Spring注解开发——2、组件注册[email protected]&@Bean给容器中注册组件

1、xml方式 注册Bean

1 、新建 Pension.java 实体类

package com.suirui.springanno.entity;

public class Person {

    public Person() {
    }

    String name;
    int age;

    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 Person(String name, int age) {
        this.name = name;
        this.age = age;
    }

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

2、 resource目录下新建 beans.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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

    <bean id="persion" class="com.hw.springannotation.beans.Persion">
        <property name="name" value="hw"></property>
        <property name="age" value="18"></property>
    </bean>
</beans>

3 创建MainTest 测试类,运行，打印pension信息。

package com.suirui.springanno;


import com.suirui.springanno.config.MainConfig;
import com.suirui.springanno.entity.Person;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MainTest {
    public static void main(String[] args) {
        /**
         * 配置文件的方式
         */
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("beans.xml");
        Person pension = (Person) applicationContext.getBean("xmlBeanPerson");
        System.out.println(pension);

//        AnnotationConfigApplicationContext ac = new AnnotationConfigApplicationContext(MainConfig.class);
//        Person person = ac.getBean(Person.class);
//        System.out.println(person);
    }
}

2、注解方式注册组件

1 添加MainConfig.class 配置类，如下：

package com.suirui.springanno.config;

import com.suirui.springanno.entity.Person;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration  //告诉Spring这是一个配置类
public class MainConfig {

    @Bean("personAnno") //给容器注册一个bean，类型为返回值类型，id默认是方法名,可以通过注解value替换名称
    public Person person() {
       return  new Person("zx",28);
    }

}

2 创建test测试类，运行

package com.suirui.springanno;


import com.suirui.springanno.config.MainConfig;
import com.suirui.springanno.entity.Person;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MainTest {
    public static void main(String[] args) {
//        /**
//         * 配置文件的方式
//         */
//        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("beans.xml");
//        Person pension = (Person) applicationContext.getBean("xmlBeanPerson");
//        System.out.println(pension);

        AnnotationConfigApplicationContext ac = new AnnotationConfigApplicationContext(MainConfig.class);
        Person person = ac.getBean(Person.class);//获取所有的该类型的bean
        System.out.println(person);
        String[] beanNamesForType = ac.getBeanNamesForType(Person.class);//获取所有的该类型的bean名称
        for (String s : beanNamesForType) {
            System.out.println(s);
        }
    }
}