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1437 lines
38 KiB
Markdown
1437 lines
38 KiB
Markdown
---
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title: Spring常用注解
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tags:
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- Spring
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- 注解
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categories:
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- Spring
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- 用法
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keywords: Spriong，框架
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description: 一些常用的注解
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cover: 'https://cdn.jsdelivr.net/gh/youthlql/youthlql/img/spring.png'
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abbrlink: 1a003b7b
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date: 2021-10-06 00:21:58
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---
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> 参考了尚硅谷注解版，注解版后面的源码没看，雷神讲的太散了
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## Spring注解
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### AnnotationConfigApplicationContext
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### 组件添加
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#### @Configuration+@Bean
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##### XML文件方式
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###### Person
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```java
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public class Person {
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private String name;
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private Integer age;
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private String nickName;
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public String getNickName() {
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return nickName;
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}
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public void setNickName(String nickName) {
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this.nickName = nickName;
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}
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public String getName() {
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return name;
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}
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public void setName(String name) {
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this.name = name;
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}
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public Integer getAge() {
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return age;
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}
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public void setAge(Integer age) {
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this.age = age;
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}
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public Person(String name, Integer age) {
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super();
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this.name = name;
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this.age = age;
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}
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public Person() {
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super();
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// TODO Auto-generated constructor stub
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}
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@Override
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public String toString() {
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return "Person [name=" + name + ", age=" + age + ", nickName=" + nickName + "]";
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}
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}
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```
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###### beans.xml-配置文件
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```xml
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<?xml version="1.0" encoding="UTF-8"?>
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<beans xmlns="http://www.springframework.org/schema/beans"
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xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
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xmlns:context="http://www.springframework.org/schema/context"
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xmlns:aop="http://www.springframework.org/schema/aop"
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xmlns:tx="http://www.springframework.org/schema/tx"
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xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
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http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd
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http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsd
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http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.3.xsd">
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<context:component-scan base-package="com.atguigu" use-default-filters="false"></context:component-scan>
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<bean id="person" class="com.atguigu.bean.Person">
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<property name="age" value="18"></property>
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<property name="name" value="zhangsan"></property>
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</bean>
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</beans>
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```
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###### MainTest
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```java
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public class MainTest {
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@SuppressWarnings("resource")
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public static void main(String[] args) {
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ApplicationContext applicationContext = new ClassPathXmlApplicationContext("beans.xml");
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Person bean = (Person) applicationContext.getBean("person");
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System.out.println(bean);
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}
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}
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```
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输出
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```
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Person [name=zhangsan, age=18, nickName=null]
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```
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##### 注解方式
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```java
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//配置类==配置文件
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@Configuration //告诉Spring这是一个配置类
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public class MainConfig {
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//给容器中注册一个Bean;类型为返回值的类型，id默认是用方法名作为id(就是bean的名字)，在这里就是person01
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@Bean
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public Person person01(){
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return new Person("lisi", 20);
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}
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}
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```
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或者以下面的这种方式
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```java
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//配置类==配置文件
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@Configuration //告诉Spring这是一个配置类
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public class MainConfig {
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//这里bean的name就是person
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@Bean("person")
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public Person person01(){
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return new Person("lisi", 20);
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}
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}
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```
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#### @ComponentScans
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```java
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//配置类==配置文件
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@Configuration //告诉Spring这是一个配置类
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@ComponentScans(
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value = {
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@ComponentScan(value="com.atguigu",includeFilters = {
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/* @Filter(type=FilterType.ANNOTATION,classes={Controller.class}),
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@Filter(type=FilterType.ASSIGNABLE_TYPE,classes={BookService.class}),*/
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@Filter(type=FilterType.CUSTOM,classes={MyTypeFilter.class})
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},useDefaultFilters = false)
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}
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)
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//@ComponentScan value:指定要扫描的包
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//excludeFilters = Filter[] ：指定扫描的时候按照什么规则排除那些组件
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//includeFilters = Filter[] ：指定扫描的时候只需要包含哪些组件
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//FilterType.ANNOTATION：按照注解
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//FilterType.ASSIGNABLE_TYPE：按照给定的类型；
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//FilterType.ASPECTJ：使用ASPECTJ表达式
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//FilterType.REGEX：使用正则指定
