Added DB initialization logic and upgrade needed detection

Former-commit-id: 7a8b4d8157529a10c242ea995c0d2a4939b4d142

src/se/koc/hal/HalContext.java

@@ -1,40 +1,68 @@
 package se.koc.hal;
 
 import zutil.db.DBConnection;
+import zutil.db.handler.PropertiesSQLHandler;
+import zutil.io.file.FileUtil;
+import zutil.log.LogUtil;
 
+import java.io.File;
 import java.io.FileReader;
+import java.io.IOException;
+import java.sql.SQLException;
 import java.util.Properties;
+import java.util.logging.Logger;
 
 public class HalContext {
+    private static final Logger logger = LogUtil.getLogger();
+
     // Constants
     private static final String CONF_FILE = "hal.conf";
+    private static final String DB_FILE = "hal.db";
+    private static final String DEFAULT_DB_FILE = "hal-default.db";
 
     // Variables
     private static DBConnection db;
 
+    private static Properties defaultFileConf;
 	private static Properties fileConf;
-	private static Properties defaultConf;
+	private static Properties dbConf;
 
 
 	static {
-		defaultConf = new Properties();
-		defaultConf.setProperty("http_port", ""+8080);
-		defaultConf.setProperty("sync_port", ""+6666);
-
-        HalContext.initialize();
+		defaultFileConf = new Properties();
+		defaultFileConf.setProperty("http_port", ""+8080);
+		defaultFileConf.setProperty("sync_port", ""+6666);
 	}
 	
 	
 	public static void initialize(){
         try {
             // Read conf
-            fileConf = new Properties(defaultConf);
+            fileConf = new Properties(defaultFileConf);
             FileReader in = new FileReader(CONF_FILE);
             fileConf.load(in);
             in.close();
 
             // Init DB
-            db = new DBConnection(DBConnection.DBMS.SQLite, "hal.db");
+            if(FileUtil.find(DB_FILE) == null){
+                logger.info("Creating new DB...");
+                resetDB();
+            }
+            db = new DBConnection(DBConnection.DBMS.SQLite, DB_FILE);
+
+            // Read DB conf
+            dbConf = new Properties();
+            db.exec("SELECT * FROM conf", new PropertiesSQLHandler(dbConf));
+
+            // Upgrade DB needed?
+            DBConnection defaultDB = new DBConnection(DBConnection.DBMS.SQLite, DEFAULT_DB_FILE);
+            Properties defaultDBConf =
+                    db.exec("SELECT * FROM conf", new PropertiesSQLHandler(new Properties()));
+            if(defaultDBConf.getProperty("db_version").compareTo(dbConf.getProperty("db_version")) > 0) {
+                logger.info("Upgrading DB (from: v"+dbConf.getProperty("db_version") +", to: v"+defaultDBConf.getProperty("db_version"));
+                upgradeDB();
+            }
+            defaultDB.close();
         } catch (Exception e){
             throw new RuntimeException(e);
         }
@@ -54,4 +82,34 @@ public class HalContext {
     public static DBConnection getDB(){
         return db;
     }
+
+
+    /*************************************************************************/
+
+    private static void resetDB() throws IOException {
+        FileUtil.copy(DEFAULT_DB_FILE, DB_FILE);
+    }
+
+    // Todo:
+    private static void upgradeDB() throws SQLException {
+        /*
+        - beginTransaction
+        - run a table creation with if not exists (we are doing an upgrade, so the table might not exists yet, it will fail alter and drop)
+        - put in a list the existing columns List<String> columns = DBUtils.GetColumns(db, TableName);
+        - backup table (ALTER table " + TableName + " RENAME TO 'temp_"                    + TableName)
+        - create new table (the newest table creation schema)
+        - get the intersection with the new columns, this time columns taken from the upgraded table (columns.retainAll(DBUtils.GetColumns(db, TableName));)
+        - restore data (String cols = StringUtils.join(columns, ",");
+                    db.execSQL(String.format(
+                            "INSERT INTO %s (%s) SELECT %s from temp_%s",
+                            TableName, cols, cols, TableName));
+        )
+        - remove backup table (DROP table 'temp_" + TableName)
+        - setTransactionSuccessful
+         */
+        logger.severe("DB Upgrade not implemented yes!");
+        //db.exec("BeginTransaction");
+
+        //db.exec("EndTransaction");
+    }
 }

src/se/koc/hal/PowerChallenge.java

@@ -23,19 +23,22 @@ import java.util.logging.Level;
 public class PowerChallenge {
 
 	
-    private static HalDaemon[] daemons = new HalDaemon[]{
-            new DataAggregatorDaemon(),
-            new DataSynchronizationDaemon(),
-            new DataSynchronizationClient()
-    };
+    private static HalDaemon[] daemons;
 
     public static void main(String[] args) throws Exception {
+        // init logging
+        LogUtil.setGlobalLevel(Level.ALL);
+        LogUtil.setGlobalFormatter(new CompactLogFormatter());
 
-    	// init logging
-    	LogUtil.setGlobalLevel(Level.ALL);
-    	LogUtil.setGlobalFormatter(new CompactLogFormatter());
+        // init DB and other configurations
+        HalContext.initialize();
 
         // init daemons
+        daemons = new HalDaemon[]{
+                new DataAggregatorDaemon(),
+                new DataSynchronizationDaemon(),
+                new DataSynchronizationClient()
+        };
         Timer daemonTimer = new Timer();
         for(HalDaemon daemon : daemons){
             daemon.initiate(daemonTimer);