Added support for creating PluginRegistry instances via JavaConfig.

Introduced @EnablePluginRegistries to list the Plugin interfaces the container shall expose PluginRegistry instances for.

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

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2012 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.plugin.core.config;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Inherited;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.context.annotation.Import;
+import org.springframework.plugin.core.Plugin;
+import org.springframework.plugin.core.PluginRegistry;
+
+/**
+ * Enables exposure of {@link PluginRegistry} instances for the configured {@link Plugin} types
+ * 
+ * @see #value()
+ * @author Oliver Gierke
+ */
+@Target(ElementType.TYPE)
+@Retention(RetentionPolicy.RUNTIME)
+@Inherited
+@Documented
+@Import(PluginRegistriesBeanDefinitionRegistrar.class)
+public @interface EnablePluginRegistries {
+
+	/**
+	 * The {@link Plugin} types to register {@link PluginRegistry} instances for. The registries will be named after the
+	 * uncapitalized plugin type extended with {@code Registry}. So for a plugin interface {@code SamplePlugin} the
+	 * exposed bean name will be {@code samplePluginRegistry}. This can be used on the client side to make sure you get
+	 * the right {@link PluginRegistry} injected by using the {@link Qualifier} annotation and referring to that bean
+	 * name. If the auto-generated bean name collides with one already in your application you can use the
+	 * {@link Qualifier} annotation right at the plugin interface to define a custom name.
+	 * 
+	 * @return
+	 */
+	Class<? extends Plugin<?>>[] value();
+}

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

@@ -0,0 +1,68 @@
+/*
+ * Copyright 2012 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+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.context.annotation.ImportBeanDefinitionRegistrar;
+import org.springframework.core.type.AnnotationMetadata;
+import org.springframework.plugin.core.support.PluginRegistryFactoryBean;
+import org.springframework.util.StringUtils;
+
+/**
+ * {@link ImportBeanDefinitionRegistrar} to register {@link PluginRegistryFactoryBean} instances for type listed in
+ * {@link EnablePluginRegistries}. Picks up {@link Qualifier} annotations used on the plugin interface and forwards them
+ * to the bean definition for the factory.
+ * 
+ * @author Oliver Gierke
+ */
+public class PluginRegistriesBeanDefinitionRegistrar implements ImportBeanDefinitionRegistrar {
+
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.context.annotation.ImportBeanDefinitionRegistrar#registerBeanDefinitions(org.springframework.core.type.AnnotationMetadata, org.springframework.beans.factory.support.BeanDefinitionRegistry)
+	 */
+	@Override
+	public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
+
+		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();
+			Qualifier annotation = type.getAnnotation(Qualifier.class);
+
+			// If the plugin interface has a Qualifier annotation, propagate that to the bean definition of the registry
+			if (annotation != null) {
+				AutowireCandidateQualifier qualifierMetadata = new AutowireCandidateQualifier(Qualifier.class);
+				qualifierMetadata.setAttribute(AutowireCandidateQualifier.VALUE_KEY, annotation.value());
+				beanDefinition.addQualifier(qualifierMetadata);
+			}
+
+			// Default
+			String beanName = annotation == null ? StringUtils.uncapitalize(type.getSimpleName() + "Registry") : annotation
+					.value();
+			registry.registerBeanDefinition(beanName, builder.getBeanDefinition());
+		}
+	}
+}

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

@@ -0,0 +1,73 @@
+/*
+ * Copyright 2012 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.plugin.core.config;
+
+import static org.hamcrest.CoreMatchers.*;
+import static org.junit.Assert.*;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.plugin.core.Plugin;
+import org.springframework.plugin.core.PluginRegistry;
+import org.springframework.plugin.core.SamplePlugin;
+import org.springframework.plugin.core.SamplePluginImplementation;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+
+/**
+ * Integration tests for {@link EnablePluginRegistries}.
+ * 
+ * @author Oliver Gierke
+ */
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration
+public class EnablePluginRegistriesIntegrationTest {
+
+	@Configuration
+	@EnablePluginRegistries({ SamplePlugin.class, AnotherPlugin.class })
+	static class Config {
+
+		@Bean
+		public SamplePluginImplementation pluginImpl() {
+			return new SamplePluginImplementation();
+		}
+	}
+
+	@Autowired
+	@Qualifier("samplePluginRegistry")
+	PluginRegistry<SamplePlugin, String> registry;
+
+	@Test
+	public void registersPluginRegistries() {
+		assertThat(registry, is(notNullValue()));
+	}
+
+	interface AnotherPlugin extends Plugin<String> {
+
+	}
+
+	static class AnotherSamplePluginImplementation implements AnotherPlugin {
+
+		@Override
+		public boolean supports(String delimiter) {
+			return true;
+		}
+	}
+}