From a800aa0ecc5afd5e8813e79aea7ca1cddd48cce6 Mon Sep 17 00:00:00 2001
From: Oliver Gierke <info@olivergierke.de>
Date: Tue, 30 Aug 2016 11:53:32 +0200
Subject: [PATCH] #18 - Explicitly declare bean definitions target type for
 plugin registries.
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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.
---
 ...uginRegistriesBeanDefinitionRegistrar.java | 37 +++++++++++++++----
 ...EnablePluginRegistriesIntegrationTest.java | 10 ++---
 2 files changed, 33 insertions(+), 14 deletions(-)

diff --git a/core/src/main/java/org/springframework/plugin/core/config/PluginRegistriesBeanDefinitionRegistrar.java b/core/src/main/java/org/springframework/plugin/core/config/PluginRegistriesBeanDefinitionRegistrar.java
index 419f698..20256bf 100644
--- a/core/src/main/java/org/springframework/plugin/core/config/PluginRegistriesBeanDefinitionRegistrar.java
+++ b/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 class PluginRegistriesBeanDefinitionRegistrar implements ImportBeanDefini
 			}
 
 			// 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);
+	}
 }
diff --git a/core/src/test/java/org/springframework/plugin/core/config/EnablePluginRegistriesIntegrationTest.java b/core/src/test/java/org/springframework/plugin/core/config/EnablePluginRegistriesIntegrationTest.java
index 63f69b3..8160b55 100644
--- a/core/src/test/java/org/springframework/plugin/core/config/EnablePluginRegistriesIntegrationTest.java
+++ b/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.
@@ -50,9 +50,7 @@ public class EnablePluginRegistriesIntegrationTest {
 		}
 	}
 
-	@Autowired
-	@Qualifier("samplePluginRegistry")
-	PluginRegistry<SamplePlugin, String> registry;
+	@Autowired PluginRegistry<SamplePlugin, String> registry;
 
 	@Test
 	public void registersPluginRegistries() {
@@ -60,9 +58,7 @@ public class EnablePluginRegistriesIntegrationTest {
 	}
 
 	@Qualifier("myQualifier")
-	interface AnotherPlugin extends Plugin<String> {
-
-	}
+	interface AnotherPlugin extends Plugin<String> {}
 
 	static class AnotherSamplePluginImplementation implements AnotherPlugin {