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//FilterType.CUSTOM：使用自定义规则
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public class MainConfig {
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//给容器中注册一个Bean;类型为返回值的类型，id默认是用方法名作为id
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@Bean("person")
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public Person person01(){
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return new Person("lisi", 20);
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}
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}
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```
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##### 自定义TypeFilter指定包扫描规则
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```java
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public class MyTypeFilter implements TypeFilter {
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/**
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* metadataReader：读取到的当前正在扫描的类的信息
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* metadataReaderFactory:可以获取到其他任何类信息的
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*/
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@Override
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public boolean match(MetadataReader metadataReader, MetadataReaderFactory metadataReaderFactory)
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throws IOException {
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// TODO Auto-generated method stub
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//获取当前类注解的信息
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AnnotationMetadata annotationMetadata = metadataReader.getAnnotationMetadata();
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//获取当前正在扫描的类的类信息
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ClassMetadata classMetadata = metadataReader.getClassMetadata();
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//获取当前类资源（类的路径）
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Resource resource = metadataReader.getResource();
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String className = classMetadata.getClassName();
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System.out.println("--->"+className);
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if(className.contains("er")){
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return true;
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}
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return false;
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}
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}
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```
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#### @Scope
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```java
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@Configuration
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public class MainConfig2 {
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/**
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* @see ConfigurableBeanFactory#SCOPE_PROTOTYPE 任何环境都可以使用
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* @see ConfigurableBeanFactory#SCOPE_SINGLETON 任何环境都可以使用
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* @see org.springframework.web.context.WebApplicationContext#SCOPE_REQUEST request 只能在web容器里用
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* @see org.springframework.web.context.WebApplicationContext#SCOPE_SESSION sesssion 只能在web容器里用
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*
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* @Scope:调整作用域
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* prototype：多实例的：ioc容器启动并不会去调用方法创建对象放在容器中。
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* 每次获取的时候才会调用方法创建对象；
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* singleton：单实例的（默认值）：ioc容器启动会调用方法创建对象放到ioc容器中。
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* 以后每次获取就是直接从容器（map.get()）中拿，
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* request：同一次请求创建一个实例
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* session：同一个session创建一个实例
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*
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* 默认是单实例的
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*
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*/
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@Scope("prototype")
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@Lazy
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@Bean("person")
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public Person person(){
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System.out.println("给容器中添加Person....");
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return new Person("张三", 25);
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}
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}
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```
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#### @Lazy
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```java
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@Configuration
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public class MainConfig2 {
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/**
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*
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* 懒加载：
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* 单实例bean：默认在容器启动的时候创建对象；
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* 懒加载：容器启动不创建对象。第一次使用(获取)Bean创建对象，并初始化；
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*
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*/
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@Lazy
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@Bean("person")
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public Person person(){
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System.out.println("给容器中添加Person....");
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return new Person("张三", 25);
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}
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```
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#### @Conditional
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##### MainConfig2
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```java
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//类中组件统一设置。满足当前条件，这个类中配置的所有bean注册才能生效；
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@Conditional({WindowsCondition.class})
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@Configuration
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public class MainConfig2 {
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/**
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* @Conditional({Condition}) ： 按照一定的条件进行判断，满足条件给容器中注册bean
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*
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* 如果系统是windows，给容器中注册("bill")
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* 如果是linux系统，给容器中注册("linus")
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*/
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@Bean("bill")
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public Person person01(){
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return new Person("Bill Gates",62);
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}
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@Conditional(LinuxCondition.class)
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@Bean("linus")
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public Person person02(){
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return new Person("linus", 48);
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}
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}
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```
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##### LinuxCondition
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```java
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//判断是否linux系统
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public class LinuxCondition implements Condition {
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/**
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* ConditionContext：判断条件能使用的上下文（环境）
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* AnnotatedTypeMetadata：注释信息
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*/
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@Override
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public boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {
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// TODO是否linux系统
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//1、能获取到ioc使用的beanfactory
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ConfigurableListableBeanFactory beanFactory = context.getBeanFactory();
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//2、获取类加载器
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ClassLoader classLoader = context.getClassLoader();
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//3、获取当前环境信息
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Environment environment = context.getEnvironment();
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//4、获取到bean定义的注册类
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BeanDefinitionRegistry registry = context.getRegistry();
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String property = environment.getProperty("os.name");
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//可以判断容器中的bean注册情况，也可以给容器中注册bean
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boolean definition = registry.containsBeanDefinition("person");
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if(property.contains("linux")){
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return true;
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}
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return false;
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}
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```
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##### WindowsCondition
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```java
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//判断是否windows系统
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public class WindowsCondition implements Condition {
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@Override
