removed checked calls for JDBC and added connection check in JDBC class itself

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

@@ -1,4 +1,7 @@
 package com.wasteinformationserver.db;
+
+import com.wasteinformationserver.basicutils.Log;
+
 import java.io.IOException;
 import java.sql.Connection;
 import java.sql.PreparedStatement;
@@ -53,14 +56,15 @@ public class JDBC {
      * @return JDBC object of this
      * @throws IOException
      */
-    public static JDBC getInstance() throws IOException {
+    public static JDBC getInstance() {
-        if (loggedin) {
+        if (!loggedin) {
-            return JDBC;
+            try {
-        } else {
                 logintodb(usernamec, passwordc, dbnamec, ipc, portc);
-            return JDBC;
+            } catch (IOException e) {
+                Log.Log.error("no connetion to db - retrying in 5min");
             }
-
+        }
+        return JDBC;
     }
 
     private static void logintodb(String username, String password, String dbname, String ip, int port) throws IOException {
@@ -76,6 +80,7 @@ public class JDBC {
             loggedin = true;
         } catch (SQLException e) {
             throw new IOException("No connection to database");
+            // todo reconnect every 5mins or something
         }
 
     }
@@ -108,4 +113,8 @@ public class JDBC {
 
         return stmt.executeUpdate();
     }
+
+    public boolean isConnected() {
+        return loggedin;
+    }
 }

src/java/com/wasteinformationserver/mqtt/MqttService.kt

@@ -20,9 +20,9 @@ import java.util.*
  * @author Gregor Dutzler
  */
 class MqttService(serverurl: String, port: String) {
-    private var client: MqttClient? = null
+    private val serveruri: String = "tcp://$serverurl:$port"
-    private val serveruri: String
+    private var client: MqttClient = MqttClient(serveruri, "JavaSample42")
-    private var db: JDBC? = null
+    private var db: JDBC = JDBC.getInstance()
 
     /**
      * init mqtt service
@@ -32,8 +32,7 @@ class MqttService(serverurl: String, port: String) {
      * @param port      mqtt server port
      */
     init {
-        serveruri = "tcp://$serverurl:$port"
+        connectToDb()
-        connect()
     }
 
     /**
@@ -44,26 +43,27 @@ class MqttService(serverurl: String, port: String) {
             client = MqttClient(serveruri, "JavaSample42")
             val connOpts = MqttConnectOptions()
             connOpts.isCleanSession = true
-            client!!.connect(connOpts)
+            client.connect(connOpts)
-            client!!.setCallback(object : MqttCallback {
+            client.setCallback(object : MqttCallback {
                 override fun connectionLost(throwable: Throwable) {
                     error("connection lost")
-                    connect()
+                    connectToDb()
                 }
 
                 override fun messageArrived(s: String, mqttMessage: MqttMessage) {
                     val deviceid = String(mqttMessage.payload)
                     message("received Request from PCB")
-                    val res = db!!.executeQuery("SELECT * from devices WHERE DeviceID=$deviceid")
+                    val res = db.executeQuery("SELECT * from devices WHERE DeviceID=$deviceid")
                     try {
                         res.last()
                         if (res.row != 0) { //existing device
                             res.first()
-                            val devicecities = db!!.executeQuery("SELECT * from device_city WHERE DeviceID='$deviceid'")
+                            val devicecities = db.executeQuery("SELECT * from device_city WHERE DeviceID='$deviceid'")
                             devicecities.last()
                             if (devicecities.row == 0) { //not configured
                                 tramsmitMessage("$deviceid,-1")
-                            } else {
+                            }
+                            else {
                                 devicecities.first()
                                 devicecities.previous()
 
