Detect Reactive web applications

This commit improves `@ConditionalOnWebApplication` to specify the
requested web application type. By default, any web application will
match but it can also match only if a recactive (or servlet) web
application is present.

Closes gh-8118

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2017 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.
@@ -25,10 +25,12 @@ import java.lang.annotation.Target;
 import org.springframework.context.annotation.Conditional;
 
 /**
- * {@link Conditional} that only matches when the application context is a web application
- * context.
+ * {@link Conditional} that matches when the application is a web application. By default,
+ * any web application will match but it can be narrowed using the {@link #type()}
+ * attribute.
  *
  * @author Dave Syer
+ * @author Stephane Nicoll
  */
 @Target({ ElementType.TYPE, ElementType.METHOD })
 @Retention(RetentionPolicy.RUNTIME)
@@ -36,4 +38,32 @@ import org.springframework.context.annotation.Conditional;
 @Conditional(OnWebApplicationCondition.class)
 public @interface ConditionalOnWebApplication {
 
+	/**
+	 * The required type of the web application.
+	 * @return the required web application type
+	 */
+	Type type() default Type.ANY;
+
+	/**
+	 * Available application types.
+	 */
+	enum Type {
+
+		/**
+		 * Any web application will match.
+		 */
+		ANY,
+
+		/**
+		 * Only servlet-based web application will match.
+		 */
+		SERVLET,
+
+		/**
+		 * Only reactive-based web application will match.
+		 */
+		REACTIVE
+
+	}
+
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2017 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.
@@ -16,6 +16,10 @@
 
 package org.springframework.boot.autoconfigure.condition;
 
+import java.util.Map;
+
+import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication.Type;
+import org.springframework.boot.context.embedded.ReactiveWebApplicationContext;
 import org.springframework.context.annotation.Condition;
 import org.springframework.context.annotation.ConditionContext;
 import org.springframework.core.Ordered;
@@ -59,6 +63,35 @@ class OnWebApplicationCondition extends SpringBootCondition {
 			AnnotatedTypeMetadata metadata, boolean required) {
 		ConditionMessage.Builder message = ConditionMessage.forCondition(
 				ConditionalOnWebApplication.class, required ? "(required)" : "");
+		Type type = deduceType(metadata);
+		if (Type.SERVLET == type) {
+			return isServletWebApplication(context);
+		}
+		else if (Type.REACTIVE == type) {
+			return isReactiveWebApplication(context);
+		}
+		else {
+			ConditionOutcome servletOutcome = isServletWebApplication(context);
+			if (servletOutcome.isMatch() && required) {
+				return new ConditionOutcome(servletOutcome.isMatch(),
+						message.because(servletOutcome.getMessage()));
+			}
+			ConditionOutcome reactiveOutcome = isReactiveWebApplication(context);
+			if (reactiveOutcome.isMatch() && required)  {
+				return new ConditionOutcome(reactiveOutcome.isMatch(),
+						message.because(reactiveOutcome.getMessage()));
+			}
+			boolean finalOutcome = (required ?
+					servletOutcome.isMatch() && reactiveOutcome.isMatch() :
+					servletOutcome.isMatch() || reactiveOutcome.isMatch());
+			return new ConditionOutcome(finalOutcome, message.because(
+					servletOutcome.getMessage()).append("and").append(
+							reactiveOutcome.getMessage()));
+		}
+	}
+
+	private ConditionOutcome isServletWebApplication(ConditionContext context) {
+		ConditionMessage.Builder message = ConditionMessage.forCondition("");
 		if (!ClassUtils.isPresent(WEB_CONTEXT_CLASS, context.getClassLoader())) {
 			return ConditionOutcome
 					.noMatch(message.didNotFind("web application classes").atAll());
@@ -76,7 +109,26 @@ class OnWebApplicationCondition extends SpringBootCondition {
 		if (context.getResourceLoader() instanceof WebApplicationContext) {
 			return ConditionOutcome.match(message.foundExactly("WebApplicationContext"));
 		}
-		return ConditionOutcome.noMatch(message.because("not a web application"));
+		return ConditionOutcome.noMatch(message.because("not a servlet web application"));
+	}
+
+	private ConditionOutcome isReactiveWebApplication(ConditionContext context) {
+		ConditionMessage.Builder message = ConditionMessage.forCondition("");
+		if (context.getResourceLoader() instanceof ReactiveWebApplicationContext) {
+			return ConditionOutcome.match(
+					message.foundExactly("ReactiveWebApplicationContext"));
+		}
+		return ConditionOutcome.noMatch(message.because(
+				"not a reactive web application"));
+	}
+
+	private Type deduceType(AnnotatedTypeMetadata metadata) {
+		Map<String, Object> attributes = metadata.getAnnotationAttributes(
+				ConditionalOnWebApplication.class.getName());
+		if (attributes != null) {
+			return (Type) attributes.get("type");
+		}
+		return Type.ANY;
 	}
 