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public boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {
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Environment environment = context.getEnvironment();
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String property = environment.getProperty("os.name");
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if(property.contains("Windows")){
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return true;
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}
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return false;
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}
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}
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```
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#### @Import
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##### MainConfig2
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```java
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@Configuration
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@Import({Color.class,Red.class,MyImportSelector.class,MyImportBeanDefinitionRegistrar.class})
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//@Import导入组件，id默认是组件的全类名
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public class MainConfig2 {
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/**
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* 给容器中注册组件；
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* 1）、包扫描+组件标注注解（@Controller/@Service/@Repository/@Component）[只能注册自己写的类]
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* 2）、@Bean[导入的第三方包里面的组件]
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* 3）、@Import[快速给容器中导入一个组件]
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* 1）、@Import(要导入到容器中的组件)；容器中就会自动注册这个组件，id默认是全类名
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* 2）、ImportSelector:返回需要导入的组件的全类名数组；
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* 3）、ImportBeanDefinitionRegistrar:手动注册bean到容器中
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*/
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@Bean
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public ColorFactoryBean colorFactoryBean(){
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return new ColorFactoryBean();
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}
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}
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```
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##### MyImportSelector
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```java
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//自定义逻辑返回需要导入的组件
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public class MyImportSelector implements ImportSelector {
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//返回值，就是到导入到容器中的组件全类名
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//AnnotationMetadata:@Import引入MyImportSelector的类的所有注解信息
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@Override
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public String[] selectImports(AnnotationMetadata importingClassMetadata) {
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//importingClassMetadata.get
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//方法不要返回null值，不然会报错
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return new String[]{"com.atguigu.bean.Blue","com.atguigu.bean.Yellow"};
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}
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}
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```
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##### MyImportBeanDefinitionRegistrar
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```java
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public class MyImportBeanDefinitionRegistrar implements ImportBeanDefinitionRegistrar {
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/**
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* AnnotationMetadata：当前类的注解信息
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* BeanDefinitionRegistry:BeanDefinition注册类；
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* 把所有需要添加到容器中的bean；调用
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* BeanDefinitionRegistry.registerBeanDefinition手工注册进来
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*/
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@Override
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public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
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boolean definition = registry.containsBeanDefinition("com.atguigu.bean.Red");
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boolean definition2 = registry.containsBeanDefinition("com.atguigu.bean.Blue");
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if(definition && definition2){
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//指定Bean定义信息；（Bean的类型，Bean。。。）
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RootBeanDefinition beanDefinition = new RootBeanDefinition(RainBow.class);
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//注册一个Bean，指定bean名
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registry.registerBeanDefinition("rainBow", beanDefinition);
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}
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}
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}
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```
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```java
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public class Color {
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private Car car;
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public Car getCar() {
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return car;
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}
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public void setCar(Car car) {
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this.car = car;
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}
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@Override
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public String toString() {
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return "Color [car=" + car + "]";
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}
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}
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```
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```java
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public class Blue {
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public Blue(){
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System.out.println("blue...constructor");
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}
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public void init(){
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System.out.println("blue...init...");
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}
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public void detory(){
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System.out.println("blue...detory...");
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}
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}
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```
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|
||
|
||
|
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#### FactoryBean
|
||
|
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##### MainConfig2
|
||
|
||
```java
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@Configuration
|
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public class MainConfig2 {
|
||
|
||
|
||
/**
|
||
* 给容器中注册组件；
|
||
* 1）、包扫描+组件标注注解（@Controller/@Service/@Repository/@Component）[自己写的类]
|
||
* 2）、@Bean[导入的第三方包里面的组件]
|
||
* 3）、@Import[快速给容器中导入一个组件]
|
||
* 1）、@Import(要导入到容器中的组件)；容器中就会自动注册这个组件，id默认是全类名
|
||
* 2）、ImportSelector:返回需要导入的组件的全类名数组；
|
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* 3）、ImportBeanDefinitionRegistrar:手动注册bean到容器中
|
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* 4）、使用Spring提供的 FactoryBean（工厂Bean）;
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* 1）、默认获取到的是工厂bean调用getObject创建的对象
|
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* 2）、要获取工厂Bean本身，我们需要给id前面加一个&
|
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* &colorFactoryBean
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||
*
|
||
* 虽然这里装配的是ColorFactoryBean，但实际上beand的类型是Color
|
||
*/
|
||
@Bean
|
||
public ColorFactoryBean colorFactoryBean(){
|
||
return new ColorFactoryBean();
|
||
}
|
||
|
||
}
|
||
```
|
||
|
||
##### ColorFactoryBean
|
||
|
||
```java
|
||
//创建一个Spring定义的FactoryBean
|
||
public class ColorFactoryBean implements FactoryBean<Color> {
|
||
|
||
//返回一个Color对象，这个对象会添加到容器中
|
||
@Override
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||
public Color getObject() throws Exception {
|
||
// TODO Auto-generated method stub
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||
System.out.println("ColorFactoryBean...getObject...");
|
||
return new Color();
|
||
}
|
||
|
||
@Override
|
||
public Class<?> getObjectType() {
|
||
// TODO Auto-generated method stub
|
||
return Color.class;
|
||
}
|
||
|
||
//是单例？
|
||
//true：这个bean是单实例，在容器中保存一份
|
||
//false：多实例，每次获取都会创建一个新的bean；
|
||
@Override
|
||
public boolean isSingleton() {
|
||
// TODO Auto-generated method stub
|
||
return false;
|
||
}
|
||
|
||
}
|
||
```
|
||
|
||
##### IOCTest
|
||
|
||
```java
|
||
public class IOCTest {
|
||
AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(MainConfig2.class);
|
||
|
||
|
||
@Test
|
||
public void testImport(){
|
||
printBeans(applicationContext);
|
||
Blue bean = applicationContext.getBean(Blue.class);
|
||
System.out.println(bean);
|
||
|
||
//工厂Bean获取的是调用getObject创建的对象
|
||
Object bean2 = applicationContext.getBean("colorFactoryBean");
|
||
System.out.println("bean的类型："+bean2.getClass()); //pos_1 输出：bean的类型：class com.atguigu.bean.Color
|
||
|
||
Object bean4 = applicationContext.getBean("&colorFactoryBean");
|
||
System.out.println(bean4.getClass()); //pos_2 输出：class com.atguigu.bean.ColorFactoryBean
|
||
}
|
||
|
||
private void printBeans(AnnotationConfigApplicationContext applicationContext){
|
||
String[] definitionNames = applicationContext.getBeanDefinitionNames();
|
||
for (String name : definitionNames) {
|
||
System.out.println(name);
|
||
}
|
||
}
|
||
}
|
||
```
|
||
|
||
输出:
|
||
|
||
```java
|
||
//前面无关的输出省略
|
||
|
||
colorFactoryBean
|
||
ColorFactoryBean...getObject...
