代码改变世界

Bean的生命周期和创建方式

2018-09-13 20:37  kill-9  阅读(403)  评论(0)  编辑  收藏  举报 
 1 package spring;
 2 
 3 
 4 import org.springframework.context.support.ClassPathXmlApplicationContext;
 5 
 6 import java.util.Calendar;
 7 
 8 public class Circle {
 9 
10     private double radius;
11     private double peri;
12     private double area;
13 
14     public double getRadius() {
15         return radius;
16     }
17 
18     public void setRadius(double radius) {
19         this.radius = radius;
20     }
21 
22     public double getPeri() {
23         return peri;
24     }
25 
26     public void setPeri(double peri) {
27         this.peri = peri;
28     }
29 
30     public double getArea() {
31 
32         Calendar calendar = Calendar.getInstance();
33         return area;
34     }
35 
36     public void setArea(double area) {
37         this.area = area;
38         System.out.println("执行Circle的setArea方法...");
39     }
40 
41 
42 
43     public Circle(double radius) {
44         this.radius = radius;
45         System.out.println("执行Circle构造方法...");
46     }
47 
48     @Override
49     public String toString() {
50         return "Circle{" +
51                 "radius=" + radius +
52                 ", peri=" + peri +
53                 ", area=" + area +
54                 '}';
55     }
56 
57 
58     public void init(){
59         System.out.println("执行Circle对象初始化...");
60     }
61 
62 
63     public void destroy(){
64         System.out.println("执行Circle对象销毁...");
65     }
66 
67 
68     public static void main(String[] args){
69         ClassPathXmlApplicationContext cc = new ClassPathXmlApplicationContext("classpath:spel.xml");
70         Circle life = cc.getBean("life",Circle.class);
71         System.out.println(life);
72         cc.close();
73     }
74 
75 
76 }
 1 package spring.annotation;
 2 
 3 import org.springframework.stereotype.Component;
 4 
 5 @Component
 6 public class AutoBean {
 7 
 8     private String info = "AutoBean";
 9 
10     public String getInfo() {
11         return info;
12     }
13 
14     public void setInfo(String info) {
15         this.info = info;
16     }
17 
18     @Override
19     public String toString() {
20         return "AutoBean{" +
21                 "info='" + info + '\'' +
22                 '}';
23     }
24 }
 1 package spring.annotation;
 2 
 3 import org.springframework.stereotype.Component;
 4 
 5 
 6 @Component(value = "component")
 7 public class DemoComponent {
 8 
 9     public void print(){
10         System.out.println(this.getClass().getName());
11     }
12 
13 
14 }
 1 package spring.annotation;
 2 
 3 import org.springframework.beans.factory.annotation.Autowired;
 4 import org.springframework.stereotype.Controller;
 5 
 6 @Controller(value = "controller")
 7 public class DemoController {
 8 
 9 
10     @Autowired
11     private AutoBean bean;
12 
13     public void print(){
14         System.out.println(this.getClass().getName());
15         System.out.println(bean);
16     }
17 
18 
19 }
 1 package spring.annotation;
 2 
 3 import org.springframework.stereotype.Controller;
 4 import org.springframework.stereotype.Repository;
 5 
 6 @Repository(value = "repository")
 7 public class DemoRepository{
 8 
 9     public void print(){
10         System.out.println(this.getClass().getName());
11     }
12 
13 
14 }
 1 package spring.annotation;
 2 
 3 import org.springframework.stereotype.Controller;
 4 import org.springframework.stereotype.Service;
 5 
 6 @Service(value = "service")
 7 public class DemoService {
 8 
 9     public void print(){
10         System.out.println(this.getClass().getName());
11     }
12 
13 
14 }

spring配置文件

<?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"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">

    <!--
        bean的生命周期[Spring IOC容器管理]
            - 通过构造器或者工厂方法创建Bean的实例
            - 为Bean的属性设置值或者引用其他的Bean
            - 调用Bean的初始化方法
            - 使用Bean
            - 容器关闭时，调用Bean的销毁方法

     -->
    <!--定义Bean的初始化和销毁方法-->
    <!--构造方法创建Bean-->
    <!--<bean id="life" class="spring.Circle" init-method="init" destroy-method="destroy">-->
        <!--<constructor-arg name="radius" value="40"/>-->
        <!--<property name="area" value="#{T(java.lang.Math).PI * circle.radius^2}"/>-->
    <!--</bean>-->


    <!--静态方法创建Bean-->
    <bean id="calendar" class="java.util.Calendar" factory-method="getInstance"/>
    <!--通过工厂bean的普通方法创建Bean-->
    <bean id="time" factory-bean="calendar" factory-method="getTime"/>

    <!--
        通过FactoryBean配置Bean的实例
        class指向FactoryBean的全类名
        property配置FactoryBean的属性
        实际返回的是FactoryBean的getObject()方法返回的实例
    -->

    <bean id="factoryBean" class="spring.DemoFactoryBean">
        <property name="mod" value="#{T(java.lang.Math).ceil(T(java.lang.Math).random()*101)}"/>
    </bean>


    <!--通过注解扫描创建Bean-->
    <!--resource-pattern 只扫描特定的文件或者包-->
    <!--<context:component-scan base-package="spring" resource-pattern="annotation/DemoService.class" />-->

    <context:component-scan base-package="spring.annotation" use-default-filters="true">
        <!--<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Component"/>-->
        <!--<context:include-filter type="annotation" expression="org.springframework.stereotype.Component"/>-->

        <!--从扫描包中排除指定的类或者接口-->
        <context:exclude-filter type="assignable" expression="spring.annotation.DemoComponent"/>
        <!--<context:include-filter  type="assignable" expression="spring.annotation.DemoComponent"/>-->

    </context:component-scan>

</beans>