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 {
}