Move DiskSpaceHealthIndicator path checks

By moving the exists and readable checks from
DiskSpaceHealthIndicatorProperties to DiskSpaceHealthIndicator they are
executed later. This gives the application the possibility to access the
configured path and to create it before the DiskSpaceHealthIndicator
actually needs it.

Author: Phoosha

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/system/DiskSpaceHealthContributorAutoConfiguration.java

@@ -16,6 +16,8 @@
 
 package org.springframework.boot.actuate.autoconfigure.system;
 
+import java.io.File;
+
 import org.springframework.boot.actuate.autoconfigure.health.ConditionalOnEnabledHealthIndicator;
 import org.springframework.boot.actuate.autoconfigure.health.HealthContributorAutoConfiguration;
 import org.springframework.boot.actuate.system.DiskSpaceHealthIndicator;
@@ -25,6 +27,7 @@
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.util.Assert;
 
 /**
  * {@link EnableAutoConfiguration Auto-configuration} for
@@ -43,7 +46,12 @@ public class DiskSpaceHealthContributorAutoConfiguration {
 	@Bean
 	@ConditionalOnMissingBean(name = "diskSpaceHealthIndicator")
 	public DiskSpaceHealthIndicator diskSpaceHealthIndicator(DiskSpaceHealthIndicatorProperties properties) {
-		return new DiskSpaceHealthIndicator(properties.getPath(), properties.getThreshold());
+		File path = properties.getPath();
+
+		Assert.isTrue(path.exists(), () -> "Path '" + path + "' does not exist");
+		Assert.isTrue(path.canRead(), () -> "Path '" + path + "' cannot be read");
+
+		return new DiskSpaceHealthIndicator(path, properties.getThreshold());
 	}
 
 }

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/system/DiskSpaceHealthIndicatorProperties.java

@@ -48,8 +48,6 @@ public File getPath() {
 	}
 
 	public void setPath(File path) {
-		Assert.isTrue(path.exists(), () -> "Path '" + path + "' does not exist");
-		Assert.isTrue(path.canRead(), () -> "Path '" + path + "' cannot be read");
 		this.path = path;
 	}