Improve null-safety of module/spring-boot-devtools

See gh-47263

module/spring-boot-devtools/src/main/java/org/springframework/boot/devtools/classpath/PatternClassPathRestartStrategy.java

@@ -16,6 +16,8 @@
 
 package org.springframework.boot.devtools.classpath;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.boot.devtools.filewatch.ChangedFile;
 import org.springframework.util.AntPathMatcher;
 import org.springframework.util.StringUtils;
@@ -37,7 +39,7 @@ public class PatternClassPathRestartStrategy implements ClassPathRestartStrategy
 		this.excludePatterns = excludePatterns;
 	}
 
-	public PatternClassPathRestartStrategy(String excludePatterns) {
+	public PatternClassPathRestartStrategy(@Nullable String excludePatterns) {
 		this(StringUtils.commaDelimitedListToStringArray(excludePatterns));
 	}
 

module/spring-boot-devtools/src/main/java/org/springframework/boot/devtools/restart/classloader/ClassLoaderFile.java

@@ -47,7 +47,7 @@ public class ClassLoaderFile implements Serializable {
 	 * @param kind the kind of file
 	 * @param contents the file contents
 	 */
-	public ClassLoaderFile(Kind kind, byte[] contents) {
+	public ClassLoaderFile(Kind kind, byte @Nullable [] contents) {
 		this(kind, System.currentTimeMillis(), contents);
 	}
 

module/spring-boot-devtools/src/main/java/org/springframework/boot/devtools/restart/classloader/ClassLoaderFileRepository.java

@@ -41,6 +41,6 @@ public interface ClassLoaderFileRepository {
 	 * @param name the name of the file
 	 * @return a {@link ClassLoaderFile} or {@code null}
 	 */
-	@Nullable ClassLoaderFile getFile(String name);
+	@Nullable ClassLoaderFile getFile(@Nullable String name);
 
 }

module/spring-boot-devtools/src/main/java/org/springframework/boot/devtools/restart/classloader/ClassLoaderFiles.java

@@ -143,7 +143,7 @@ public class ClassLoaderFiles implements ClassLoaderFileRepository, Serializable
 	}
 
 	@Override
-	public @Nullable ClassLoaderFile getFile(String name) {
+	public @Nullable ClassLoaderFile getFile(@Nullable String name) {
 		return this.filesByName.get(name);
 	}