|
||
bean的类型：class com.atguigu.bean.Color
|
||
class com.atguigu.bean.ColorFactoryBean
|
||
```
|
||
|
||
|
||
|
||
### 生命周期
|
||
|
||
#### @Bean指定初始化和销毁方法
|
||
|
||
##### IOCTest_LifeCycle
|
||
|
||
> 后面的几个用的都是这个测试类
|
||
|
||
```java
|
||
public class IOCTest_LifeCycle {
|
||
|
||
@Test
|
||
public void test01(){
|
||
//1、创建ioc容器
|
||
AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(MainConfigOfLifeCycle.class);
|
||
System.out.println("容器创建完成...");
|
||
|
||
//applicationContext.getBean("car");
|
||
//关闭容器
|
||
applicationContext.close();
|
||
}
|
||
|
||
}
|
||
```
|
||
|
||
##### MainConfigOfLifeCycle
|
||
|
||
```java
|
||
package com.atguigu.config;
|
||
|
||
import org.springframework.context.ApplicationListener;
|
||
import org.springframework.context.annotation.Bean;
|
||
import org.springframework.context.annotation.ComponentScan;
|
||
import org.springframework.context.annotation.Configuration;
|
||
import org.springframework.context.annotation.Scope;
|
||
|
||
import com.atguigu.bean.Car;
|
||
|
||
/**
|
||
* bean的生命周期：
|
||
* bean创建---初始化----销毁的过程
|
||
* 容器管理bean的生命周期；
|
||
* 我们可以自定义初始化和销毁方法；容器在bean进行到当前生命周期的时候来调用我们自定义的初始化和销毁方法
|
||
*
|
||
* 构造（对象创建）
|
||
* 单实例：在容器启动的时候创建对象
|
||
* 多实例：在每次获取的时候创建对象\
|
||
* 初始化：
|
||
* 对象创建完成，并赋值好，调用初始化方法。。。
|
||
* BeanPostProcessor.postProcessAfterInitialization
|
||
* 销毁：
|
||
* 单实例：容器关闭的时候
|
||
* 多实例：容器不会管理这个bean；容器不会调用销毁方法；
|
||
*
|
||
* 1）、指定初始化和销毁方法；
|
||
* 通过@Bean指定init-method和destroy-method；
|
||
* @author lfy
|
||
*
|
||
*/
|
||
@ComponentScan("com.atguigu.bean")
|
||
@Configuration
|
||
public class MainConfigOfLifeCycle {
|
||
|
||
//@Scope("prototype")
|
||
@Bean(initMethod="init",destroyMethod="detory")
|
||
public Car car(){
|
||
return new Car();
|
||
}
|
||
|
||
}
|
||
```
|
||
|
||
|
||
|
||
```java
|
||
@Component
|
||
public class Car {
|
||
|
||
public Car(){
|
||
System.out.println("car constructor...");
|
||
}
|
||
|
||
public void init(){
|
||
System.out.println("car ... init...");
|
||
}
|
||
|
||
public void detory(){
|
||
System.out.println("car ... detory...");
|
||
}
|
||
|
||
}
|
||
```
|
||
|
||
##### 输出
|
||
|
||
```java
|
||
car constructor...
|
||
car ... init...
|
||
容器创建完成
|
||
car ... detory...
|
||
```
|
||
|
||
|
||
|
||
#### InitializingBean和DisposableBean
|
||
|
||
##### MainConfigOfLifeCycle
|
||
|
||
```java
|
||
/**
|
||
* bean的生命周期：
|
||
* bean创建---初始化----销毁的过程
|
||
* 容器管理bean的生命周期；
|
||
* 我们可以自定义初始化和销毁方法；容器在bean进行到当前生命周期的时候来调用我们自定义的初始化和销毁方法
|
||
*
|
||
* 构造（对象创建）
|
||
* 单实例：在容器启动的时候创建对象
|
||
* 多实例：在每次获取的时候创建对象\
|
||
*
|
||
* BeanPostProcessor.postProcessBeforeInitialization
|
||
* 初始化：
|
||
* 对象创建完成，并赋值好，调用初始化方法。。。
|
||
* BeanPostProcessor.postProcessAfterInitialization
|
||
* 销毁：
|
||
* 单实例：容器关闭的时候
|
||
* 多实例：容器不会管理这个bean；容器不会调用销毁方法；
|
||
*
|
||
*
|
||
* 遍历得到容器中所有的BeanPostProcessor；挨个执行beforeInitialization，
|
||
* 一但返回null，跳出for循环，不会执行后面的BeanPostProcessor.postProcessorsBeforeInitialization
|
||
*
|
||
* BeanPostProcessor原理
|
||
* populateBean(beanName, mbd, instanceWrapper);给bean进行属性赋值
|
||
* initializeBean
|
||
* {
|
||
* applyBeanPostProcessorsBeforeInitialization(wrappedBean, beanName);
|
||
* invokeInitMethods(beanName, wrappedBean, mbd);执行自定义初始化
|
||
* applyBeanPostProcessorsAfterInitialization(wrappedBean, beanName);
|
||
*}
|
||
*
|
||
*
|
||
*
|
||
* 1）、指定初始化和销毁方法；
|
||
* 通过@Bean指定init-method和destroy-method；
|
||
* 2）、通过让Bean实现InitializingBean（定义初始化逻辑），
|
||
* DisposableBean（定义销毁逻辑）;
|
||
*
|
||
* @author lfy
|
||
*
|
||
*/
|
||
@ComponentScan("com.atguigu.bean")
|
||
@Configuration
|
||
public class MainConfigOfLifeCycle {
|
||
|
||
//@Scope("prototype")
|
||
@Bean(initMethod="init",destroyMethod="detory")
|
||
public Car car(){
|
||
return new Car();
|
||
}
|
||
|
||
}
|
||
```
|
||
|
||
##### Cat
|
||
|
||
```java
|
||
@Component
|
||
public class Cat implements InitializingBean,DisposableBean {
|
||
|
||
public Cat(){
|
||
System.out.println("cat constructor...");
|
||
}
|
||
|
||
@Override
|
||
public void destroy() throws Exception {
|
||
// TODO Auto-generated method stub
|
||
System.out.println("cat...destroy...");
|
||
}
|
||
|
||
@Override
|
||
public void afterPropertiesSet() throws Exception {
|
||
// TODO Auto-generated method stub
|
||
System.out.println("cat...afterPropertiesSet...");
|
||
}
|
||
|
||
}
|
||
```
|
||
|
||
##### 输出
|
||
|
||
```java
|
||
cat constructor...
|
||
cat...afterPropertiesSet...
|
||
car constructor...
|
||
car ... init...
|
||
容器创建完成
|
||
car ... detory...
|
||
cat...destroy...
