Polish

spring-boot-project/spring-boot-starters/pom.xml

 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<parent>
@@ -145,6 +146,9 @@
 							<ignoredResourcePatterns>
 								<ignoredResourcePattern>changelog.txt</ignoredResourcePattern>
 							</ignoredResourcePatterns>
+							<ignoredClassPatterns>
+								<ignoredClassPattern>module-info</ignoredClassPattern>
+							</ignoredClassPatterns>
 						</configuration>
 					</execution>
 				</executions>

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/SpringApplication.java

@@ -164,12 +164,9 @@ public class SpringApplication {
 	 * The class name of application context that will be used by default for web
 	 * environments.
 	 */
-	public static final String DEFAULT_WEB_CONTEXT_CLASS = "org.springframework.boot."
+	public static final String DEFAULT_SERVLET_WEB_CONTEXT_CLASS = "org.springframework.boot."
 			+ "web.servlet.context.AnnotationConfigServletWebServerApplicationContext";
 
-	private static final String[] WEB_ENVIRONMENT_CLASSES = { "javax.servlet.Servlet",
-			"org.springframework.web.context.ConfigurableWebApplicationContext" };
-
 	/**
 	 * The class name of application context that will be used by default for reactive web
 	 * environments.
@@ -177,14 +174,6 @@ public class SpringApplication {
 	public static final String DEFAULT_REACTIVE_WEB_CONTEXT_CLASS = "org.springframework."
 			+ "boot.web.reactive.context.AnnotationConfigReactiveWebServerApplicationContext";
 
-	private static final String REACTIVE_WEB_ENVIRONMENT_CLASS = "org.springframework."
-			+ "web.reactive.DispatcherHandler";
-
-	private static final String MVC_WEB_ENVIRONMENT_CLASS = "org.springframework."
-			+ "web.servlet.DispatcherServlet";
-
-	private static final String JERSEY_WEB_ENVIRONMENT_CLASS = "org.glassfish.jersey.server.ResourceConfig";
-
 	/**
 	 * Default banner location.
 	 */
@@ -266,27 +255,13 @@ public class SpringApplication {
 		this.resourceLoader = resourceLoader;
 		Assert.notNull(primarySources, "PrimarySources must not be null");
 		this.primarySources = new LinkedHashSet<>(Arrays.asList(primarySources));
-		this.webApplicationType = deduceWebApplicationType();
+		this.webApplicationType = WebApplicationType.deduceFromClasspath();
 		setInitializers((Collection) getSpringFactoriesInstances(
 				ApplicationContextInitializer.class));
 		setListeners((Collection) getSpringFactoriesInstances(ApplicationListener.class));
 		this.mainApplicationClass = deduceMainApplicationClass();
 	}
 
-	private WebApplicationType deduceWebApplicationType() {
-		if (ClassUtils.isPresent(REACTIVE_WEB_ENVIRONMENT_CLASS, null)
-				&& !ClassUtils.isPresent(MVC_WEB_ENVIRONMENT_CLASS, null)
-				&& !ClassUtils.isPresent(JERSEY_WEB_ENVIRONMENT_CLASS, null)) {
-			return WebApplicationType.REACTIVE;
-		}
-		for (String className : WEB_ENVIRONMENT_CLASSES) {
-			if (!ClassUtils.isPresent(className, null)) {
-				return WebApplicationType.NONE;
-			}
-		}
-		return WebApplicationType.SERVLET;
-	}
-
 	private Class<?> deduceMainApplicationClass() {
 		try {
 			StackTraceElement[] stackTrace = new RuntimeException().getStackTrace();
@@ -596,7 +571,7 @@ public class SpringApplication {
 			try {
 				switch (this.webApplicationType) {
 				case SERVLET:
-					contextClass = Class.forName(DEFAULT_WEB_CONTEXT_CLASS);
+					contextClass = Class.forName(DEFAULT_SERVLET_WEB_CONTEXT_CLASS);
 					break;
 				case REACTIVE:
 					contextClass = Class.forName(DEFAULT_REACTIVE_WEB_CONTEXT_CLASS);
@@ -1173,38 +1148,16 @@ public class SpringApplication {
 
