Refine AbstractJarFile method visibility

Refine method visibility in an attempt to fix test issues on Java 11+.

See gh-22991

spring-boot-project/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/jar/AbstractJarFile.java

@@ -45,26 +45,26 @@ abstract class AbstractJarFile extends java.util.jar.JarFile {
 	 * @return the URL
 	 * @throws MalformedURLException if the URL is malformed
 	 */
-	protected abstract URL getUrl() throws MalformedURLException;
+	abstract URL getUrl() throws MalformedURLException;
 
 	/**
 	 * Return the {@link JarFileType} of this instance.
 	 * @return the jar file type
 	 */
-	protected abstract JarFileType getType();
+	abstract JarFileType getType();
 
 	/**
 	 * Return the security permission for this JAR.
 	 * @return the security permission.
 	 */
-	protected abstract Permission getPermission();
+	abstract Permission getPermission();
 
 	/**
 	 * Return an {@link InputStream} for the entire jar contents.
 	 * @return the contents input stream
 	 * @throws IOException on IO error
 	 */
-	protected abstract InputStream getInputStream() throws IOException;
+	abstract InputStream getInputStream() throws IOException;
 
 	/**
 	 * The type of a {@link JarFile}.

spring-boot-project/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/jar/JarFile.java

@@ -174,7 +174,7 @@ public class JarFile extends AbstractJarFile {
 	}
 
 	@Override
-	protected Permission getPermission() {
+	Permission getPermission() {
 		return new FilePermission(this.rootFile.getFile().getPath(), READ_ACTION);
 	}
 
@@ -225,7 +225,7 @@ public class JarFile extends AbstractJarFile {
 	}
 
 	@Override
-	protected InputStream getInputStream() throws IOException {
+	InputStream getInputStream() throws IOException {
 		return this.data.getInputStream();
 	}
 
@@ -389,7 +389,7 @@ public class JarFile extends AbstractJarFile {
 	}
 
 	@Override
-	protected JarFileType getType() {
+	JarFileType getType() {
 		return this.type;
 	}
 

spring-boot-project/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/jar/JarFileWrapper.java

@@ -43,17 +43,17 @@ class JarFileWrapper extends AbstractJarFile {
 	}
 
 	@Override
-	protected URL getUrl() throws MalformedURLException {
+	URL getUrl() throws MalformedURLException {
 		return this.parent.getUrl();
 	}
 
 	@Override
-	protected JarFileType getType() {
+	JarFileType getType() {
 		return this.parent.getType();
 	}
 
 	@Override
-	protected Permission getPermission() {
+	Permission getPermission() {
 		return this.parent.getPermission();
 	}
 
@@ -78,7 +78,7 @@ class JarFileWrapper extends AbstractJarFile {
 	}
 
 	@Override
-	protected InputStream getInputStream() throws IOException {
+	InputStream getInputStream() throws IOException {
 		return this.parent.getInputStream();
 	}