|
||
```
|
||
|
||
|
||
|
||
#### @PostConstruct和@PreDestroy
|
||
|
||
##### MainConfigOfLifeCycle
|
||
|
||
```java
|
||
/**
|
||
* bean的生命周期：
|
||
* bean创建---初始化----销毁的过程
|
||
* 容器管理bean的生命周期；
|
||
* 我们可以自定义初始化和销毁方法；容器在bean进行到当前生命周期的时候来调用我们自定义的初始化和销毁方法
|
||
*
|
||
* 构造（对象创建）
|
||
* 单实例：在容器启动的时候创建对象
|
||
* 多实例：在每次获取的时候创建对象\
|
||
*
|
||
* BeanPostProcessor.postProcessBeforeInitialization
|
||
* 初始化：
|
||
* 对象创建完成，并赋值好，调用初始化方法。。。
|
||
* BeanPostProcessor.postProcessAfterInitialization
|
||
* 销毁：
|
||
* 单实例：容器关闭的时候
|
||
* 多实例：容器不会管理这个bean；容器不会调用销毁方法；
|
||
*
|
||
*
|
||
* 遍历得到容器中所有的BeanPostProcessor；挨个执行beforeInitialization，
|
||
* 一但返回null，跳出for循环，不会执行后面的BeanPostProcessor.postProcessorsBeforeInitialization
|
||
*
|
||
* BeanPostProcessor原理
|
||
* populateBean(beanName, mbd, instanceWrapper);给bean进行属性赋值
|
||
* initializeBean
|
||
* {
|
||
* applyBeanPostProcessorsBeforeInitialization(wrappedBean, beanName);
|
||
* invokeInitMethods(beanName, wrappedBean, mbd);执行自定义初始化
|
||
* applyBeanPostProcessorsAfterInitialization(wrappedBean, beanName);
|
||
*}
|
||
*
|
||
*
|
||
*
|
||
* 1）、指定初始化和销毁方法；
|
||
* 通过@Bean指定init-method和destroy-method；
|
||
* 2）、通过让Bean实现InitializingBean（定义初始化逻辑），
|
||
* DisposableBean（定义销毁逻辑）;
|
||
* 3）、可以使用JSR250；
|
||
* @PostConstruct：在bean创建完成并且属性赋值完成；来执行初始化方法
|
||
* @PreDestroy：在容器销毁bean之前通知我们进行清理工作
|
||
*
|
||
* @author lfy
|
||
*
|
||
*/
|
||
@ComponentScan("com.atguigu.bean")
|
||
@Configuration
|
||
public class MainConfigOfLifeCycle {
|
||
|
||
//@Scope("prototype")
|
||
@Bean(initMethod="init",destroyMethod="detory")
|
||
public Car car(){
|
||
return new Car();
|
||
}
|
||
|
||
}
|
||
```
|
||
|
||
##### Dog
|
||
|
||
```java
|
||
@Component
|
||
public class Dog implements ApplicationContextAware {
|
||
|
||
//@Autowired
|
||
private ApplicationContext applicationContext;
|
||
|
||
public Dog(){
|
||
System.out.println("dog constructor...");
|
||
}
|
||
|
||
//对象创建并赋值之后调用
|
||
@PostConstruct
|
||
public void init(){
|
||
System.out.println("Dog....@PostConstruct...");
|
||
}
|
||
|
||
//容器移除对象之前
|
||
@PreDestroy
|
||
public void detory(){
|
||
System.out.println("Dog....@PreDestroy...");
|
||
}
|
||
|
||
@Override
|
||
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
|
||
// TODO Auto-generated method stub
|
||
this.applicationContext = applicationContext;
|
||
}
|
||
}
|
||
```
|
||
|
||
|
||
|
||
##### 输出
|
||
|
||
```java
|
||
cat constructor...
|
||
cat...afterPropertiesSet...
|
||
dog constructor...
|
||
Dog....@PostConstruct...
|
||
car constructor...
|
||
car ... init...
|
||
容器创建完成
|
||
car ... detory...
|
||
Dog....@PreDestroy...
|
||
cat...destroy...
|
||
```
|
||
|
||
|
||
|
||
#### BeanPostProcessor
|
||
|
||
```java
|
||
|
||
/**
|
||
* bean的生命周期：
|
||
* bean创建---初始化----销毁的过程
|
||
* 容器管理bean的生命周期；
|
||
* 我们可以自定义初始化和销毁方法；容器在bean进行到当前生命周期的时候来调用我们自定义的初始化和销毁方法
|
||
*
|
||
* 构造（对象创建）
|
||
* 单实例：在容器启动的时候创建对象
|
||
* 多实例：在每次获取的时候创建对象\
|
||
*
|
||
* BeanPostProcessor.postProcessBeforeInitialization
|
||
* 初始化：
|
||
* 对象创建完成，并赋值好，调用初始化方法。。。
|
||
* BeanPostProcessor.postProcessAfterInitialization
|
||
* 销毁：
|
||
* 单实例：容器关闭的时候
|
||
* 多实例：容器不会管理这个bean；容器不会调用销毁方法；
|
||
*
|
||
*
|
||
* 遍历得到容器中所有的BeanPostProcessor；挨个执行beforeInitialization，
|
||
* 一但返回null，跳出for循环，不会执行后面的BeanPostProcessor.postProcessorsBeforeInitialization
|
||
*
|
||
* BeanPostProcessor原理
|
||
* populateBean(beanName, mbd, instanceWrapper);给bean进行属性赋值
|
||
* initializeBean
|
||
* {
|
||
* applyBeanPostProcessorsBeforeInitialization(wrappedBean, beanName);
|
||
* invokeInitMethods(beanName, wrappedBean, mbd);执行自定义初始化
|
||
* applyBeanPostProcessorsAfterInitialization(wrappedBean, beanName);
|
||
*}
|
||
*
|
||
*
|
||
*
|
||
* 1）、指定初始化和销毁方法；
|
||
* 通过@Bean指定init-method和destroy-method；
|
||
* 2）、通过让Bean实现InitializingBean（定义初始化逻辑），
|
||
* DisposableBean（定义销毁逻辑）;
|
||
* 3）、可以使用JSR250；
|
||
* @PostConstruct：在bean创建完成并且属性赋值完成；来执行初始化方法
|
||
