org.wicketstuff.springreference
Class SpringReference<T>

java.lang.Object
  org.wicketstuff.springreference.AbstractSpringReference<T>
      org.wicketstuff.springreference.SpringReference<T>

Type Parameters:

T - type of the wrapped spring bean

All Implemented Interfaces:

Serializable, Cloneable, IClusterable

public class SpringReference<T>
extends AbstractSpringReference<T>
implements IClusterable

This class together with SpringReferenceSupporter is an alternative to wicket-spring's @SpringBean and SpringComponentInjector to integrate spring with wicket in a web application.

Inspired by the concept of Reference classes and by the implementation of @SpringBean this class was made to overcome the shortcomings of dynamic proxying classes (need for no-private no-arg constructor, final methods not working in some cases, method annotations lost). If you used @SpringBean and ever saw mysterious stack traces like:

 
 Caused by: java.lang.IllegalArgumentException: Protected method: fooMethod()V
        at net.sf.cglib.proxy.MethodProxy.invoke(MethodProxy.java:196)
        at org.apache.wicket.proxy.LazyInitProxyFactory$CGLibInterceptor.intercept(LazyInitProxyFactory.java:319)
 
 

 
 Caused by: java.lang.IllegalArgumentException: No visible constructors in class FooClass
        at net.sf.cglib.proxy.Enhancer.filterConstructors(Enhancer.java:531)
        at net.sf.cglib.proxy.Enhancer.generateClass(Enhancer.java:448)
        at net.sf.cglib.core.DefaultGeneratorStrategy.generate(DefaultGeneratorStrategy.java:25)
        at net.sf.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:216)
        at net.sf.cglib.proxy.Enhancer.createHelper(Enhancer.java:377)
        at net.sf.cglib.proxy.Enhancer.create(Enhancer.java:285)
 
 

Because this class does not need an IComponentInstantiationListener, does not use dynamic proxies and looks up spring beans lazily, it should be slightly faster. It also supports serializing as @SpringBean does.

Instances of this class use the SpringReferenceSupporter for bean lookup, so it must be registered in your wicket WebApplication init() method ( SpringReferenceSupporter.register(this);). Otherwise you will get NullPointerException when calling AbstractSpringReference.get(). See SpringReferenceSupporter for more information.

Declaration (you can declare it in your wicket components, models or your custom classes as well):

 
 private final SpringReference<AuthenticationManager> authenticationManagerRef = SpringReference.of(AuthenticationManager.class, "authenticationManager");
 private final SpringReference<AbstractRememberMeServices> rememberMeServicesRef = SpringReference.of(AbstractRememberMeServices.class);
 
 

 
 authenticationManagerRef.get().authenticate(token);
 AbstractRememberMeServices rememberMeServices = rememberMeServicesRef.get();
 
 

Author:

akiraly

See Also:

Serialized Form

SpringReference

public SpringReference(Class<T> clazz,
                       String name)

Constructor.

Parameters:

clazz - class of the wrapped spring bean, not null

name - beanName of the wrapped spring bean, can be null

of

public static <T> SpringReference<T> of(Class<T> clazz)

Creator method for easy usage. Use this if you only want to specify the type of the spring bean.

Type Parameters:

T - type of the wrapped spring bean

Parameters:

clazz - class of the wrapped spring bean, not null

Returns:

new SpringReference instance wrapping the spring bean

of

public static <T> SpringReference<T> of(Class<T> clazz,
                                        String name)

Creator method for easy usage. Use this if need to specify a spring bean by name too.

Type Parameters:

T - type of the wrapped spring bean

Parameters:

clazz - class of the wrapped spring bean, not null

name - name of the wrapped spring bean, can be null

Returns:

new SpringReference instance wrapping the spring bean

getSupporter

protected SpringReferenceSupporter getSupporter()

Specified by:

getSupporter in class AbstractSpringReference<T>

Returns:

object used to find the wrapped spring bean, not null

clone

public SpringReference<T> clone()

Overrides:

clone in class AbstractSpringReference<T>