spring in action 2.0读书笔记(3)

spring in action 2.0读书笔记(三)

<bean id="baseSaxophonist" ref="saxophone" /><property name="song" value="Jingle Bells" /></bean><bean id="kenny" parent="baseSaxophonist" /><bean id="david" parent="baseSaxophonist" />

Spring inheritance(different from Java inheritance)： abstract and parent, is commonly used to reduce the amount of redundant XML. e.g: TransactionProxyFactoryBean.

Spring提供了method injection功能，使你能够在runtime期间把method注入到class里.Spring提供了2种方式的method injection：
1．Method replacement—Enables existing methods (abstract or concrete) to be replaced at runtime with new implementations.

<bean id="magicBox"    replacer="tigerReplacer" /></bean> <bean id="tigerReplacer" /> import org.springframework.beans.factory.support.MethodReplacer;public class TigerReplacer implements MethodReplacer {    public Object reimplement(Object target, Method method,        Object[] args) throws Throwable {            return "A ferocious tiger";    }}

2．Getter injection—Enables existing methods (abstract or concrete) to be replaced at runtime with a new implementation that returns a specific bean from the Spring context. （这种方式是for"使用get开头的，而且返回值是在spring里有bean定义类型"的方法）

<bean id="stevie"    bean="guitar" /></bean>

There’s no need to write a MethodReplacer class.

Injecting non-Spring beans
对于在spring里有定义bean，但又不是通过spring来创建的class，又应该如何使用spring呢？这种情况是可能的：例如，一个由ORM创建的object则不是spring创建的。
第一步：把bean定义成abstract:

<bean id="pianist"    />        </property></bean>

第二步：如果把上面的定义（注意上面设置的id）和class联系起来

@Configurable("pianist")public class Instrumentalist implements Performer {…}

@Configurable的作用有2个：
1> 它表明Instrumentalist的实例会被纳入和配置到spring container里，即使它是在outside of spring创建。
2> 它把Instrumentalist class与id为pianist联系在一起，当spring在配置一个实例时，它会寻找pianist bean作为模板来进行配置（包括DI）
第三步：在spring configure file里添加下列代码

<aop:spring-configured />

它表示有一些在外部创建的beans，需要被配置和纳入进spring container.
请注意：<aop:spring-configured/>是用到aspectJ，这意味着你的APP必须在一个AspectJ-enabled JVM里运行。
The best way to AspectJ-enable a Java 5 JVM is to start it with the following JVM argument:
-javaagent:/path/to/aspectjweaver.jar

Registering custom property editors
extends java.beans.PropertyEditorSupport

public class PhoneEditor    extends java.beans.PropertyEditorSupport {    //text value example “111-111-111”    public void setAsText(String textValue) {       String areaCode = textValue.substring(0,3);       String prefix = textValue.substring(4,7);       String number = textValue.substring(8);       PhoneNumber phone = new PhoneNumber(areaCode, prefix, number);       setValue(phone);    }}<bean name="code"><bean id="propertyConfigurer" value="jdbc.properties" /></bean><bean id="dataSource"value="${database.url}" />    <property name="driverClassName" value="${database.driver}" />    <property name="username" value="${database.user}" />    <property name="password" value="${database.password}" /></bean>

Resolving resource messages

<bean id="messageSource"name="code">class HeartbeatForwarder implements ApplicationListener {　public void onApplicationEvent(ApplicationEvent event) {　　if (event instanceof HeartbeatEvent) {　　　System.out.println("Received heartbeat event: " + event.getTimestamp());　　}　}}

第三步：在spring里注册该listener。
第四步: 用来publish event的bean,因为publish event需要用到applicationcontext,所以implements ApplicationContextAware

class HeartbeatTask extends TimerTask implements ApplicationEventPublisherAware {　private ApplicationEventPublisher eventPublisher;　public void run() {　　HeartbeatEvent event = new HeartbeatEvent(this);　　eventPublisher.publishEvent(event);　}　public void setApplicationEventPublisher(ApplicationEventPublisher eventPublisher) {　　this.eventPublisher = eventPublisher;　}}

Scripting beans
把script bean注入到java class bean

<lang:jruby id="lime"    script-source="classpath:com/springinaction/scripting/Lime.rb"    script-interfaces="com.springinaction.scripting.Lime" />

把java class bean注入到script bean

<lang:groovy id="coconut"script-source="classpath:com/springinaction/scripting/Coconut.groovy">       <lang:property name="lime" ref="lime" /></lang:groovy>

Refreshing scripted beans

<lang:jruby id="lime"script-source="classpath:com/springinaction/scripting/Lime.rb"script-interfaces="com.springinaction.scripting.Lime"refresh-check-delay="5000"/>

Writing scripted beans inline

<lang:bsh id="lime"    script-interfaces="com.springinaction.scripting.Lime"><lang:inline-script><![CDATA[void drink() {System.out.println("Called the doctor woke him up!");}]]></lang:inline-script></lang:bsh>

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