 	/**
 	 * Sets the type of Spring {@link ApplicationContext} that will be created. If not
-	 * specified defaults to {@link #DEFAULT_WEB_CONTEXT_CLASS} for web based applications
-	 * or {@link AnnotationConfigApplicationContext} for non web based applications.
+	 * specified defaults to {@link #DEFAULT_SERVLET_WEB_CONTEXT_CLASS} for web based
+	 * applications or {@link AnnotationConfigApplicationContext} for non web based
+	 * applications.
 	 * @param applicationContextClass the context class to set
 	 */
 	public void setApplicationContextClass(
 			Class<? extends ConfigurableApplicationContext> applicationContextClass) {
 		this.applicationContextClass = applicationContextClass;
-		this.webApplicationType = deduceWebApplicationType(applicationContextClass);
-	}
-
-	private WebApplicationType deduceWebApplicationType(
-			Class<?> applicationContextClass) {
-		if (safeIsAssignableFrom("org.springframework.web.context.WebApplicationContext",
-				applicationContextClass)) {
-			return WebApplicationType.SERVLET;
-		}
-		if (safeIsAssignableFrom(
-				"org.springframework.boot.web.reactive.context.ReactiveWebApplicationContext",
-				applicationContextClass)) {
-			return WebApplicationType.REACTIVE;
-		}
-		return WebApplicationType.NONE;
-	}
-
-	private boolean safeIsAssignableFrom(String target, Class<?> type) {
-		try {
-			Class<?> targetClass = ClassUtils.forName(target, getClassLoader());
-			return targetClass.isAssignableFrom(type);
-		}
-		catch (Throwable ex) {
-			return false;
-		}
+		this.webApplicationType = WebApplicationType
+				.deduceFromApplicationContext(applicationContextClass);
 	}
 
 	/**

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/WebApplicationType.java

@@ -16,6 +16,8 @@
 
 package org.springframework.boot;
 
+import org.springframework.util.ClassUtils;
+
 /**
  * An enumeration of possible types of web application.
  *
@@ -41,6 +43,55 @@ public enum WebApplicationType {
 	 * The application should run as a reactive web application and should start an
 	 * embedded reactive web server.
 	 */
-	REACTIVE
+	REACTIVE;
+
+	private static final String[] SERVLET_INDICATOR_CLASSES = { "javax.servlet.Servlet",
+			"org.springframework.web.context.ConfigurableWebApplicationContext" };
+
+	private static final String WEBMVC_INDICATOR_CLASS = "org.springframework."
+			+ "web.servlet.DispatcherServlet";
+
+	private static final String WEBFLUX_INDICATOR_CLASS = "org."
+			+ "springframework.web.reactive.DispatcherHandler";
+
+	private static final String JERSEY_INDICATOR_CLASS = "org.glassfish.jersey.server.ResourceConfig";
+
+	private static final String SERVLET_APPLICATION_CONTEXT_CLASS = "org.springframework.web.context.WebApplicationContext";
+
+	private static final String REACTIVE_APPLICATION_CONTEXT_CLASS = "org.springframework.boot.web.reactive.context.ReactiveWebApplicationContext";
+
+	static WebApplicationType deduceFromClasspath() {
+		if (ClassUtils.isPresent(WEBFLUX_INDICATOR_CLASS, null)
+				&& !ClassUtils.isPresent(WEBMVC_INDICATOR_CLASS, null)
+				&& !ClassUtils.isPresent(JERSEY_INDICATOR_CLASS, null)) {
+			return WebApplicationType.REACTIVE;
+		}
+		for (String className : SERVLET_INDICATOR_CLASSES) {
+			if (!ClassUtils.isPresent(className, null)) {
+				return WebApplicationType.NONE;
+			}
+		}
+		return WebApplicationType.SERVLET;
+	}
+
+	static WebApplicationType deduceFromApplicationContext(
+			Class<?> applicationContextClass) {
+		if (isAssignable(SERVLET_APPLICATION_CONTEXT_CLASS, applicationContextClass)) {
+			return WebApplicationType.SERVLET;
+		}
+		if (isAssignable(REACTIVE_APPLICATION_CONTEXT_CLASS, applicationContextClass)) {
+			return WebApplicationType.REACTIVE;
+		}
+		return WebApplicationType.NONE;
+	}
+
+	private static boolean isAssignable(String target, Class<?> type) {
+		try {
+			return ClassUtils.resolveClassName(target, null).isAssignableFrom(type);
+		}
+		catch (Throwable ex) {
+			return false;
+		}
+	}
 
 }