* @PreDestroy：在容器销毁bean之前通知我们进行清理工作
|
||
* 4）、BeanPostProcessor【interface】：bean的后置处理器；
|
||
* 在bean初始化前后进行一些处理工作；
|
||
* postProcessBeforeInitialization:在初始化之前工作
|
||
* postProcessAfterInitialization:在初始化之后工作
|
||
*
|
||
* Spring底层对 BeanPostProcessor 的使用；
|
||
* bean赋值，注入其他组件，@Autowired，生命周期注解功能，@Async,xxx BeanPostProcessor;
|
||
*
|
||
* @author lfy
|
||
*
|
||
*/
|
||
@ComponentScan("com.atguigu.bean")
|
||
@Configuration
|
||
public class MainConfigOfLifeCycle {
|
||
|
||
//@Scope("prototype")
|
||
@Bean(initMethod="init",destroyMethod="detory")
|
||
public Car car(){
|
||
return new Car();
|
||
}
|
||
|
||
}
|
||
```
|
||
|
||
##### MyBeanPostProcessor
|
||
|
||
```java
|
||
/**
|
||
* 后置处理器：初始化前后进行处理工作
|
||
* 将后置处理器加入到容器中
|
||
* @author lfy
|
||
*/
|
||
@Component
|
||
public class MyBeanPostProcessor implements BeanPostProcessor {
|
||
|
||
@Override
|
||
public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
|
||
// TODO Auto-generated method stub
|
||
System.out.println("postProcessBeforeInitialization..."+beanName+"=>"+bean);
|
||
return bean;
|
||
}
|
||
|
||
@Override
|
||
public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
|
||
// TODO Auto-generated method stub
|
||
System.out.println("postProcessAfterInitialization..."+beanName+"=>"+bean);
|
||
return bean;
|
||
}
|
||
|
||
}
|
||
```
|
||
|
||
输出
|
||
|
||
> 自己写的组件输出内容
|
||
|
||
```java
|
||
car constructor...
|
||
postProcessBeforeInitialization...car=>com.atguigu.bean.Car@5ef60048
|
||
car ... init...
|
||
postProcessAfterInitialization...car=>com.atguigu.bean.Car@5ef60048
|
||
cat constructor...
|
||
postProcessBeforeInitialization...cat=>com.atguigu.bean.Cat@780cb77
|
||
cat...afterPropertiesSet...
|
||
postProcessAfterInitialization...cat=>com.atguigu.bean.Cat@780cb77
|
||
dog constructor...
|
||
postProcessBeforeInitialization...dog=>com.atguigu.bean.Dog@4034c28c
|
||
Dog....@PostConstruct...
|
||
postProcessAfterInitialization...dog=>com.atguigu.bean.Dog@4034c28c
|
||
容器创建完成...
|
||
Dog....@PreDestroy...
|
||
cat...destroy...
|
||
car ... detory...
|
||
```
|
||
|
||
|
||
|
||
> 1. BeanPostProcessor在Spring源码里大量被使用到，仅凭这里雷丰阳老师讲的一点点原理，是无法体会的，建议自己去看看Spring源码。所以这里的原理部分我也就直接省略了，在本视频中讲的太浅了。
|
||
|
||
### 属性赋值
|
||
|
||
#### @Value和@PropertySource
|
||
|
||
##### Person
|
||
|
||
```java
|
||
public class Person {
|
||
|
||
//使用@Value赋值；
|
||
//1、基本数值
|
||
//2、可以写SpEL； #{}
|
||
//3、可以写${}；取出配置文件【properties】中的值（在运行环境变量里面的值）
|
||
|
||
@Value("张三")
|
||
private String name;
|
||
@Value("#{20-2}")
|
||
private Integer age;
|
||
|
||
@Value("${person.nickName}")
|
||
private String nickName;
|
||
|
||
|
||
|
||
public String getNickName() {
|
||
return nickName;
|
||
}
|
||
public void setNickName(String nickName) {
|
||
this.nickName = nickName;
|
||
}
|
||
public String getName() {
|
||
return name;
|
||
}
|
||
public void setName(String name) {
|
||
this.name = name;
|
||
}
|
||
public Integer getAge() {
|
||
return age;
|
||
}
|
||
public void setAge(Integer age) {
|
||
this.age = age;
|
||
}
|
||
|
||
public Person(String name, Integer age) {
|
||
super();
|
||
this.name = name;
|
||
this.age = age;
|
||
}
|
||
public Person() {
|
||
super();
|
||
// TODO Auto-generated constructor stub
|
||
}
|
||
@Override
|
||
public String toString() {
|
||
return "Person [name=" + name + ", age=" + age + ", nickName=" + nickName + "]";
|
||
}
|
||
}
|
||
```
|
||
|
||
##### person.properties
|
||
|
||
```java
|
||
person.nickName=\u5C0F\u674E\u56DB
|
||
```
|
||
|
||
|
||
|
||
##### MainConfigOfPropertyValues
|
||
|
||
```java
|
||
//使用@PropertySource读取外部配置文件中的k/v保存到运行的环境变量中;加载完外部的配置文件以后使用${}取出配置文件的值
|
||
@PropertySource(value={"classpath:/person.properties"})
|
||
@Configuration
|
||
public class MainConfigOfPropertyValues {
|
||
|
||
@Bean
|
||
public Person person(){
|
||
return new Person();
|
||
}
|
||
|
||
}
|
||
```
|
||
|
||
##### IOCTest_PropertyValue
|
||
|
