Improve error message when no resources exist at a script location

See gh-25620

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

 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 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.
@@ -161,7 +161,7 @@ class DataSourceInitializer {
 				}
 				else if (validate) {
 					throw new InvalidConfigurationPropertyValueException(propertyName, resource,
-							"The specified resource does not exist.");
+							"Resource '" + location + "' does not exist.");
 				}
 			}
 		}

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/jdbc/DataSourceInitializerInvokerTests.java

 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2021 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.
@@ -221,8 +221,10 @@ class DataSourceInitializerInvokerTests {
 				"spring.datasource.schema:classpath:does/not/exist.sql").run((context) -> {
 					assertThat(context).hasFailed();
 					assertThat(context.getStartupFailure()).isInstanceOf(BeanCreationException.class);
-					assertThat(context.getStartupFailure()).hasMessageContaining("does/not/exist.sql");
+					assertThat(context.getStartupFailure()).hasMessageContaining("[does/not/exist.sql]");
 					assertThat(context.getStartupFailure()).hasMessageContaining("spring.datasource.schema");
+					assertThat(context.getStartupFailure())
+							.hasMessageContaining("Resource 'classpath:does/not/exist.sql' does not exist.");
 				});
 	}
 
@@ -233,8 +235,10 @@ class DataSourceInitializerInvokerTests {
 				"spring.datasource.data:classpath:does/not/exist.sql").run((context) -> {
 					assertThat(context).hasFailed();
 					assertThat(context.getStartupFailure()).isInstanceOf(BeanCreationException.class);
-					assertThat(context.getStartupFailure()).hasMessageContaining("does/not/exist.sql");
+					assertThat(context.getStartupFailure()).hasMessageContaining("[does/not/exist.sql]");
 					assertThat(context.getStartupFailure()).hasMessageContaining("spring.datasource.data");
+					assertThat(context.getStartupFailure())
+							.hasMessageContaining("Resource 'classpath:does/not/exist.sql' does not exist.");
 				});
 	}