OPENJPA-2768 delete xmlstore test db between runs.

This did lead to errors when running the tests multiple times.

openjpa-xmlstore/src/test/java/org/apache/openjpa/xmlstore/simple/TestPersistence.java

@@ -18,6 +18,11 @@
  */
 package org.apache.openjpa.xmlstore.simple;
 
+import java.io.File;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
 import javax.persistence.EntityManager;
 import javax.persistence.EntityTransaction;
 
@@ -30,6 +35,19 @@ import org.apache.openjpa.persistence.test.AbstractPersistenceTestCase;
  */
 public class TestPersistence extends AbstractPersistenceTestCase {
 
+    @Override
+    protected void setUp() throws Exception {
+        super.setUp();
+
+        // delete previous DB
+        Path dbDir = Paths.get("target/openjpa-xmlstore-db");
+        if (dbDir.toFile().exists()) {
+            Files.walk(dbDir)
+                    .map(Path::toFile)
+                    .forEach(File::delete);
+        }
+    }
+
     public void testCreateEntityManager() {
         OpenJPAEntityManagerFactorySPI emf = createNamedEMF("xmlstore-simple");
         try {

pom.xml

@@ -42,7 +42,7 @@
         <java.class.version>1.8</java.class.version>
         <java.testclass.version>1.8</java.testclass.version>
 
-	<doclint>none</doclint>
+        <doclint>none</doclint>
 
         <openjpa.version>${project.version}</openjpa.version>
         <openjpa.Log>DefaultLevel=INFO</openjpa.Log>