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2017 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.
@@ -16,56 +16,76 @@
 
 package org.springframework.boot.autoconfigure.condition;
 
+import org.junit.After;
 import org.junit.Test;
 
+import org.springframework.boot.context.embedded.ReactiveWebApplicationContext;
+import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.mock.web.MockServletContext;
+import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.entry;
 
 /**
  * Tests for {@link ConditionalOnNotWebApplication}.
  *
- * @author Dave Syer
+ * @author Dave Syer$
+ * @author Stephane Nicoll
  */
 public class ConditionalOnNotWebApplicationTests {
 
-	private final AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
+	private ConfigurableApplicationContext context;
 
-	@Test
-	public void testWebApplication() {
-		this.context.register(BasicConfiguration.class);
-		this.context.refresh();
-		assertThat(this.context.containsBean("foo")).isTrue();
-		assertThat(this.context.getBean("foo")).isEqualTo("foo");
+	@After
+	public void closeContext() {
+		if (this.context != null) {
+			this.context.close();
+		}
 	}
 
 	@Test
-	public void testNotWebApplication() {
-		this.context.register(MissingConfiguration.class);
-		this.context.refresh();
-		assertThat(this.context.containsBean("foo")).isFalse();
+	public void testNotWebApplicationWithServletContext() {
+		AnnotationConfigWebApplicationContext ctx = new AnnotationConfigWebApplicationContext();
+		ctx.register(NotWebApplicationConfiguration.class);
+		ctx.setServletContext(new MockServletContext());
+		ctx.refresh();
+
+		this.context = ctx;
+		assertThat(this.context.getBeansOfType(String.class)).isEmpty();
 	}
 
-	@Configuration
-	@ConditionalOnWebApplication
-	protected static class MissingConfiguration {
+	@Test
+	public void testNotWebApplicationWithReactiveContext() {
+		ReactiveWebApplicationContext ctx = new ReactiveWebApplicationContext();
+		ctx.register(NotWebApplicationConfiguration.class);
+		ctx.refresh();
 
-		@Bean
-		public String bar() {
-			return "bar";
+		this.context = ctx;
+		assertThat(this.context.getBeansOfType(String.class)).isEmpty();
 	}
 
+	@Test
+	public void testNotWebApplication() {
+		AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext();
+		ctx.register(NotWebApplicationConfiguration.class);
+		ctx.refresh();
+
+		this.context = ctx;
+		assertThat(this.context.getBeansOfType(String.class)).containsExactly(
+				entry("none", "none"));
 	}
 
 	@Configuration
 	@ConditionalOnNotWebApplication
-	protected static class BasicConfiguration {
+	protected static class NotWebApplicationConfiguration {
 
 		@Bean
-		public String foo() {
-			return "foo";
+		public String none() {
+			return "none";
 		}
 
 	}

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2017 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.
@@ -16,59 +16,106 @@
 
 package org.springframework.boot.autoconfigure.condition;
 
+import org.junit.After;
 import org.junit.Test;
 
