address2 = (Address) ctx.getBean("address2");
System.out.println(address2.toString());
}
}输出：
address2继承了address的city配置，因此city=武汉。
当然，我们也可以使用abstract来表明一个Bean是一个抽象bean。抽象bean可以作为一个模板，且不能被实例化。同时，如果一个bean没有声明class，那么该bean也是一个抽象bean，且必须指定abstract="true"。
<bean id="address" class="com.gong.spring.beans.autowire.Address" abstract="true"
p:city="武汉" p:street="络南街道"></bean>此时，在进行实例化就会报错
Address address = (Address) ctx.getBean("address");
将抽象bean作为父bean，可以实例化它的子bean：
Address address2 = (Address) ctx.getBean("address2");
System.out.println(address2.toString());
二、依赖关系
Car.java
package com.gong.spring.beans.autowire;
public class Car {
public Car() {
}
public Car(String name) {
this.name = name;
}
private String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@Override
public String toString() {
return "Car [name=" + name + "]";
}
}Student.java
package com.gong.spring.beans.autowire;
import java.util.List;
import java.util.Map;
public class Student {
private String name;
private int age;
private double score;
private Car car;
private Address address;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public double getScore() {
return score;
}
public void setScore(double score) {
this.score = score;
}
public Car getCar() {
return car;
}
public void setCar(Car car) {
this.car = car;
}
public Address getAddress() {
return address;
}
public void setAddress(Address address) {
this.address = address;
}
@Override
public String toString() {
return "Student [name=" + name + ", age=" + age + ", score=" + score + ", car=" + car + ", address=" + address
+ "]";
}
}beans-relation.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"
xmlns:p="http://www.springframework.org/schema/p"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
<bean id="car" class="com.gong.spring.beans.autowire.Car" p:name="baoma"></bean>
<bean id="address" class="com.gong.spring.beans.autowire.Address"
p:city="武汉" p:street="络南街道"></bean>
<!-- 要求配置Student时，要依赖于Car-->
<bean id="student" class="com.gong.spring.beans.autowire.Student" p:name="tom"
p:age="12" p:score="99.00" autowire="byName" depends-on="car"></bean>
</beans>spring允许用户通过depends-on属性设定bean前置依赖bean，前置依赖bean会在本Bean实例化之前就创建好。如果前置依赖于多个Bean，则可以通过逗号，空格的方式来配置bean的名称。
Main.java
package com.gong.spring.beans.autowire;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Main {
public static void main(String[] args) {
//1.创建spring的IOC容器对象
ApplicationContext ctx = new ClassPathXmlApplicationContext("beans-relation.xml");
//2.从容器中获取Bean实例
Student student = (Student) ctx.getBean("student");
System.out.println(student.toString());
}
}输出：
关于spring与bean的关系是什么就分享到这里了，希望以上内容可以对大家有一定的帮助，可以学到更多知识。如果觉得文章不错，可以把它分享出去让更多的人看到。
亿速云「云服务器」，即开即用、新一代英特尔至强铂金CPU、三副本存储NVMe SSD云盘，价格低至29元/月。点击查看>>
免责声明：本站发布的内容（图片、视频和文字）以原创、转载和分享为主，文章观点不代表本网站立场，如果涉及侵权请联系站长邮箱：is@yisu.com进行举报，并提供相关证据，一经查实，将立刻删除涉嫌侵权内容。
