#58 -- validate git project directory

src/main/java/ru/ulstu/extractor/gitrepository/GitRepositoryService.java

@@ -192,6 +192,7 @@ public class GitRepositoryService {
     private void cloneOrUpdateRepo(String repositoryUrl, String branchName) throws GitAPIException, IOException {
         Git git;
         org.eclipse.jgit.lib.Repository localRepo;
+        validateOrClearRepositoryDirectory(getProjectDirectoryFile(repositoryUrl));
         if (projectDirExists(getProjectDirectoryFile(repositoryUrl))) {
             localRepo = new FileRepository(getProjectGitDirectory(repositoryUrl));
             git = new Git(localRepo);
@@ -210,6 +211,26 @@ public class GitRepositoryService {
         git.close();
     }
 
+    private void validateOrClearRepositoryDirectory(File projectDirectory) {
+        if (projectDirectory.exists()) {
+            try {
+                Git.open(projectDirectory).status().call();
+            } catch (Exception e) {
+                deleteDirectory(projectDirectory);
+            }
+        }
+    }
+
+    private boolean deleteDirectory(File directoryToBeDeleted) {
+        File[] allContents = directoryToBeDeleted.listFiles();
+        if (allContents != null) {
+            for (File file : allContents) {
+                deleteDirectory(file);
+            }
+        }
+        return directoryToBeDeleted.delete();
+    }
+
     private void cloneOrUpdateRepo(String url) throws GitAPIException, IOException {
         cloneOrUpdateRepo(url, null);
     }