@@ -72,8 +72,9 @@ class MqttService(serverurl: String, port: String) {
                                     checkDatabase(cityid, deviceid.toInt())
                                 }
                             }
-                        } else { //new device
+                        }
-                            db!!.executeUpdate("INSERT INTO devices (DeviceID) VALUES ($deviceid)")
+                        else { //new device
+                            db.executeUpdate("INSERT INTO devices (DeviceID) VALUES ($deviceid)")
                             info("new device registered to server")
                             tramsmitMessage("$deviceid,-1")
                         }
@@ -84,7 +85,7 @@ class MqttService(serverurl: String, port: String) {
 
                 override fun deliveryComplete(iMqttDeliveryToken: IMqttDeliveryToken) {}
             })
-            client!!.subscribe("TopicIn")
+            client.subscribe("TopicIn")
         } catch (e: MqttException) {
             error("Connection to the Broker failed")
         }
@@ -92,24 +93,26 @@ class MqttService(serverurl: String, port: String) {
 
     private fun checkDatabase(citywastezoneid: Int, deviceid: Int) {
         var wastetype = -1
-        val set2 = db!!.executeQuery("SELECT * FROM cities WHERE `id`='$citywastezoneid'")
+        val set2 = db.executeQuery("SELECT * FROM cities WHERE `id`='$citywastezoneid'")
         try {
             set2.last()
             if (set2.row != 1) { //error
-            } else {
+            }
+            else {
                 val typ = set2.getString("wastetype")
                 wastetype = getIntTyp(typ)
             }
         } catch (e: SQLException) {
             e.printStackTrace()
         }
-        val result = db!!.executeQuery("SELECT pickupdates.pickupdate FROM pickupdates WHERE pickupdates.citywastezoneid=$citywastezoneid")
+        val result = db.executeQuery("SELECT pickupdates.pickupdate FROM pickupdates WHERE pickupdates.citywastezoneid=$citywastezoneid")
         try {
             result.last()
             if (result.row == 0) { //if not found in db --> send zero
                 debug("not found in db")
                 tramsmitMessage("$deviceid,$wastetype,0")
-            } else {
+            }
+            else {
                 debug(result.getString("pickupdate"))
                 result.first()
                 do {
@@ -138,41 +141,33 @@ class MqttService(serverurl: String, port: String) {
         val message = MqttMessage(temp.toByteArray())
         message.qos = 2
         try {
-            client!!.publish("TopicOut", message)
+            client.publish("TopicOut", message)
         } catch (e: MqttException) {
             e.printStackTrace()
         }
     }
 
     private fun getTyp(number: Int): String? {
-        if (number == 1) {
+        return when (number) {
-            return "Plastic"
+            1 -> "Plastic"
-        } else if (number == 2) {
+            2 -> "Metal"
-            return "Metal"
+            3 -> "Residual waste"
-        } else if (number == 3) {
+            4 -> "Biowaste"
-            return "Residual waste"
+            else -> null
-        } else if (number == 4) {
-            return "Biowaste"
         }
-        return null
     }
 
     private fun getIntTyp(temp: String): Int {
-        var number = 0
+        return when (temp) {
-        when (temp) {
+            "Plastic" -> 1
-            "Plastic" -> number = 1
+            "Metal" -> 2
-            "Metal" -> number = 2
+            "Residual waste" -> 3
-            "Residual waste" -> number = 3
+            "Biowaste" -> 4
-            "Biowaste" -> number = 4
+            else -> 0
         }
-        return number
     }
 
-    private fun connect() {
+    private fun connectToDb() {
-        try {
         db = JDBC.getInstance()
-        } catch (e: IOException) {
-            error("no connetion to db")
-        }
     }
 }

src/java/com/wasteinformationserver/website/datarequests/DataRequest.kt

@@ -6,7 +6,6 @@ import com.wasteinformationserver.basicutils.Log.Log.error
 import com.wasteinformationserver.basicutils.Log.Log.warning
 import com.wasteinformationserver.db.JDBC
 import com.wasteinformationserver.website.basicrequest.PostRequest
-import java.io.IOException
 import java.sql.ResultSet
 import java.sql.SQLException
 import java.sql.SQLIntegrityConstraintViolationException
@@ -18,12 +17,12 @@ class DataRequest : PostRequest() {
         val sb = StringBuilder()
         var set: ResultSet?
         var status = -1
-        val jdbc: JDBC = try {
+        val jdbc: JDBC = JDBC.getInstance()
-            JDBC.getInstance()
+        if (!jdbc.isConnected) {
-        } catch (e: IOException) {
             error("no connection to db")
             return "{\"query\" : \"nodbconn\"}"
         }
+
         when (params["action"]) {
             "newCity" -> {
                 sb.append("{")

