Fix bugs & vulns reported by Sonar

Plan/src/main/java/com/djrapitops/plan/system/database/databases/sql/SQLiteDB.java

@@ -57,19 +57,21 @@ public class SQLiteDB extends SQLDB {
         }
 
         String dbFilePath = new File(PlanPlugin.getInstance().getDataFolder(), dbName + ".db").getAbsolutePath();
-        Connection connection;
 
-        try {
+        Connection connection = getConnectionFor(dbFilePath);
-            connection = DriverManager.getConnection("jdbc:sqlite:" + dbFilePath + "?journal_mode=WAL");
-        } catch (SQLException ignored) {
-            connection = DriverManager.getConnection("jdbc:sqlite:" + dbFilePath);
-            Log.info("SQLite WAL mode not supported on this server version, using default. This may or may not affect performance.");
-        }
         connection.setAutoCommit(false);
-
         return connection;
     }
 
+    private Connection getConnectionFor(String dbFilePath) throws SQLException {
+        try {
+            return DriverManager.getConnection("jdbc:sqlite:" + dbFilePath + "?journal_mode=WAL");
+        } catch (SQLException ignored) {
+            Log.info("SQLite WAL mode not supported on this server version, using default. This may or may not affect performance.");
+            return DriverManager.getConnection("jdbc:sqlite:" + dbFilePath);
+        }
+    }
+
     private void startConnectionPingTask() {
         stopConnectionPingTask();
         try {
@@ -84,6 +86,7 @@ public class SQLiteDB extends SQLDB {
                             statement.execute("/* ping */ SELECT 1");
                         }
                     } catch (SQLException e) {
+                        Log.debug("Something went wrong during Ping task.");
                         try {
                             connection = getNewConnection(dbName);
                         } catch (SQLException e1) {

Plan/src/main/java/com/djrapitops/plan/system/processing/importing/importers/Importer.java

@@ -73,6 +73,7 @@ public abstract class Importer {
             service.awaitTermination(Long.MAX_VALUE, TimeUnit.NANOSECONDS);
         } catch (InterruptedException e) {
             Log.toLog(this.getClass().getName(), e);
+            Thread.currentThread().interrupt();
         }
 
         Benchmark.stop(benchmarkName);

Plan/src/main/java/com/djrapitops/plan/system/processing/processors/player/RegisterProcessor.java

@@ -11,6 +11,7 @@ import com.djrapitops.plan.system.cache.SessionCache;
 import com.djrapitops.plan.system.database.databases.Database;
 import com.djrapitops.plan.system.processing.Processor;
 import com.djrapitops.plan.system.processing.processors.ObjectProcessor;
+import com.djrapitops.plan.utilities.NullCheck;
 import com.djrapitops.plugin.api.utility.log.Log;
 
 import java.util.UUID;
@@ -41,6 +42,7 @@ public class RegisterProcessor extends PlayerProcessor {
     public void process() {
         UUID uuid = getUUID();
         Database db = Database.getActive();
+        NullCheck.check(uuid, new IllegalStateException("UUID was null"));
         try {
             if (!db.check().isPlayerRegistered(uuid)) {
                 db.save().registerNewUser(uuid, registered, name);

Plan/src/main/java/com/djrapitops/plan/utilities/analysis/AnalysisUtils.java

@@ -123,7 +123,7 @@ public class AnalysisUtils {
     }
 
     public static double getAveragePerDay(long after, long before, long total) {
-        return total / getNumberOfDaysBetween(after, before);
+        return (double) total / getNumberOfDaysBetween(after, before);
     }
 
     public static long getNumberOfDaysBetween(long start, long end) {
@@ -134,7 +134,7 @@ public class AnalysisUtils {
             test += day;
             value++;
         }
-        return value;
+        return value == 0 ? 1 : value;
     }
 
     public static void addMissingWorlds(WorldTimes worldTimes) {
@@ -196,7 +196,7 @@ public class AnalysisUtils {
                     stickM++;
                 }
             }
-            probability *= (stickM / similarM.size());
+            probability *= ((double) stickM / similarM.size());
         }
 
         if (!similarW.isEmpty()) {
@@ -207,7 +207,7 @@ public class AnalysisUtils {
                 }
             }
 
-            probability *= (stickW / similarW.size());
+            probability *= ((double) stickW / similarW.size());
         }
 
         return probability;

Plan/src/main/java/com/djrapitops/plan/utilities/file/export/HtmlExport.java

@@ -167,7 +167,6 @@ public class HtmlExport extends SpecificExport {
         copyFromJar(resources, true);
     }
 
-
     private void copyFromJar(String[] resources, boolean overwrite) {
         for (String resource : resources) {
             try {
@@ -185,8 +184,9 @@ public class HtmlExport extends SpecificExport {
         File to = new File(outputFolder, outputFile);
         to.getParentFile().mkdirs();
         if (to.exists()) {
-            to.delete();
+            if (!to.delete() || !to.createNewFile()) {
-            to.createNewFile();
+                return;
+            }
         }
         export(to, lines);
     }

Plan/src/test/java/com/djrapitops/plan/system/database/databases/SQLiteTest.java

@@ -855,6 +855,16 @@ public class SQLiteTest {
         assertTrue(db.getUserInfoTable().isRegistered(playerUUID));
     }
 
+    @Test
+    public void testRegister() throws DBException {
+        assertFalse(db.check().isPlayerRegistered(playerUUID));
+        assertFalse(db.check().isPlayerRegisteredOnThisServer(playerUUID));
+        db.save().registerNewUser(playerUUID, 1000L, "name");
+        db.save().registerNewUserOnThisServer(playerUUID, 500L);
+        assertTrue(db.check().isPlayerRegistered(playerUUID));
+        assertTrue(db.check().isPlayerRegisteredOnThisServer(playerUUID));
+    }
+
     @Test
     public void testWorldTableGetWorldNamesNoException() throws SQLException {
         Set<String> worldNames = db.getWorldTable().getWorldNames();