Fix bootstrap-hosts property detection with list

Previously, if `spring.couchbase.bootstrap-hosts` was specified in YAML
or with the `[Idx]` notation, the auto-configuration would not kick in.

This is due to a limitation of `@ConditionalOnProperty` on a property of
type Collection. This commit workarounds this limitation for now with a
dedicated condition.

Closes gh-7508

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/couchbase/CouchbaseAutoConfiguration.java

@@ -28,7 +28,6 @@ import org.springframework.boot.autoconfigure.condition.AnyNestedCondition;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
-import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Conditional;
@@ -133,7 +132,7 @@ public class CouchbaseAutoConfiguration {
 			super(ConfigurationPhase.REGISTER_BEAN);
 		}
 
-		@ConditionalOnProperty(prefix = "spring.couchbase", name = "bootstrapHosts")
+		@Conditional(OnBootstrapHostsCondition.class)
 		static class BootstrapHostsProperty {
 		}
 

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/couchbase/OnBootstrapHostsCondition.java

@@ -0,0 +1,93 @@
+/*
+ * 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.
+ * 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.couchbase;
+
+import java.util.AbstractMap;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.springframework.boot.autoconfigure.condition.ConditionMessage;
+import org.springframework.boot.autoconfigure.condition.ConditionOutcome;
+import org.springframework.boot.autoconfigure.condition.SpringBootCondition;
+import org.springframework.boot.bind.PropertySourcesPropertyValues;
+import org.springframework.boot.bind.RelaxedDataBinder;
+import org.springframework.boot.bind.RelaxedNames;
+import org.springframework.context.annotation.ConditionContext;
+import org.springframework.core.env.ConfigurableEnvironment;
+import org.springframework.core.type.AnnotatedTypeMetadata;
+import org.springframework.validation.DataBinder;
+
+/**
+ * Condition to determine if {@code spring.couchbase.bootstrap-hosts} is specified.
+ *
+ * @author Stephane Nicoll
+ */
+class OnBootstrapHostsCondition extends SpringBootCondition {
+
+	@Override
+	public ConditionOutcome getMatchOutcome(ConditionContext context,
+			AnnotatedTypeMetadata metadata) {
+		ConfigurableEnvironment environment = (ConfigurableEnvironment) context
+				.getEnvironment();
+		PropertyResolver resolver = new PropertyResolver(environment, "spring.couchbase");
+		Map.Entry<String, Object> entry = resolver.resolveProperty("bootstrap-hosts");
+		if (entry != null) {
+			return ConditionOutcome.match(
+					ConditionMessage.forCondition(OnBootstrapHostsCondition.class.getName())
+							.found("property").items("spring.couchbase.bootstrap-hosts"));
+		}
+		else {
+			return ConditionOutcome.noMatch(
+					ConditionMessage.forCondition(OnBootstrapHostsCondition.class.getName())
+							.didNotFind("property").items("spring.couchbase.bootstrap-hosts"));
+		}
+	}
+
+	private static class PropertyResolver {
+
+		private final String prefix;
+
+		private final Map<String, Object> content;
+
+		PropertyResolver(ConfigurableEnvironment environment, String prefix) {
+			this.prefix = prefix;
+			this.content = new HashMap<String, Object>();
+			DataBinder binder = new RelaxedDataBinder(this.content, this.prefix);
+			binder.bind(new PropertySourcesPropertyValues(
+					environment.getPropertySources()));
+		}
+
+		Map.Entry<String, Object> resolveProperty(String name) {
+			RelaxedNames prefixes = new RelaxedNames(this.prefix);
+			RelaxedNames keys = new RelaxedNames(name);
+			for (String prefix : prefixes) {
+				for (String relaxedKey : keys) {
+					String key = prefix + relaxedKey;
+					if (this.content.containsKey(relaxedKey)) {
+						return new AbstractMap.SimpleEntry<String, Object>(key,
+								this.content.get(relaxedKey));
+					}
+				}
+			}
+			return null;
+		}
+
+	}
+
+}
+
+

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/couchbase/OnBootstrapHostsConditionTests.java

@@ -0,0 +1,95 @@
+/*
+ * 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.
+ * 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.couchbase;
+
+import org.junit.After;
+import org.junit.Test;
+
+import org.springframework.boot.test.util.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.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link OnBootstrapHostsCondition}.
+ *
+ * @author Stephane Nicoll
+ */
+public class OnBootstrapHostsConditionTests {
+
+	private AnnotationConfigApplicationContext context;
+
+	@After
+	public void tearDown() {
+		if (this.context != null) {
+			this.context.close();
+		}
+	}
+
+	@Test
+	public void bootstrapHostsNotDefined() {
+		load(TestConfig.class);
+		assertThat(this.context.containsBean("foo")).isFalse();
+	}
+
+	@Test
+	public void bootstrapHostsDefinedAsCommaSeparated() {
+		load(TestConfig.class, "spring.couchbase.bootstrap-hosts=value1");
+		assertThat(this.context.containsBean("foo")).isTrue();
+	}
+
+	@Test
+	public void bootstrapHostsDefinedAsList() {
+		load(TestConfig.class, "spring.couchbase.bootstrap-hosts[0]=value1");
+		assertThat(this.context.containsBean("foo")).isTrue();
+	}
+
+	@Test
+	public void bootstrapHostsDefinedAsCommaSeparatedRelaxed() {
+		load(TestConfig.class, "spring.couchbase.bootstrapHosts=value1");
+		assertThat(this.context.containsBean("foo")).isTrue();
+	}
+
+	@Test
+	public void bootstrapHostsDefinedAsListRelaxed() {
+		load(TestConfig.class, "spring.couchbase.bootstrapHosts[0]=value1");
+		assertThat(this.context.containsBean("foo")).isTrue();
+	}
+
+
+	private void load(Class<?> config, String... environment) {
+		this.context = new AnnotationConfigApplicationContext();
+		EnvironmentTestUtils.addEnvironment(this.context, environment);
+		this.context.register(config);
+		this.context.refresh();
+	}
+
+	@Configuration
+	@Conditional(OnBootstrapHostsCondition.class)
+	protected static class TestConfig {
+
+		@Bean
+		public String foo() {
+			return "foo";
+		}
+
+	}
+
+}