||
```java
|
||
public class IOCTest_PropertyValue {
|
||
AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(MainConfigOfPropertyValues.class);
|
||
@Test
|
||
public void test01(){
|
||
printBeans(applicationContext);
|
||
System.out.println("=============");
|
||
|
||
Person person = (Person) applicationContext.getBean("person");
|
||
System.out.println(person);
|
||
|
||
|
||
ConfigurableEnvironment environment = applicationContext.getEnvironment();
|
||
String property = environment.getProperty("person.nickName");
|
||
System.out.println(property);
|
||
applicationContext.close();
|
||
}
|
||
|
||
private void printBeans(AnnotationConfigApplicationContext applicationContext){
|
||
String[] definitionNames = applicationContext.getBeanDefinitionNames();
|
||
for (String name : definitionNames) {
|
||
System.out.println(name);
|
||
}
|
||
}
|
||
|
||
}
|
||
```
|
||
|
||
##### 输出
|
||
|
||
```java
|
||
mainConfigOfPropertyValues
|
||
person
|
||
=============
|
||
Person [name=张三, age=18, nickName=小李四]
|
||
小李四
|
||
```
|
||
|
||
|
||
|
||
### 自动装配
|
||
|
||
#### @Autowired-@Qualifier-@Primary-@Resource-@Inject
|
||
|
||
```java
|
||
@Controller
|
||
public class BookController {
|
||
|
||
@Autowired
|
||
private BookService bookService;
|
||
|
||
}
|
||
```
|
||
|
||
|
||
|
||
```java
|
||
@Service
|
||
public class BookService {
|
||
|
||
//@Qualifier("bookDao")
|
||
//@Autowired(required=false)
|
||
//@Resource(name="bookDao2")
|
||
@Inject
|
||
private BookDao bookDao;
|
||
|
||
public void print(){
|
||
System.out.println(bookDao);
|
||
}
|
||
|
||
@Override
|
||
public String toString() {
|
||
return "BookService [bookDao=" + bookDao + "]";
|
||
}
|
||
|
||
|
||
}
|
||
```
|
||
|
||
|
||
|
||
```java
|
||
//名字默认是类名首字母小写
|
||
@Repository
|
||
public class BookDao {
|
||
|
||
private String lable = "1";
|
||
|
||
public String getLable() {
|
||
return lable;
|
||
}
|
||
|
||
public void setLable(String lable) {
|
||
this.lable = lable;
|
||
}
|
||
|
||
@Override
|
||
public String toString() {
|
||
return "BookDao [lable=" + lable + "]";
|
||
}
|
||
|
||
|
||
|
||
}
|
||
```
|
||
|
||
|
||
|
||
##### MainConifgOfAutowired
|
||
|
||
```java
|
||
/**
|
||
* 自动装配;
|
||
* Spring利用依赖注入（DI），完成对IOC容器中中各个组件的依赖关系赋值；
|
||
*
|
||
* 1）、@Autowired：自动注入：
|
||
* 1）、默认优先按照类型去容器中找对应的组件:applicationContext.getBean(BookDao.class);找到就赋值
|
||
* 2）、如果找到多个相同类型的组件，再将属性的名称作为组件的id去容器中查找
|
||
* applicationContext.getBean("bookDao")
|
||
* 3）、@Qualifier("bookDao")：使用@Qualifier指定需要装配的组件的id，而不是使用属性名
|
||
* 4）、自动装配默认一定要将属性赋值好，没有就会报错；
|
||
* 可以使用@Autowired(required=false);
|
||
* 5）、@Primary：让Spring进行自动装配的时候，默认使用首选的bean；
|
||
* 也可以继续使用@Qualifier指定需要装配的bean的名字
|
||
* BookService{
|
||
* @Autowired
|
||
* BookDao bookDao;
|
||
* }
|
||
*
|
||
* 2）、Spring还支持使用@Resource(JSR250)和@Inject(JSR330)[java规范的注解]
|
||
* @Resource:
|
||
* 可以和@Autowired一样实现自动装配功能；默认是按照组件名称进行装配的；
|
||
* 没有能支持@Primary功能没有支持@Autowired（reqiured=false）;
|
||
* @Inject:
|
||
* 需要导入javax.inject的包，和Autowired的功能一样。没有required=false的功能；
|
||
* @Autowired:Spring定义的； @Resource、@Inject都是java规范
|
||
*
|
||
* AutowiredAnnotationBeanPostProcessor:解析完成自动装配功能；
|
||
*
|
||
* 3）、 @Autowired:构造器，参数，方法，属性；都是从容器中获取参数组件的值
|
||
* 1）、[标注在方法位置]：@Bean+方法参数；参数从容器中获取;默认不写@Autowired效果是一样的；都能自动装配
|
||
* 2）、[标在构造器上]：如果组件只有一个有参构造器，这个有参构造器的@Autowired可以省略，参数位置的组件还是可以自动从容器中获取
|
||
* 3）、放在参数位置：
|
||
public Boss(@Autowired Car car){
|
||
this.car = car;
|
||
System.out.println("Boss...有参构造器");
|
||
}
|
||
*
|
||
* 4）、自定义组件想要使用Spring容器底层的一些组件（ApplicationContext，BeanFactory，xxx）；
|
||
* 自定义组件实现xxxAware；在创建对象的时候，会调用接口规定的方法注入相关组件；Aware；
|
||
* 把Spring底层一些组件注入到自定义的Bean中；
|
||
* xxxAware：功能使用xxxProcessor；
|
||
* ApplicationContextAware==》ApplicationContextAwareProcessor；
|
||
*
|
||
*
|
||
* @author lfy
|
||
*
|
||
*/
|
||
@Configuration
|
||
@ComponentScan({"com.atguigu.service","com.atguigu.dao",
|
||
"com.atguigu.controller","com.atguigu.bean"})
