Optimize OnEnabledResourceChainCondition

Optimize OnEnabledResourceChainCondition by removing the DataBinder.
Properties are now read directly from the Environment.

See gh-7573

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/OnEnabledResourceChainCondition.java

 /*
- * 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.
@@ -19,11 +19,11 @@ package org.springframework.boot.autoconfigure.web;
 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.RelaxedPropertyResolver;
 import org.springframework.context.annotation.Condition;
 import org.springframework.context.annotation.ConditionContext;
 import org.springframework.core.env.ConfigurableEnvironment;
+import org.springframework.core.env.PropertyResolver;
 import org.springframework.core.type.AnnotatedTypeMetadata;
 import org.springframework.util.ClassUtils;
 
@@ -32,6 +32,7 @@ import org.springframework.util.ClassUtils;
  * enabled.
  *
  * @author Stephane Nicoll
+ * @author Phillip Webb
  * @see ConditionalOnEnabledResourceChain
  */
 class OnEnabledResourceChainCondition extends SpringBootCondition {
@@ -43,10 +44,10 @@ class OnEnabledResourceChainCondition extends SpringBootCondition {
 			AnnotatedTypeMetadata metadata) {
 		ConfigurableEnvironment environment = (ConfigurableEnvironment) context
 				.getEnvironment();
-		ResourceProperties properties = new ResourceProperties();
-		RelaxedDataBinder binder = new RelaxedDataBinder(properties, "spring.resources");
-		binder.bind(new PropertySourcesPropertyValues(environment.getPropertySources()));
-		Boolean match = properties.getChain().getEnabled();
+		boolean fixed = getEnabledProperty(environment, "strategy.fixed.", false);
+		boolean content = getEnabledProperty(environment, "strategy.content.", false);
+		Boolean chain = getEnabledProperty(environment, "", null);
+		Boolean match = ResourceProperties.Chain.getEnabled(fixed, content, chain);
 		ConditionMessage.Builder message = ConditionMessage
 				.forCondition(ConditionalOnEnabledResourceChain.class);
 		if (match == null) {
@@ -63,4 +64,11 @@ class OnEnabledResourceChainCondition extends SpringBootCondition {
 		return ConditionOutcome.noMatch(message.because("disabled"));
 	}
 
+	private Boolean getEnabledProperty(ConfigurableEnvironment environment, String key,
+			Boolean defaultValue) {
+		PropertyResolver resolver = new RelaxedPropertyResolver(environment,
+				"spring.resources.chain." + key);
+		return resolver.getProperty("enabled", Boolean.class, defaultValue);
+	}
+
 }

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/ResourceProperties.java

 /*
- * 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.
@@ -186,9 +186,8 @@ public class ResourceProperties implements ResourceLoaderAware {
 		 * settings are present.
 		 */
 		public Boolean getEnabled() {
-			Boolean strategyEnabled = getStrategy().getFixed().isEnabled()
-					|| getStrategy().getContent().isEnabled();
-			return (strategyEnabled ? Boolean.TRUE : this.enabled);
+			return getEnabled(getStrategy().getFixed().isEnabled(),
+					getStrategy().getContent().isEnabled(), this.enabled);
 		}
 
 		public void setEnabled(boolean enabled) {
@@ -223,6 +222,11 @@ public class ResourceProperties implements ResourceLoaderAware {
 			this.gzipped = gzipped;
 		}
 
+		static Boolean getEnabled(boolean fixedEnabled, boolean contentEnabled,
+				Boolean chainEnabled) {
+			return (fixedEnabled || contentEnabled ? Boolean.TRUE : chainEnabled);
+		}
+
 	}
 
 	/**