spring-projects#18 - Explicitly declare bean definitions target type for plugin registries.

We now use the API introduced in Spring Framework 4.3.3 to explicitly declare a ResolvableType for the BeanDefinition of the plugin registries. This allows to autowire registries as PluginRegisty<Foo, …> and PluginRegistry<Bar, …> without using explicit qualifiers.

Author: odrotbohm

core/src/main/java/org/springframework/plugin/core/config/PluginRegistriesBeanDefinitionRegistrar.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012 the original author or authors.
+ * Copyright 2012-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,13 +16,18 @@
 package org.springframework.plugin.core.config;
 
 import org.springframework.beans.factory.annotation.Qualifier;
-import org.springframework.beans.factory.support.AbstractBeanDefinition;
 import org.springframework.beans.factory.support.AutowireCandidateQualifier;
 import org.springframework.beans.factory.support.BeanDefinitionBuilder;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
+import org.springframework.beans.factory.support.RootBeanDefinition;
 import org.springframework.context.annotation.ImportBeanDefinitionRegistrar;
+import org.springframework.core.ResolvableType;
 import org.springframework.core.type.AnnotationMetadata;
+import org.springframework.plugin.core.OrderAwarePluginRegistry;
+import org.springframework.plugin.core.Plugin;
+import org.springframework.plugin.core.PluginRegistry;
 import org.springframework.plugin.core.support.PluginRegistryFactoryBean;
+import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
 /**
@@ -41,15 +46,17 @@ public class PluginRegistriesBeanDefinitionRegistrar implements ImportBeanDefini
 @Override
 public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
 
-Class<?>[] types = (Class<?>[]) importingClassMetadata.getAnnotationAttributes(
-EnablePluginRegistries.class.getName()).get("value");
+Class<?>[] types = (Class<?>[]) importingClassMetadata
+.getAnnotationAttributes(EnablePluginRegistries.class.getName()).get("value");
 
 for (Class<?> type : types) {
 
 BeanDefinitionBuilder builder = BeanDefinitionBuilder.rootBeanDefinition(PluginRegistryFactoryBean.class);
 builder.addPropertyValue("type", type);
 
-AbstractBeanDefinition beanDefinition = builder.getBeanDefinition();
+RootBeanDefinition beanDefinition = (RootBeanDefinition) builder.getBeanDefinition();
+beanDefinition.setTargetType(getTargetType(type));
+
 Qualifier annotation = type.getAnnotation(Qualifier.class);
 
 // If the plugin interface has a Qualifier annotation, propagate that to the bean definition of the registry
@@ -60,9 +67,25 @@ public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, B
 }
 
 // Default
-String beanName = annotation == null ? StringUtils.uncapitalize(type.getSimpleName() + "Registry") : annotation
-.value();
+String beanName = annotation == null ? StringUtils.uncapitalize(type.getSimpleName() + "Registry")
+: annotation.value();
 registry.registerBeanDefinition(beanName, builder.getBeanDefinition());
 }
 }
+
+/**
+ * Returns the target type of the {@link PluginRegistry} for the given plugin type.
+ * 
+ * @param pluginType must not be {@literal null}.
+ * @return
+ */
+private static ResolvableType getTargetType(Class<?> pluginClass) {
+
+Assert.notNull(pluginClass, "Plugin type must not be null!");
+
+ResolvableType delimiterType = ResolvableType.forClass(Plugin.class, pluginClass).getGeneric(0);
+ResolvableType pluginType = ResolvableType.forClass(pluginClass);
+
+return ResolvableType.forClassWithGenerics(OrderAwarePluginRegistry.class, pluginType, delimiterType);
+}
 }

core/src/test/java/org/springframework/plugin/core/config/EnablePluginRegistriesIntegrationTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012 the original author or authors.
+ * Copyright 2012-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -50,19 +50,15 @@ public SamplePluginImplementation pluginImpl() {
 }
 }
 
-@Autowired
-@Qualifier("samplePluginRegistry")
-PluginRegistry<SamplePlugin, String> registry;
+@Autowired PluginRegistry<SamplePlugin, String> registry;
 
 @Test
 public void registersPluginRegistries() {
 assertThat(registry, is(notNullValue()));
 }
 
 @Qualifier("myQualifier")
-interface AnotherPlugin extends Plugin<String> {
-
-}
+interface AnotherPlugin extends Plugin<String> {}
 
 static class AnotherSamplePluginImplementation implements AnotherPlugin {