Spring实战（第4版） Spring Inaction 笔记(第一章）依赖注入和AOP

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源码地址 https://manning-content.s3.amazonaws.com/download/9/ef4e0ef-b7bd-4ab8-857d-eb635d18d425/SpringiA4_SourceCode.zip

java依赖注入（Dependency Injection)

方法一,使用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"  xsi:schemaLocation="http://www.springframework.org/schema/beans       http://www.springframework.org/schema/beans/spring-beans.xsd">  <bean id="knight" class="sia.knights.BraveKnight">    <constructor-arg ref="quest" />  </bean>  <!--System.out是一个PrintStream-->  <bean id="quest" class="sia.knights.SlayDragonQuest">    <constructor-arg value="#{T(System).out}" />  </bean></beans>

方法二。使用json

import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import sia.knights.BraveKnight;import sia.knights.Knight;import sia.knights.Quest;import sia.knights.SlayDragonQuest;@Configurationpublic class KnightConfig {  @Bean  public Knight knight() {    return new BraveKnight(quest());  }    @Bean  public Quest quest() {    return new SlayDragonQuest(System.out);  }}

两者完全等价

使用。

import org.springframework.context.annotation.AnnotationConfigApplicationContext;import org.springframework.context.support.                   ClassPathXmlApplicationContext;import sia.knights.config.KnightConfig;public class KnightMain {  public static void main(String[] args) throws Exception {    ClassPathXmlApplicationContext contextXml =        new ClassPathXmlApplicationContext(            "META-INF/spring/knight.xml");    AnnotationConfigApplicationContext contextJava = new AnnotationConfigApplicationContext(KnightConfig.class);    Knight knight = contextXml.getBean(Knight.class);    knight.embarkOnQuest();    contextXml.close();  }}

将contextJava完全替换即可运行，如果多个配置类。用,分隔

JAVA切面(aop, aspect-oriented programming)

<?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:aop="http://www.springframework.org/schema/aop"  xsi:schemaLocation="http://www.springframework.org/schema/aop       http://www.springframework.org/schema/aop/spring-aop.xsdhttp://www.springframework.org/schema/beans       http://www.springframework.org/schema/beans/spring-beans.xsd">  <bean id="knight" class="sia.knights.BraveKnight">    <constructor-arg ref="quest" />  </bean>  <bean id="quest" class="sia.knights.SlayDragonQuest">    <constructor-arg value="#{T(System).out}" />  </bean>  <bean id="minstrel" class="sia.knights.Minstrel">    <constructor-arg value="#{T(System).out}" />  </bean>  <aop:config>    <aop:aspect ref="minstrel">      <aop:pointcut id="embark"          expression="execution(* *.embarkOnQuest(..))"/>      <!--  这里定义了一个切面minstrel， 在方法 embarkOnQuest 之前和之后。分别执行singBeforeQuest和singAfterQuest-->              <aop:before pointcut-ref="embark"           method="singBeforeQuest"/>      <!--  System.out是一个PrintStream  -->            <aop:after pointcut-ref="embark"           method="singAfterQuest"/>    </aop:aspect>  </aop:config>  </beans>

第一章结束

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