Support for composed "any" condition

Add `AnyNestedCondition` which can be used to create a logical 'or' of
other conditions contained on nested classes. For example:

	static class OnJndiOrProperty extends AnyNestedCondition {

		@ConditionalOnJndi()
		static class OnJndi {
		}

		@ConditionalOnProperty("something")
		static class OnProperty {
		}

	}

Fixes gh-1490

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/condition/AnyNestedCondition.java

+/*
+ * Copyright 2012-2014 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.boot.autoconfigure.condition;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+
+import org.springframework.beans.BeanUtils;
+import org.springframework.context.annotation.Condition;
+import org.springframework.context.annotation.ConditionContext;
+import org.springframework.context.annotation.Conditional;
+import org.springframework.context.annotation.ConfigurationCondition;
+import org.springframework.core.type.AnnotatedTypeMetadata;
+import org.springframework.core.type.AnnotationMetadata;
+import org.springframework.core.type.classreading.MetadataReaderFactory;
+import org.springframework.core.type.classreading.SimpleMetadataReaderFactory;
+import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
+import org.springframework.util.StringUtils;
+
+/**
+ * {@link Condition} that will match when any nested class condition matches. Can be used
+ * to create composite conditions, for example:
+ *
+ * <pre class="code">
+ * static class OnJndiOrProperty extends AnyNestedCondition {
+ *
+ *    &#064ConditionalOnJndi()
+ *    static class OnJndi {
+ *    }
+
+ *    &#064ConditionalOnProperty("something")
+ *    static class OnProperty {
+ *    }
+ *
+ * }
+ * </pre>
+ *
+ * @author Phillip Webb
+ * @since 1.2.0
+ */
+public abstract class AnyNestedCondition extends SpringBootCondition implements
+		ConfigurationCondition {
+
+	private final ConfigurationPhase configurationPhase;
+
+	public AnyNestedCondition(ConfigurationPhase configurationPhase) {
+		Assert.notNull(configurationPhase, "ConfigurationPhase must not be null");
+		this.configurationPhase = configurationPhase;
+	}
+
+	@Override
+	public ConfigurationPhase getConfigurationPhase() {
+		return this.configurationPhase;
+	}
+
+	@Override
+	public ConditionOutcome getMatchOutcome(ConditionContext context,
+			AnnotatedTypeMetadata metadata) {
+		MemberConditions memberConditions = new MemberConditions(context, getClass()
+				.getName());
+		List<ConditionOutcome> outcomes = memberConditions.getMatchOutcomes();
+		List<ConditionOutcome> match = new ArrayList<ConditionOutcome>();
+		List<ConditionOutcome> nonMatch = new ArrayList<ConditionOutcome>();
+		for (ConditionOutcome outcome : outcomes) {
+			if (outcome.isMatch()) {
+				match.add(outcome);
+			}
+			else {
+				nonMatch.add(outcome);
+			}
+		}
+		return new ConditionOutcome(match.size() > 0, "any match resulted in " + match
+				+ " matches and " + nonMatch + " non matches");
+	}
+
+	private static class MemberConditions {
+
+		private final ConditionContext context;
+
+		private final MetadataReaderFactory readerFactory;
+
+		private final Map<AnnotationMetadata, List<Condition>> memberConditions;
+
+		public MemberConditions(ConditionContext context, String className) {
+			this.context = context;
+			this.readerFactory = new SimpleMetadataReaderFactory(
+					context.getResourceLoader());
+			String[] members = getMetadata(className).getMemberClassNames();
+			this.memberConditions = getMemberConditions(members);
+		}
+
+		private Map<AnnotationMetadata, List<Condition>> getMemberConditions(
+				String[] members) {
+			MultiValueMap<AnnotationMetadata, Condition> memberConditions = new LinkedMultiValueMap<AnnotationMetadata, Condition>();
+			for (String member : members) {
+				AnnotationMetadata metadata = getMetadata(member);
+				for (String[] conditionClasses : getConditionClasses(metadata)) {
+					for (String conditionClass : conditionClasses) {
+						Condition condition = getCondition(conditionClass);
+						memberConditions.add(metadata, condition);
+					}
+				}
+			}
+			return Collections.unmodifiableMap(memberConditions);
+		}
+
+		private AnnotationMetadata getMetadata(String className) {
+			try {
+				return this.readerFactory.getMetadataReader(className)
+						.getAnnotationMetadata();
+			}
+			catch (IOException ex) {
+				throw new IllegalStateException(ex);
+			}
+		}
+
+		@SuppressWarnings("unchecked")
+		private List<String[]> getConditionClasses(AnnotatedTypeMetadata metadata) {
+			MultiValueMap<String, Object> attributes = metadata
+					.getAllAnnotationAttributes(Conditional.class.getName(), true);
+			Object values = (attributes != null ? attributes.get("value") : null);
+			return (List<String[]>) (values != null ? values : Collections.emptyList());
+		}
+
+		private Condition getCondition(String conditionClassName) {
+			Class<?> conditionClass = ClassUtils.resolveClassName(conditionClassName,
+					this.context.getClassLoader());
+			return (Condition) BeanUtils.instantiateClass(conditionClass);
+		}
+
+		public List<ConditionOutcome> getMatchOutcomes() {
+			List<ConditionOutcome> outcomes = new ArrayList<ConditionOutcome>();
+			for (Map.Entry<AnnotationMetadata, List<Condition>> entry : this.memberConditions
+					.entrySet()) {
+				AnnotationMetadata metadata = entry.getKey();
+				for (Condition condition : entry.getValue()) {
+					outcomes.add(getConditionOutcome(metadata, condition));
+				}
+			}
+			return Collections.unmodifiableList(outcomes);
+		}
+
+		private ConditionOutcome getConditionOutcome(AnnotationMetadata metadata,
+				Condition condition) {
+			String messagePrefix = "member condition on " + metadata.getClassName();
+			if (condition instanceof SpringBootCondition) {
+				ConditionOutcome outcome = ((SpringBootCondition) condition)
+						.getMatchOutcome(this.context, metadata);
+				String message = outcome.getMessage();
+				return new ConditionOutcome(outcome.isMatch(), messagePrefix
+						+ (StringUtils.hasLength(message) ? " : " + message : ""));
+			}
+			boolean matches = condition.matches(this.context, metadata);
+			return new ConditionOutcome(matches, messagePrefix);
+		}
+
+	}
+
+}

