Merge pull request #13 from IngProjDutzlerHeiligenbrunnerMeindl/dbReconnect

Db reconnect

src/java/com/wasteinformationserver/Main.kt

@@ -37,14 +37,8 @@ fun main() {
 
     //initial connect to db
     Log.message("initial login to db")
-    try {
+    val stor = Storage.getInstance();
-        val stor = Storage.getInstance();
+    JDBC.init(stor.dbUser, stor.dbPassword, stor.dbName, stor.dbhost, stor.dbPort)
-        JDBC.init(stor.dbUser, stor.dbPassword, stor.dbName, stor.dbhost, stor.dbPort)
-        //JDBC.init("ingproject", "Kb9Dxklumt76ieq6", "ingproject", "db.power4future.at", 3306)
-        //JDBC.init("users", "kOpaIJUjkgb9ur6S", "wasteinformation", "192.168.65.15", 3306);
-    } catch (e: IOException) {
-        Log.error("no connection to db")
-    }
 
 
     //startup web server
@@ -57,7 +51,6 @@ fun main() {
 
     if (JDBC.isConnected()) {
         val m = MqttService(Storage.getInstance().mqttServer, Storage.getInstance().mqttPort.toString())
-        //    val m = MqttService("mqtt.heili.eu", "1883")
         m.startupService()
     }else{
         Log.error("could't start mqtt service because of missing db connection!")

src/java/com/wasteinformationserver/db/JDBC.java

@@ -1,6 +1,8 @@
 package com.wasteinformationserver.db;
 
+import com.mysql.cj.exceptions.ConnectionIsClosedException;
 import com.wasteinformationserver.basicutils.Log;
+import com.wasteinformationserver.basicutils.Storage;
 
 import java.io.IOException;
 import java.sql.*;
@@ -9,6 +11,7 @@ import java.sql.*;
  * basic connection class to a Database
  *
  * @author Lukas Heiligenbrunner
+ * @author Emil Meindl
  */
 public class JDBC {
     private static Connection conn;
@@ -22,7 +25,7 @@ public class JDBC {
     private static String ipc;
     private static int portc;
 
-    private JDBC(String username, String password, String dbname, String ip, int port) throws IOException {
+    private JDBC(String username, String password, String dbname, String ip, int port) {
         logintodb(username, password, dbname, ip, port);
     }
 
@@ -66,11 +69,7 @@ public class JDBC {
      */
     public static JDBC getInstance() {
         if (!loggedin) {
-            try {
+            logintodb(usernamec, passwordc, dbnamec, ipc, portc);
-                logintodb(usernamec, passwordc, dbnamec, ipc, portc);
-            } catch (IOException e) {
-                Log.Log.error("no connetion to db - retrying in 5min");
-            }
         }
         return JDBC;
     }
@@ -85,7 +84,7 @@ public class JDBC {
      * @param port     Server port
      * @throws IOException thrown if no connection to db is possible.
      */
-    private static void logintodb(String username, String password, String dbname, String ip, int port) throws IOException {
+    private static boolean logintodb(String username, String password, String dbname, String ip, int port) {
         try {
             DriverManager.setLoginTimeout(1);
             conn = DriverManager.getConnection(
@@ -93,10 +92,32 @@ public class JDBC {
                     username,
                     password);
             loggedin = true;
+            Log.Log.message("Connected to database");
         } catch (SQLException e) {
-            throw new IOException("No connection to database");
+            // reconnect every 10 sec
-            // todo reconnect every 5mins or something
+            Log.Log.warning("Database-Connection not possible");
+            new Thread(new Runnable() {
+                @Override
+                public void run() {
+                    try {
+                        Thread.sleep(10 * 1000);
+                    } catch (InterruptedException interruptedException) {
+                        interruptedException.printStackTrace();
+                    }
+                    Log.Log.debug("Reading config");
+                    Storage st = Storage.Companion.getInstance();
+                    st.init();
+                    usernamec = st.getDbName();
+                    passwordc = st.getDbPassword();
+                    dbnamec = st.getDbName();
+                    ipc = st.getDbhost();
+                    portc = st.getDbPort();
+                    Log.Log.info("Retry connection");
+                    loggedin = logintodb(usernamec, passwordc, dbnamec, ipc, portc);
+                }
+            }).start();
         }
+        return loggedin;
     }
 
     public void disconnect(){
@@ -115,12 +136,19 @@ public class JDBC {
      */
     public ResultSet executeQuery(String sql) {
         try {
+            conn.isValid(5);
             PreparedStatement stmt = conn.prepareStatement(sql);
             return stmt.executeQuery();
+        } catch (SQLNonTransientConnectionException ee){
+            if (logintodb(usernamec, passwordc, dbnamec, ipc, portc)) {
+                return this.executeQuery(sql);
+            } else {
+                return null;
+            }
         } catch (SQLException e) {
-            e.printStackTrace();
+            return null;
         }
-        return null;
+
     }
 
     /**
@@ -131,9 +159,19 @@ public class JDBC {
      * @throws SQLException
      */
     public int executeUpdate(String sql) throws SQLException {
-        PreparedStatement stmt = conn.prepareStatement(sql);
+        try {
-
+            conn.isValid(5);
-        return stmt.executeUpdate();
+            PreparedStatement stmt = conn.prepareStatement(sql);
+            return stmt.executeUpdate();
+        } catch (SQLNonTransientConnectionException ee){
+            if (logintodb(usernamec, passwordc, dbnamec, ipc, portc)) {
+                return this.executeUpdate(sql);
+            } else {
+                throw new SQLException();
+            }
+        } catch (SQLException e){
+            throw new SQLException();
+        }
     }
 
     /**