Dynamic Language Support

<beans>

	<!-- this bean is now 'refreshable' due to the presence of the 'refresh-check-delay' attribute -->
	<lang:groovy id="messenger"
			refresh-check-delay="5000" <!-- switches refreshing on with 5 seconds between checks -->
			script-source="classpath:Messenger.groovy">
		<lang:property name="message" value="I Can Do The Frug" />
	</lang:groovy>

	<bean id="bookingService" class="x.y.DefaultBookingService">
		<property name="messenger" ref="messenger" />
	</bean>

</beans>

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.scripting.Messenger;

public final class Boot {

	public static void main(final String[] args) throws Exception {
		ApplicationContext ctx = new ClassPathXmlApplicationContext("beans.xml");
		Messenger messenger = (Messenger) ctx.getBean("messenger");
		System.out.println(messenger.getMessage());
		// pause execution while I go off and make changes to the source file...
		System.in.read();
		System.out.println(messenger.getMessage());
	}
}

class GroovyMessenger implements Messenger {

	private String message = "Bingo"

	public String getMessage() {
		// change the implementation to surround the message in quotes
		return "'" + this.message + "'"
	}

	public void setMessage(String message) {
		this.message = message
	}
}

<lang:groovy id="messenger">
	<lang:inline-script>

		package org.springframework.scripting.groovy

		import org.springframework.scripting.Messenger

		class GroovyMessenger implements Messenger {
			String message
		}

	</lang:inline-script>
	<lang:property name="message" value="I Can Do The Frug" />
</lang:groovy>

import org.springframework.scripting.Messenger

// from the file 'Messenger.groovy'
class GroovyMessenger implements Messenger {

	GroovyMessenger() {}

	// this constructor is not available for Constructor Injection
	GroovyMessenger(String message) {
		this.message = message;
	}

	String message

	String anotherMessage
}

<lang:groovy id="badMessenger"
	script-source="classpath:Messenger.groovy">
	<!-- this next constructor argument will not be injected into the GroovyMessenger -->
	<!-- in fact, this isn't even allowed according to the schema -->
	<constructor-arg value="This will not work" />

	<!-- only property values are injected into the dynamic-language-backed object -->
	<lang:property name="anotherMessage" value="Passed straight through to the dynamic-language-backed object" />

</lang>

public interface GroovyObjectCustomizer {

	void customize(GroovyObject goo);
}

public final class SimpleMethodTracingCustomizer implements GroovyObjectCustomizer {

	public void customize(GroovyObject goo) {
		DelegatingMetaClass metaClass = new DelegatingMetaClass(goo.getMetaClass()) {

			public Object invokeMethod(Object object, String methodName, Object[] arguments) {
				System.out.println("Invoking '" + methodName + "'.");
				return super.invokeMethod(object, methodName, arguments);
			}
		};
		metaClass.initialize();
		goo.setMetaClass(metaClass);
	}

}

<!-- define the GroovyObjectCustomizer just like any other bean -->
<bean id="tracingCustomizer" class="example.SimpleMethodTracingCustomizer"/>

	<!-- ... and plug it into the desired Groovy bean via the 'customizer-ref' attribute -->
	<lang:groovy id="calculator"
		script-source="classpath:org/springframework/scripting/groovy/Calculator.groovy"
		customizer-ref="tracingCustomizer"/>

<bean id="calculator" class="org.springframework.scripting.groovy.GroovyScriptFactory">
	<constructor-arg value="classpath:org/springframework/scripting/groovy/Calculator.groovy"/>
	<!-- define the GroovyObjectCustomizer (as an inner bean) -->
	<constructor-arg>
		<bean id="tracingCustomizer" class="example.SimpleMethodTracingCustomizer"/>
	</constructor-arg>
</bean>

<bean class="org.springframework.scripting.support.ScriptFactoryPostProcessor"/>