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/condition/ConditionOutcome.java

@@ -93,4 +93,8 @@ public class ConditionOutcome {
 		return super.equals(obj);
 	}
 
+	@Override
+	public String toString() {
+		return (this.message == null ? "" : this.message);
+	}
 }

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/condition/AnyNestedConditionTests.java

+/*
+ * Copyright 2012-2014 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.boot.autoconfigure.condition;
+
+import org.junit.Test;
+import org.springframework.boot.test.EnvironmentTestUtils;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Conditional;
+import org.springframework.context.annotation.Configuration;
+
+import static org.hamcrest.Matchers.equalTo;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Tests for {@link AnyNestedCondition}.
+ *
+ * @author Phillip Webb
+ */
+public class AnyNestedConditionTests {
+
+	@Test
+	public void neither() throws Exception {
+		AnnotationConfigApplicationContext context = load(OnPropertyAorBCondition.class);
+		assertThat(context.containsBean("myBean"), equalTo(false));
+		context.close();
+	}
+
+	@Test
+	public void propertyA() throws Exception {
+		AnnotationConfigApplicationContext context = load(Config.class, "a:a");
+		assertThat(context.containsBean("myBean"), equalTo(true));
+		context.close();
+	}
+
+	@Test
+	public void propertyB() throws Exception {
+		AnnotationConfigApplicationContext context = load(Config.class, "b:b");
+		assertThat(context.containsBean("myBean"), equalTo(true));
+		context.close();
+	}
+
+	@Test
+	public void both() throws Exception {
+		AnnotationConfigApplicationContext context = load(Config.class, "a:a", "b:b");
+		assertThat(context.containsBean("myBean"), equalTo(true));
+		context.close();
+	}
+
+	private AnnotationConfigApplicationContext load(Class<?> config, String... env) {
+		AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
+		EnvironmentTestUtils.addEnvironment(context, env);
+		context.register(config);
+		context.refresh();
+		return context;
+	}
+
+	@Configuration
+	@Conditional(OnPropertyAorBCondition.class)
+	public static class Config {
+
+		@Bean
+		public String myBean() {
+			return "myBean";
+		}
+
+	}
+
+	static class OnPropertyAorBCondition extends AnyNestedCondition {
+
+		public OnPropertyAorBCondition() {
+			super(ConfigurationPhase.PARSE_CONFIGURATION);
+		}
+
+		@ConditionalOnProperty("a")
+		static class HasPropertyA {
+
+		}
+
+		@ConditionalOnProperty("b")
+		static class HasPropertyB {
+
+		}
+
+	}
+
+}