1.8.1 使用BeanPostProcessor客制化bean 可以定义多个BeanPostProcessor实例， 也可以控制执行的顺序通过 order的属性。 实例： package scripting; import org.springframework.beans.factory.config.BeanPostProcessor; public class InstantiationTracingBeanPostProcessor implements BeanPostProcessor { // simply return the instantiated bean as-is public Object postProcessBeforeInitialization(Object bean, String beanName) { return bean; // we could potentially return any object reference here... } public Object postProcessAfterInitialization(Object bean, String beanName) { System.out.println("Bean '" + beanName + "' created : " + bean.toString()); return bean; } } } <?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:lang="http://www.springframework.org/schema/lang" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/lang http://www.springframework.org/schema/lang/spring-lang.xsd"> <lang:groovy id="messenger" script-source="classpath:org/springframework/scripting/groovy/Messenger.groovy"> <lang:property name="message" value="Fiona Apple Is Just So Dreamy."/> </lang:groovy> <!-- when the above bean (messenger) is instantiated, this custom BeanPostProcessor implementation will output the fact to the system console --> <bean class="scripting.InstantiationTracingBeanPostProcessor"/> </beans> 在Bean初始化之后会执行 com.oscar999.chp1.section8.InstantiationTracingBeanPostProcessor 1.8.2 使用BeanFactoryPostProcessor配置元数据 BeanFactoryPostProcessors 可以配置多个， 可以通过order属性控制执行顺序。 常用jdbc 配置 <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"> <property name="locations" value="classpath:com/foo/jdbc.properties"/> </bean> <bean id="dataSource" destroy-method="close" class="org.apache.commons.dbcp.BasicDataSource"> <property name="driverClassName" value="${jdbc.driverClassName}"/> <property name="url" value="${jdbc.url}"/> <property name="username" value="${jdbc.username}"/> <property name="password" value="${jdbc.password}"/> </bean> PropertyPlaceholderConfigurer 如果在文件中没找到的话， 会找java的系统属性。可以通过设置systemPropertiesMode 属性来设定此行为： never (0): 不检查系统属性 fallback (1):默认配置， 没找到文件，找系统属性 override (2): 先找系统属性，再找文件 系统属性可以覆盖其他属性设置。 <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"> <property name="locations"> <value>classpath:com/foo/strategy.properties</value> </property> <property name="properties"> <value>custom.strategy.class=com.foo.DefaultStrategy</value> </property> </bean> <bean id="serviceStrategy" class="${custom.strategy.class}"/> PropertyOverrideConfigurer也可以用来设置属性值。 1.8.3 使用FactoryBean定制实例化 getObject() isSingleton() getObjectType()