Spring 基于Java的Bean声明

Spring 基于Java的Bean声明

使用@Configuration进行设置；

Xml：

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.springframework.org/schema/beans"

    xmlns:p="http://www.springframework.org/schema/p" xmlns:util="http://www.springframework.org/schema/util"

    xmlns:context="http://www.springframework.org/schema/context"

    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd

        http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.1.xsd

        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd">

    <context:component-scan base-package="com.stono.sprtest"></context:component-scan>

</beans>

JavaConfig：

package com.stono.sprtest;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Configuration;

import org.springframework.context.annotation.Scope;

@Configuration

public class SingerConfig {

    @Bean

    @Scope("prototype")

    // 如果加了这个就会导致有两个Cymbal对象；

    public InstrumentI cymbal() {

        return new Cymbal();

    }

    @Bean

    public Singer3 singer3() {

        // 参数里面的cymbal()不会新建Bean，还是之前那个单例实体；

        return new Singer3(cymbal(), "newstr");

    }

}

AppBean：

package com.stono.sprtest;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class AppBeans8 {

    @SuppressWarnings("resource")

    public static void main(String[] args) {

        ApplicationContext context = new ClassPathXmlApplicationContext("appbeans8.xml");

        Singer3 singer3 = (Singer3) context.getBean("singer3");

        System.out.println(singer3);

        Object bean = context.getBean("cymbal");

        System.out.println(bean);

    }

}

POJO：

package com.stono.sprtest;

import org.springframework.beans.factory.annotation.Autowired;

public class Singer3 {

    @Autowired

    private InstrumentI instrument;

    private String name;

    public Singer3(InstrumentI instrument, String name) {

        this.instrument = instrument;

        this.name = name;

    }

    @Override

    public String toString() {

        return "Singer2 [instrument=" + instrument + ", name=" + name + "]";

    }

}

package com.stono.sprtest;

public class Cymbal implements InstrumentI {

}