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java开发两年，连Spring中bean的装配都不知道？你怎么涨薪啊
阅读原文时间：2022年01月18日阅读：1

1.1.1.1 创建一个bean

package com.zt.spring;

public class MyBean {

private String userName;

private Integer userAge;

}

1.1.1.2 配置Config 配置bean

package com.zt.spring;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class MyBeanConfig {
// 和xml中配置文件的bean的标签是一样的
@Bean(name = "beanName")
public MyBean createBean(){
return new MyBean();
}
}

1.1.1.3 配置bean 单例还是多例的

package com.zt.spring;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Scope;

@Configuration
public class MyBeanConfig {

@Bean(name = "beanName")  
// 默认值是多例的  xml的方式可以在bean的标签上面  设置这个参数  
@Scope("prototype")  
public MyBean createBean(){  
    return new MyBean();  
}

}

1.1.1.4 获取上文，获取bean

package com.zt.spring;

import org.springframework.context.annotation.AnnotationConfigApplicationContext;

public class App {
public static void main(String[] args) {
// 获取上下文
AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(MyBeanConfig.class);
// 通过bean的那么获取bean
System.out.println(context.getBean("beanName"));
// 获取bean的class文件获取
System.out.println(context.getBean(MyBean.class));
context.close();
}
}

1.1.2 通过FactoryBean实现bena的装配

1.1.2.1 创建一个bean

package com.zt.spring;

public class Car {
}

1.1.2.2 配置Config 配置bean

package com.zt.spring;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class MyBeanConfig {

@Bean  
public CarFactoryBean createRunnableFactoryBean() {  
    return new CarFactoryBean();  
}

}

1.1.2.3 配置FactoryBean 生产bean

package com.zt.spring;

import org.springframework.beans.factory.FactoryBean;

public class CarFactoryBean implements FactoryBean {

//获取到对应的实体  
@Override  
public Car getObject() throws Exception {  
    return new Car();  
}

// 返回的额对应的是class文件  
@Override  
public Class<?> getObjectType() {  
    return Car.class;  
}

//配置是不是单例  
@Override  
public boolean isSingleton() {  
    return true;  
}

}

1.1.2.4 获取上文，获取bean

package com.zt.spring;

import org.springframework.context.annotation.AnnotationConfigApplicationContext;

public class App {
public static void main(String[] args) {
// 获取上下文
AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(MyBeanConfig.class);
// 通过FactoryBean 创建的bean
System.out.println(context.getBean(Car.class));
// 通过name获取car的实体
System.out.println(context.getBean("createRunnableFactoryBean"));
context.close();
}
}

1.1.3 通过另外一种工工厂模式实现bena的装配

1.1.3.1 创建一个bean

package com.zt.spring;

public class Jeep {
}

1.1.3.2 配置Config 配置bean

package com.zt.spring;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class MyBeanConfig {

@Bean  
public JeepFactory createJeepFactory() {  
    return new JeepFactory();  
}

@Bean  
public Jeep createJeep(JeepFactory factory) {  
    return factory.creat();  
}

}

1.1.3.3 创建 Factory 实现构建方法

package com.zt.spring;

public class JeepFactory {

public Jeep creat() {  
    return new Jeep();  
}

}

1.1.3.4 获取上文，获取bean

package com.zt.spring;

import org.springframework.context.annotation.AnnotationConfigApplicationContext;

public class App {
public static void main(String[] args) {
// 获取上下文
AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(MyBeanConfig.class);
System.out.println(context.getBean("createJeep"));
System.out.println(context.getBean(Jeep.class));
context.close();
}
}

1.2.1 调用spring自己的初始化和销毁的方法

1.2.1.1 创建一个bean

并且继承InitializingBean, DisposableBean ,实现afterPropertiesSet，destroy方法

package com.zt.spring;

import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;

public class User implements InitializingBean, DisposableBean {

@Override  
public void afterPropertiesSet() throws Exception {  
    System.out.println("=======afterPropertiesSet========");  
}

@Override  
public void destroy() throws Exception {  
    System.out.println("=======destroy========");  
}

}

1.2.1.2在conffig文件中装配这个bean

package com.zt.spring;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class MyBeanConfig {

@Bean  
public User createUser() {  
    return new User();  
}

}

1.2.1.3 获取上下文

package com.zt.spring;

import org.springframework.context.annotation.AnnotationConfigApplicationContext;

public class App {
public static void main(String[] args) {
// 获取上下文
AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(MyBeanConfig.class);
System.out.println(context.getBean(User.class));
context.close();
}
}

1.2.2 调用自定义初始化和销毁的方法

1.2.2.1 创建一个bean

自定义init，destroy方法

package com.zt.spring;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class MyBeanConfig {

@Bean(initMethod = "init",destroyMethod = "destroy")  
public Dog createDog() {  
    return new Dog();  
}

}

1.2.2.2在conffig文件中装配这个bean

package com.zt.spring;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class MyBeanConfig {

@Bean(initMethod = "init",destroyMethod = "destroy")  
public Dog createDog() {  
    return new Dog();  
}

}

1.2.2.3 获取上下文

package com.zt.spring;

import org.springframework.context.annotation.AnnotationConfigApplicationContext;

public class App {
public static void main(String[] args) {
// 获取上下文
AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(MyBeanConfig.class);
System.out.println(context.getBean(Dog.class));
context.close();
}
}

1.2.3 调用自定义并且注解初始化和销毁的方法

1.2.3.1 创建一个bean

自定义init，destroy方法  在加上注解放 @PostConstruct， @PreDestroy的方式实现

package com.zt.spring;

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;

public class UserInfo {

@PostConstruct  
public void afterPropertiesSet() throws Exception {  
    System.out.println("=======afterPropertiesSet========");  
}

@PreDestroy  
public void destroy() throws Exception {  
    System.out.println("=======destroy========");  
}

}

1.2.3.2在conffig文件中装配这个bean

package com.zt.spring;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class MyBeanConfig {
@Bean
public UserInfo createUserInfo() {
return new UserInfo();
}
}

1.2.2.3 获取上下文

package com.zt.spring;

import org.springframework.context.annotation.AnnotationConfigApplicationContext;

public class App {
public static void main(String[] args) {
// 获取上下文
AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(MyBeanConfig.class);
System.out.println(context.getBean(UserInfo.class));
context.close();
}
}

1.4 pom.文件


http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
4.0.0

<groupId>com..zt</groupId>  
<artifactId>spring</artifactId>  
<version>1.0-SNAPSHOT</version>

<properties>  
    <project.build.sourceEncodding>UTF-8</project.build.sourceEncodding>  
    <maven.compiler.source>1.8</maven.compiler.source>  
    <maven.compiler.target>1.8</maven.compiler.target>  
</properties>

<dependencies>  
    <dependency>  
        <groupId>org.springframework</groupId>  
        <artifactId>spring-context</artifactId>  
        <version>4.3.20.RELEASE</version>  
    </dependency>  
</dependencies>

感谢你看到这里，说的都是自己的一些看法和见解，如有不对，请指正！觉得文章对你有帮助的话不妨给我点个赞，每天都会分享java相关技术文章或行业资讯，欢迎大家关注和转发文章！

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