@Target(value=TYPE) @Retention(value=RUNTIME) @Documented @Import(value=LoadTimeWeavingConfiguration.class) public @interface EnableLoadTimeWeaving
LoadTimeWeaver
for this application context, available as
a bean with the name "loadTimeWeaver", similar to the <context:load-time-weaver>
element in Spring XML.
To be used
on @Configuration
classes;
the simplest possible example of which follows:
@Configuration @EnableLoadTimeWeaving public class AppConfig { // application-specific @Bean definitions ... }The example above is equivalent to the following Spring XML configuration:
<beans>
<context:load-time-weaver/>
<!-- application-specific <bean> definitions -->
</beans>
LoadTimeWeaverAware
interfaceLoadTimeWeaverAware
interface
will then receive the LoadTimeWeaver
reference automatically; for example,
Spring's JPA bootstrap support.
LoadTimeWeaver
DefaultContextLoadTimeWeaver
.
To customize the weaver used, the @Configuration
class annotated with
@EnableLoadTimeWeaving
may also implement the LoadTimeWeavingConfigurer
interface and return a custom LoadTimeWeaver
instance through the
#getLoadTimeWeaver
method:
@Configuration @EnableLoadTimeWeaving public class AppConfig implements LoadTimeWeavingConfigurer { @Override public LoadTimeWeaver getLoadTimeWeaver() { MyLoadTimeWeaver ltw = new MyLoadTimeWeaver(); ltw.addClassTransformer(myClassFileTransformer); // ... return ltw; } }
The example above can be compared to the following Spring XML configuration:
<beans>
<context:load-time-weaver weaverClass="com.acme.MyLoadTimeWeaver"/>
</beans>
The code example differs from the XML example in that it actually instantiates the
MyLoadTimeWeaver
type, meaning that it can also configure the instance, e.g.
calling the #addClassTransformer
method. This demonstrates how the code-based
configuration approach is more flexible through direct programmatic access.
aspectjWeaving()
attribute, which will cause the AspectJ class transformer to
be registered through LoadTimeWeaver.addTransformer(java.lang.instrument.ClassFileTransformer)
. AspectJ weaving will be
activated by default if a "META-INF/aop.xml" resource is present on the classpath.
Example:
@Configuration @EnableLoadTimeWeaving(aspectjWeaving=ENABLED) public class AppConfig { }
The example above can be compared to the following Spring XML configuration:
<beans>
<context:load-time-weaver aspectj-weaving="on"/>
</beans>
The two examples are equivalent with one significant exception: in the XML case,
the functionality of <context:spring-configured>
is implicitly enabled when
aspectj-weaving
is "on". This does not occur when using
@EnableLoadTimeWeaving(aspectjWeaving=ENABLED)
. Instead you must explicitly add
@EnableSpringConfigured
(included in the spring-aspects
module)
LoadTimeWeaver
,
DefaultContextLoadTimeWeaver
,
ClassPreProcessorAgentAdapter
Modifier and Type | Optional Element and Description |
---|---|
EnableLoadTimeWeaving.AspectJWeaving |
aspectjWeaving
Whether AspectJ weaving should be enabled.
|
public abstract EnableLoadTimeWeaving.AspectJWeaving aspectjWeaving