显示目录

Autowired 注入

@Autowired 是基于类型的注入,Spring 会在 IoC 容器里查找类型匹配的 Bean 注入。

spring-beans.xml

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<?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:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd">
<context:component-scan base-package="com.xtuer.beans"/>
<bean class="com.xtuer.beans.Door"/>
</beans>

Door

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package com.xtuer.beans;
public class Door {
private String description;
public Door() {
description = "Default Door";
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
}

House

使用 @Autowired 注入 door。

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package com.xtuer.beans;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
// 生成的 Bean 的 ID 是 house
@Component
public class House {
private String description;
@Autowired
private Door door;
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public Door getDoor() {
return door;
}
public void setDoor(Door door) {
this.door = door;
}
}

测试

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import com.xtuer.beans.House;
import com.xtuer.util.CommonUtils;
import org.junit.Assert;
import org.junit.BeforeClass;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class ComponentScanTest {
private static ApplicationContext context;
@BeforeClass
public static void setup() {
context = new ClassPathXmlApplicationContext("spring-beans.xml");
}
@Test
public void test() {
House house1 = context.getBean(House.class);
CommonUtils.output(house1);
}
}

输出

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{
"description" : null,
"door" : {
"description" : "Default Door"
}
}