|
||
public class MainConifgOfAutowired {
|
||
|
||
@Primary
|
||
@Bean("bookDao2")
|
||
public BookDao bookDao(){
|
||
BookDao bookDao = new BookDao();
|
||
bookDao.setLable("2");
|
||
return bookDao;
|
||
}
|
||
|
||
/**
|
||
* @Bean标注的方法创建对象的时候，方法参数的值默认从容器中获取
|
||
* @param car
|
||
* @return
|
||
*/
|
||
@Bean
|
||
public Color color(Car car){
|
||
Color color = new Color();
|
||
color.setCar(car);
|
||
return color;
|
||
}
|
||
|
||
|
||
}
|
||
```
|
||
|
||
|
||
|
||
##### IOCTest_Autowired
|
||
|
||
```java
|
||
public class IOCTest_Autowired {
|
||
|
||
@Test
|
||
public void test01(){
|
||
AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(MainConifgOfAutowired.class);
|
||
|
||
BookService bookService = applicationContext.getBean(BookService.class);
|
||
System.out.println(bookService);
|
||
|
||
//BookDao bean = applicationContext.getBean(BookDao.class);
|
||
//System.out.println(bean);
|
||
|
||
Boss boss = applicationContext.getBean(Boss.class);
|
||
System.out.println(boss);
|
||
Car car = applicationContext.getBean(Car.class);
|
||
System.out.println(car);
|
||
|
||
Color color = applicationContext.getBean(Color.class);
|
||
System.out.println(color);
|
||
System.out.println(applicationContext);
|
||
applicationContext.close();
|
||
}
|
||
|
||
}
|
||
```
|
||
|
||
|
||
|
||
#### @Profle
|
||
|
||
##### MainConfigOfProfile
|
||
|
||
```java
|
||
/**
|
||
* Profile：
|
||
* Spring为我们提供的可以根据当前环境，动态的激活和切换一系列组件的功能；
|
||
*
|
||
* 开发环境、测试环境、生产环境；
|
||
* 数据源：(/A)(/B)(/C)；
|
||
*
|
||
*
|
||
* @Profile：指定组件在哪个环境的情况下才能被注册到容器中，不指定，任何环境下都能注册这个组件
|
||
*
|
||
* 1）、加了环境标识的bean，只有这个环境被激活的时候才能注册到容器中。默认是default环境
|
||
* 2）、写在配置类上，只有是指定的环境的时候，整个配置类里面的所有配置才能开始生效
|
||
* 3）、没有标注环境标识的bean在，任何环境下都是加载的；
|
||
*/
|
||
|
||
@PropertySource("classpath:/dbconfig.properties")
|
||
@Configuration
|
||
public class MainConfigOfProfile implements EmbeddedValueResolverAware{
|
||
|
||
@Value("${db.user}")
|
||
private String user;
|
||
|
||
private StringValueResolver valueResolver;
|
||
|
||
private String driverClass;
|
||
|
||
|
||
@Bean
|
||
public Yellow yellow(){
|
||
return new Yellow();
|
||
}
|
||
|
||
@Profile("test")
|
||
@Bean("testDataSource")
|
||
public DataSource dataSourceTest(@Value("${db.password}")String pwd) throws Exception{
|
||
ComboPooledDataSource dataSource = new ComboPooledDataSource();
|
||
dataSource.setUser(user);
|
||
dataSource.setPassword(pwd);
|
||
dataSource.setJdbcUrl("jdbc:mysql://localhost:3306/test");
|
||
dataSource.setDriverClass(driverClass);
|
||
return dataSource;
|
||
}
|
||
|
||
|
||
@Profile("dev")
|
||
@Bean("devDataSource")
|
||
public DataSource dataSourceDev(@Value("${db.password}")String pwd) throws Exception{
|
||
ComboPooledDataSource dataSource = new ComboPooledDataSource();
|
||
dataSource.setUser(user);
|
||
dataSource.setPassword(pwd);
|
||
dataSource.setJdbcUrl("jdbc:mysql://localhost:3306/ssm_crud");
|
||
dataSource.setDriverClass(driverClass);
|
||
return dataSource;
|
||
}
|
||
|
||
@Profile("prod")
|
||
@Bean("prodDataSource")
|
||
public DataSource dataSourceProd(@Value("${db.password}")String pwd) throws Exception{
|
||
ComboPooledDataSource dataSource = new ComboPooledDataSource();
|
||
dataSource.setUser(user);
|
||
dataSource.setPassword(pwd);
|
||
dataSource.setJdbcUrl("jdbc:mysql://localhost:3306/scw_0515");
|
||
|
||
dataSource.setDriverClass(driverClass);
|
||
return dataSource;
|
||
}
|
||
|
||
@Override
|
||
public void setEmbeddedValueResolver(StringValueResolver resolver) {
|
||
// TODO Auto-generated method stub
|
||
this.valueResolver = resolver;
|
||
driverClass = valueResolver.resolveStringValue("${db.driverClass}");
|
||
}
|
||
|
||
}
|
||
```
|
||
|
||
##### dbconfig.properties
|
||
|
||
```properties
|
||
db.user=root
|
||
db.password=123456
|
||
db.driverClass=com.mysql.jdbc.Driver
|
||
```
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|