src/java/com/wasteinformationserver/website/datarequests/DeviceRequest.kt

@@ -4,21 +4,20 @@ import com.wasteinformationserver.basicutils.Log.Log.debug
 import com.wasteinformationserver.basicutils.Log.Log.error
 import com.wasteinformationserver.db.JDBC
 import com.wasteinformationserver.website.basicrequest.PostRequest
-import java.io.IOException
 import java.sql.ResultSet
 import java.sql.SQLException
 import java.util.*
 
 class DeviceRequest : PostRequest() {
     override fun request(params: HashMap<String, String>): String {
-        var jdbc: JDBC? = null
+        val jdbc = JDBC.getInstance()
-        try {
+        if (!jdbc.isConnected) {
-            jdbc = JDBC.getInstance()
+            error("no connection to db")
-        } catch (e: IOException) {
+            return "{\"query\" : \"nodbconn\"}"
-            e.printStackTrace()
         }
+
         val sb = StringBuilder()
-        var deviceset: ResultSet
+        val deviceset: ResultSet
         when (params["action"]) {
             "getdevices" -> {
                 deviceset = jdbc!!.executeQuery("SELECT * FROM `devices")
@@ -135,7 +134,7 @@ class DeviceRequest : PostRequest() {
             }
             "deleteDevice" -> {
                 try {
-                    jdbc!!.executeUpdate("DELETE FROM devices WHERE `DeviceID`='" + params["id"] + "'")
+                    jdbc.executeUpdate("DELETE FROM devices WHERE `DeviceID`='" + params["id"] + "'")
                     jdbc.executeUpdate("DELETE FROM device_city WHERE `DeviceID`='" + params["id"] + "'")
                 } catch (e: SQLException) {
                     e.printStackTrace()
@@ -145,7 +144,7 @@ class DeviceRequest : PostRequest() {
             "addtodb" -> {
                 var cityid = -1
                 try {
-                    val device = jdbc!!.executeQuery("SELECT * FROM cities WHERE name='" + params["cityname"] + "' AND wastetype='" + params["wastetype"] + "' AND zone='" + params["zonename"] + "'")
+                    val device = jdbc.executeQuery("SELECT * FROM cities WHERE name='" + params["cityname"] + "' AND wastetype='" + params["wastetype"] + "' AND zone='" + params["zonename"] + "'")
                     device.first()
                     cityid = device.getInt("id")
                     jdbc.executeUpdate("INSERT INTO `device_city` (`DeviceID`, `CityID`) VALUES ('" + params["deviceid"] + "', '" + cityid + "');")
@@ -156,11 +155,11 @@ class DeviceRequest : PostRequest() {
             }
             "getheader" -> {
                 try {
-                    var numberset = jdbc!!.executeQuery("SELECT * FROM devices")
+                    var numberset = jdbc.executeQuery("SELECT * FROM devices")
                     numberset.last()
                     val devicenr = numberset.row
 
-                    numberset = jdbc!!.executeQuery("SELECT * FROM devices WHERE CityID=-1")
+                    numberset = jdbc.executeQuery("SELECT * FROM devices WHERE CityID=-1")
                     numberset.last()
                     val unconfigureddevices = numberset.row
 

src/java/com/wasteinformationserver/website/datarequests/NewDateRequest.java

@@ -4,7 +4,6 @@ import com.wasteinformationserver.basicutils.Log;
 import com.wasteinformationserver.db.JDBC;
 import com.wasteinformationserver.website.basicrequest.PostRequest;
 
-import java.io.IOException;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.util.HashMap;
@@ -13,14 +12,14 @@ public class NewDateRequest extends PostRequest {
     @Override
     public String request(HashMap<String, String> params) {
         StringBuilder sb = new StringBuilder();
-        JDBC jdbc;
         ResultSet set;
-        try {
+
-            jdbc = JDBC.getInstance();
+        JDBC jdbc = JDBC.getInstance();
-        } catch (IOException e) {
+        if (!jdbc.isConnected()) {
             Log.Log.error("no connection to db");
             return "{\"query\" : \"nodbconn\"}";
         }
+
         switch (params.get("action")) {
             case "getCitynames":
                 set = jdbc.executeQuery("select * from cities");