Use Supplier variants of Assert methods

See gh-12630

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/AutoConfigurationImportSelector.java

@@ -129,8 +129,9 @@ public class AutoConfigurationImportSelector
 		AnnotationAttributes attributes = AnnotationAttributes
 				.fromMap(metadata.getAnnotationAttributes(name, true));
 		Assert.notNull(attributes,
-				"No auto-configuration attributes found. Is " + metadata.getClassName()
-						+ " annotated with " + ClassUtils.getShortName(name) + "?");
+				() -> "No auto-configuration attributes found. Is "
+						+ metadata.getClassName() + " annotated with "
+						+ ClassUtils.getShortName(name) + "?");
 		return attributes;
 	}
 

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/cache/CacheAutoConfiguration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -149,7 +149,7 @@ public class CacheAutoConfiguration {
 		@PostConstruct
 		public void checkHasCacheManager() {
 			Assert.notNull(this.cacheManager,
-					"No cache manager could "
+					() -> "No cache manager could "
 							+ "be auto-configured, check your configuration (caching "
 							+ "type is '" + this.cacheProperties.getType() + "')");
 		}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/cache/CacheProperties.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -107,7 +107,7 @@ public class CacheProperties {
 	 */
 	public Resource resolveConfigLocation(Resource config) {
 		if (config != null) {
-			Assert.isTrue(config.exists(), "Cache configuration does not exist '"
+			Assert.isTrue(config.exists(), () -> "Cache configuration does not exist '"
 					+ config.getDescription() + "'");
 			return config;
 		}

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

@@ -503,8 +503,8 @@ class OnBeanCondition extends SpringBootCondition implements ConfigurationCondit
 
 		@Override
 		protected void validate(BeanTypeDeductionException ex) {
-			Assert.isTrue(getTypes().size() == 1, annotationName() + " annotations must "
-					+ "specify only one type (got " + getTypes() + ")");
+			Assert.isTrue(getTypes().size() == 1, () -> annotationName()
+					+ " annotations must specify only one type (got " + getTypes() + ")");
 		}
 
 	}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/hazelcast/HazelcastProperties.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -52,7 +52,7 @@ public class HazelcastProperties {
 		if (this.config == null) {
 			return null;
 		}
-		Assert.isTrue(this.config.exists(), "Hazelcast configuration does not exist '"
+		Assert.isTrue(this.config.exists(), () -> "Hazelcast configuration does not exist '"
 				+ this.config.getDescription() + "'");
 		return this.config;
 	}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/jackson/JacksonAutoConfiguration.java

@@ -323,8 +323,8 @@ public class JacksonAutoConfiguration {
 				// that may be added by Jackson in the future)
 				Field field = ReflectionUtils.findField(PropertyNamingStrategy.class,
 						fieldName, PropertyNamingStrategy.class);
-				Assert.notNull(field, "Constant named '" + fieldName + "' not found on "
-						+ PropertyNamingStrategy.class.getName());
+				Assert.notNull(field, () -> "Constant named '" + fieldName
+						+ "' not found on " + PropertyNamingStrategy.class.getName());
 				try {
 					builder.propertyNamingStrategy(
 							(PropertyNamingStrategy) field.get(null));