Spring 方法注入

實現方法/手動模式

• Java 註解配置元信息

  • @Autowired
  • @Resource
  • @Inject(可選)
  • @Bean

@Autowired 只按照byType 注入,由Spring提供

---

@Resource 默認按byName自動注入，也提供按照byType 注入,由JDK提供

---

// @Inject 須要依賴

<dependency>
            <groupId>javax.inject</groupId>
            <artifactId>javax.inject</artifactId>
            <version>1</version>
</dependency>

實體類Holder.java

package com.rumenz;

public class Holder {

    private Rumenz rumenz;

    public Holder(Rumenz rumenz) {
        this.rumenz = rumenz;
    }

    public Rumenz getRumenz() {
        return rumenz;
    }

    public void setRumenz(Rumenz rumenz) {
        this.rumenz = rumenz;
    }
}

實體類Rumenz.java

package com.rumenz;

public class Rumenz {

    private Integer id;
    private String name;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

配置文件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"
       xmlns:util="http://www.springframework.org/schema/util"
       xsi:schemaLocation="
        http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/util https://www.springframework.org/schema/util/spring-util.xsd">
    <bean id="rumenz" class="com.rumenz.Rumenz">
        <property name="id" value="123"/>
        <property name="name" value="入門小站"/>
    </bean>
</beans>

調用

package com.rumenz;


import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.support.BeanDefinitionBuilder;
import org.springframework.beans.factory.support.DefaultListableBeanFactory;
import org.springframework.beans.factory.xml.XmlBeanDefinitionReader;
import org.springframework.beans.factory.xml.XmlReaderContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.Bean;

import javax.annotation.Resource;
import javax.inject.Inject;

public class DemoApplication {


    private Holder holder;


    private Holder holder1;

    private Holder holder2;


    @Autowired
    public void init(Holder holder){
        this.holder=holder;
    }

    @Resource
    public void init1(Holder holder){
        this.holder1=holder;
    }

    @Inject
    public void init2(Holder holder){
        this.holder2=holder;
    }

    public static void main(String[] args) {
        AnnotationConfigApplicationContext ac=new AnnotationConfigApplicationContext();

        XmlBeanDefinitionReader xr=new XmlBeanDefinitionReader(ac);
        xr.loadBeanDefinitions("Beans.xml");

        ac.register(DemoApplication.class);
        ac.refresh();
        DemoApplication bean = ac.getBean(DemoApplication.class);
        System.out.println(bean.holder.getRumenz().getName());
        System.out.println(bean.holder1.getRumenz().getName());
        System.out.println(bean.holder2.getRumenz().getName());
        ac.close();
    }

    @Bean
    public Holder holder(Rumenz rumenz){
        return new Holder(rumenz);
    }

}

輸出

入門小站
入門小站
入門小站

原文: https://rumenz.com/rumenbiji/Spring-function-injection.html