1.8.1 使用BeanPostProcessor客制化bean 可以定義多個BeanPostProcessor實例， 也可以控制執行的順序通過 order的屬性。 實例： 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初始化之后會執行 com.oscar999.chp1.section8.InstantiationTracingBeanPostProcessor 1.8.2 使用BeanFactoryPostProcessor配置元數據 BeanFactoryPostProcessors 可以配置多個， 可以通過order屬性控制執行順序。 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 如果在文件中沒找到的話， 會找java的系統屬性。可以通過設置systemPropertiesMode?屬性來設定此行為： never?(0):?不檢查系統屬性 fallback?(1):默認配置， 沒找到文件，找系統屬性 override?(2):?先找系統屬性，再找文件 系統屬性可以覆蓋其他屬性設置。 <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也可以用來設置屬性值。 1.8.3 使用FactoryBean定制實例化 getObject() isSingleton() getObjectType()