Add more debug logging to DevTools

Add debug logging for the included and excluded URL patterns and
matching URLs.

Fixes gh-7478
Closes gh-7544

spring-boot-devtools/src/main/java/org/springframework/boot/devtools/restart/ChangeableUrls.java

@@ -30,6 +30,9 @@ import java.util.jar.Attributes;
 import java.util.jar.JarFile;
 import java.util.jar.Manifest;
 
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
 import org.springframework.boot.devtools.settings.DevToolsSettings;
 import org.springframework.util.StringUtils;
 
@@ -41,6 +44,8 @@ import org.springframework.util.StringUtils;
  */
 final class ChangeableUrls implements Iterable<URL> {
 
+	private static final Log logger = LogFactory.getLog(ChangeableUrls.class);
+
 	private final List<URL> urls;
 
 	private ChangeableUrls(URL... urls) {
@@ -52,6 +57,9 @@ final class ChangeableUrls implements Iterable<URL> {
 				reloadableUrls.add(url);
 			}
 		}
+		if (logger.isDebugEnabled()) {
+			logger.debug("Matching URLs for reloading : " + reloadableUrls);
+		}
 		this.urls = Collections.unmodifiableList(reloadableUrls);
 	}
 

spring-boot-devtools/src/main/java/org/springframework/boot/devtools/settings/DevToolsSettings.java

@@ -24,6 +24,9 @@ import java.util.List;
 import java.util.Map;
 import java.util.regex.Pattern;
 
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
 import org.springframework.core.io.UrlResource;
 import org.springframework.core.io.support.PropertiesLoaderUtils;
 
@@ -40,6 +43,8 @@ public class DevToolsSettings {
 	 */
 	public static final String SETTINGS_RESOURCE_LOCATION = "META-INF/spring-devtools.properties";
 
+	private static final Log logger = LogFactory.getLog(DevToolsSettings.class);
+
 	private static DevToolsSettings settings;
 
 	private final List<Pattern> restartIncludePatterns = new ArrayList<Pattern>();
@@ -105,6 +110,12 @@ public class DevToolsSettings {
 				settings.add(PropertiesLoaderUtils
 						.loadProperties(new UrlResource(urls.nextElement())));
 			}
+			if (logger.isDebugEnabled()) {
+				logger.debug("Included patterns for restart : "
+						+ settings.restartIncludePatterns);
+				logger.debug("Excluded patterns for restart : "
+						+ settings.restartExcludePatterns);
+			}
 			return settings;
 		}
 		catch (Exception ex) {