closing db on exit

.gitignore

@@ -18,6 +18,8 @@ bin
 *.ear
 /target
 /src/main/java/samples
+/blockchain
+/state
 
 *.db
 *.xlsx

ethereumj-core/src/main/java/org/ethereum/db/Database.java

@@ -30,10 +30,12 @@ public class Database {
 	
 	private static Logger logger = LoggerFactory.getLogger(Database.class);
 	private DB db;
+    private String name;
 
 	
 	public Database(String name) {
     	// Initialize Database
+        this.name = name;
 		Options options = new Options();
 		options.createIfMissing(true);
 		try {
@@ -117,4 +119,13 @@ public class Database {
 		return this.db;
 	}
 
+    public void close(){
+        try {
+            logger.info("Release DB: {}", name);
+            db.close();
+        } catch (IOException e) {
+            logger.error("failed to find the db file on the close: {} ", name);
+        }
+    }
+
 }

ethereumj-core/src/main/java/org/ethereum/gui/ToolBar.java

@@ -1,5 +1,6 @@
 package org.ethereum.gui;
 
+import org.ethereum.db.Config;
 import org.ethereum.manager.MainData;
 import org.ethereum.util.Utils;
 import org.slf4j.Logger;
@@ -10,6 +11,8 @@ import javax.swing.*;
 import java.awt.*;
 import java.awt.event.ItemEvent;
 import java.awt.event.ItemListener;
+import java.awt.event.WindowAdapter;
+import java.awt.event.WindowEvent;
 
 /**
  * www.ethereumJ.com
@@ -68,6 +71,14 @@ public class ToolBar extends JFrame {
         setTitle("EthereumJ Studio");
         setDefaultCloseOperation(EXIT_ON_CLOSE);
 
+        addWindowListener(new WindowAdapter() {
+            @Override
+            public void windowClosing(WindowEvent e) {
+                Config.CHAIN_DB.close();
+                Config.STATE_DB.close();
+            }
+        });
+
         this.setContentPane(cp);
 
         java.net.URL imageURL_1 = ClassLoader.getSystemResource("buttons/feedly.png");