Be defensive about JarFileArchive creation

It doesn't make any difference with the old versions of Spring Boot
that we depend on here, but if we ever upgrade (or if a newer version
is on the classpath at runtime) the URL of a JarFileArchive is
incorrectly computed without this change.

Author: Dave Syer

launcher/src/main/java/org/springframework/boot/loader/thin/ArchiveUtils.java

@@ -23,7 +23,6 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
-import java.util.jar.JarFile;
 import java.util.jar.Manifest;
 
 import org.eclipse.aether.artifact.DefaultArtifact;
@@ -32,6 +31,7 @@
 import org.springframework.boot.loader.archive.Archive;
 import org.springframework.boot.loader.archive.ExplodedArchive;
 import org.springframework.boot.loader.archive.JarFileArchive;
+import org.springframework.boot.loader.jar.JarFile;
 import org.springframework.boot.loader.tools.MainClassFinder;
 import org.springframework.core.io.UrlResource;
 
@@ -52,7 +52,7 @@ public static Archive getArchive(String path) {
 			return new ExplodedArchive(file);
 		}
 		try {
-			return new JarFileArchive(file);
+			return new JarFileArchive(new JarFile(file));
 		}
 		catch (IOException e) {
 			throw new IllegalStateException("Cannot create JAR archive: " + file, e);