Spring的《XML显式装配bean》- 默认自动装配

水深无声 2022-07-11 09:22 140阅读 0赞

> 这一blog主要介绍如何在XML中配置默认的自动装配机制

前面两节讲自动装配都是在单独的bean中配置，默认自动装配则是设置在beans 标签里面，表示当前xml默认的自动装配原则：

<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:util="http://www.springframework.org/schema/util" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-2.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.1.xsd http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.0.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd" default-autowire="byName">
    
        <bean id="blueberryCheeseCake" class="spring.ch2.topic2.Cake" p:name="blueberryCheeseCake" scope="prototype" />
    
        <bean id="jack" class="spring.ch2.topic2.Chief" p:name="jack" autowire="constructor" />
    </beans>

（1）上面再beans标签的最后有一个default-autowire=”byName” 这个标签代表的是这个配置文件里面所有的bean，将优先以这种方式装配，例如上面的byName

（2）当bean里面和头文件里面同时出现autowire，以bean的设置为优先。