+import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication.Type;
+import org.springframework.boot.context.embedded.ReactiveWebApplicationContext;
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.mock.web.MockServletContext;
 import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.entry;
 
 /**
  * Tests for {@link ConditionalOnWebApplication}.
  *
  * @author Dave Syer
+ * @author Stephane Nicoll
  */
 public class ConditionalOnWebApplicationTests {
 
-	private final AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();
+	private ConfigurableApplicationContext context;
+
+	@After
+	public void closeContext() {
+		if (this.context != null) {
+			this.context.close();
+		}
+	}
 
 	@Test
-	public void testWebApplication() {
-		this.context.register(BasicConfiguration.class);
-		this.context.setServletContext(new MockServletContext());
-		this.context.refresh();
-		assertThat(this.context.containsBean("foo")).isTrue();
-		assertThat(this.context.getBean("foo")).isEqualTo("foo");
+	public void testWebApplicationWithServletContext() {
+		AnnotationConfigWebApplicationContext ctx = new AnnotationConfigWebApplicationContext();
+		ctx.register(AnyWebApplicationConfiguration.class,
+				ServletWebApplicationConfiguration.class,
+				ReactiveWebApplicationConfiguration.class);
+		ctx.setServletContext(new MockServletContext());
+		ctx.refresh();
+
+		this.context = ctx;
+		assertThat(this.context.getBeansOfType(String.class)).containsExactly(
+				entry("any", "any"), entry("servlet", "servlet"));
 	}
 
 	@Test
-	public void testNotWebApplication() {
-		this.context.register(MissingConfiguration.class);
-		this.context.setServletContext(new MockServletContext());
-		this.context.refresh();
-		assertThat(this.context.containsBean("foo")).isFalse();
+	public void testWebApplicationWithReactiveContext() {
+		ReactiveWebApplicationContext ctx = new ReactiveWebApplicationContext();
+		ctx.register(AnyWebApplicationConfiguration.class,
+				ServletWebApplicationConfiguration.class,
+				ReactiveWebApplicationConfiguration.class);
+		ctx.refresh();
+
+		this.context = ctx;
+		assertThat(this.context.getBeansOfType(String.class)).containsExactly(
+				entry("any", "any"), entry("reactive", "reactive"));
+	}
+
+	@Test
+	public void testNonWebApplication() {
+		AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext();
+		ctx.register(AnyWebApplicationConfiguration.class,
+				ServletWebApplicationConfiguration.class,
+				ReactiveWebApplicationConfiguration.class);
+		ctx.refresh();
+
+		this.context = ctx;
+		assertThat(this.context.getBeansOfType(String.class)).isEmpty();
 	}
 
 	@Configuration
-	@ConditionalOnNotWebApplication
-	protected static class MissingConfiguration {
+	@ConditionalOnWebApplication
+	protected static class AnyWebApplicationConfiguration {
 
 		@Bean
-		public String bar() {
-			return "bar";
+		public String any() {
+			return "any";
 		}
 
 	}
 
 	@Configuration
-	@ConditionalOnWebApplication
-	protected static class BasicConfiguration {
+	@ConditionalOnWebApplication(type = Type.SERVLET)
+	protected static class ServletWebApplicationConfiguration {
+
+		@Bean
+		public String servlet() {
+			return "servlet";
+		}
+
+	}
+
+	@Configuration
+	@ConditionalOnWebApplication(type = Type.REACTIVE)
+	protected static class ReactiveWebApplicationConfiguration {
 
 		@Bean
-		public String foo() {
-			return "foo";
+		public String reactive() {
+			return "reactive";
 		}
 
 	}

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/logging/AutoConfigurationReportLoggingInitializerTests.java

@@ -171,7 +171,8 @@ public class AutoConfigurationReportLoggingInitializerTests {
 		}
 		// Just basic sanity check, test is for visual inspection
 		String l = this.debugLog.get(0);
-		assertThat(l).contains("not a web application (OnWebApplicationCondition)");
+		assertThat(l).contains(
+				"not a servlet web application (OnWebApplicationCondition)");
 	}
 
 	@Test