Aron hat hier die Vorlage von Edward übernommen. Er hat Code für die Kommunikation mit der Datenbank an den gewünschten Stellen eingefügt.

.idea/.name

+Schockwelle

app/arontestprojekt-default-rtdb-export.json

+{
+  "overview" : {
+    "IDG1" : {
+      "amplitude" : 1001,
+      "breitengrad" : 49.5,
+      "ip" : "10.00.00.001",
+      "laengengrad" : 11.5,
+      "timestamp" : 1113456789,
+      "vibration" : true
+    },
+    "IDG2" : {
+      "amplitude" : 200,
+      "breitengrad" : 40.70064147511923,
+      "ip" : "20.00.00.000",
+      "laengengrad" : -73.99376799797778,
+      "timestamp" : 1203456789,
+      "vibration" : false
+    },
+    "IDG3" : {
+      "amplitude" : 30,
+      "breitengrad" : -33.93157129193122,
+      "ip" : "30.00.00.000",
+      "laengengrad" : 18.39666975233824,
+      "timestamp" : 1303456789,
+      "vibration" : false
+    },
+    "IDG4" : {
+      "amplitude" : 4,
+      "breitengrad" : -33.40763257191139,
+      "ip" : "40.00.00.000",
+      "laengengrad" : -70.61870273653996,
+      "timestamp" : 1403456789,
+      "vibration" : false
+    }
+  }
+}

app/build.gradle

 plugins {
     id 'com.android.application'
+    id 'com.google.gms.google-services'
 }
 
 android {
     implementation 'com.google.android.material:material:1.3.0'
     implementation 'androidx.constraintlayout:constraintlayout:2.0.4'
     implementation 'com.google.android.gms:play-services-maps:17.0.1'
+    implementation 'com.google.firebase:firebase-database:20.0.0'
     testImplementation 'junit:junit:4.+'
     androidTestImplementation 'androidx.test.ext:junit:1.1.2'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'
     implementation "com.google.android.gms:play-services-location:15.0.1" //Important to find the location from the device
+    implementation platform('com.google.firebase:firebase-bom:28.1.0')
 }

app/google-services.json

+{
+  "project_info": {
+    "project_number": "1097743535942",
+    "firebase_url": "https://arontestprojekt-default-rtdb.europe-west1.firebasedatabase.app",
+    "project_id": "arontestprojekt",
+    "storage_bucket": "arontestprojekt.appspot.com"
+  },
+  "client": [
+    {
+      "client_info": {
+        "mobilesdk_app_id": "1:1097743535942:android:527888c66e66b847d29f47",
+        "android_client_info": {
+          "package_name": "com.example.myapplication1fb"
+        }
+      },
+      "oauth_client": [
+        {
+          "client_id": "1097743535942-ajbqq8gjc565pj2c2j5qtlskoskevf6o.apps.googleusercontent.com",
+          "client_type": 3
+        }
+      ],
+      "api_key": [
+        {
+          "current_key": "AIzaSyCwR1_JUNHQznkwcDjx5mngPJuqktBKFeM"
+        }
+      ],
+      "services": {
+        "appinvite_service": {
+          "other_platform_oauth_client": [
+            {
+              "client_id": "1097743535942-ajbqq8gjc565pj2c2j5qtlskoskevf6o.apps.googleusercontent.com",
+              "client_type": 3
+            }
+          ]
+        }
+      }
+    },
+    {
+      "client_info": {
+        "mobilesdk_app_id": "1:1097743535942:android:fba2ee9540898b84d29f47",
+        "android_client_info": {
+          "package_name": "com.example.myapplicationf2"
+        }
+      },
+      "oauth_client": [
+        {
+          "client_id": "1097743535942-ajbqq8gjc565pj2c2j5qtlskoskevf6o.apps.googleusercontent.com",
+          "client_type": 3
+        }
+      ],
+      "api_key": [
+        {
+          "current_key": "AIzaSyCwR1_JUNHQznkwcDjx5mngPJuqktBKFeM"
+        }
+      ],
+      "services": {
+        "appinvite_service": {
+          "other_platform_oauth_client": [
+            {
+              "client_id": "1097743535942-ajbqq8gjc565pj2c2j5qtlskoskevf6o.apps.googleusercontent.com",
+              "client_type": 3
+            }
+          ]
+        }
+      }
+    },
+    {
+      "client_info": {
+        "mobilesdk_app_id": "1:1097743535942:android:34888690bd5c9564d29f47",
+        "android_client_info": {
+          "package_name": "de.edotzlaff.schockwelle"
+        }
+      },
+      "oauth_client": [
+        {
+          "client_id": "1097743535942-ajbqq8gjc565pj2c2j5qtlskoskevf6o.apps.googleusercontent.com",
+          "client_type": 3
+        }
+      ],
+      "api_key": [
+        {
+          "current_key": "AIzaSyCwR1_JUNHQznkwcDjx5mngPJuqktBKFeM"
+        }
+      ],
+      "services": {
+        "appinvite_service": {
+          "other_platform_oauth_client": [
+            {
+              "client_id": "1097743535942-ajbqq8gjc565pj2c2j5qtlskoskevf6o.apps.googleusercontent.com",
+              "client_type": 3
+            }
+          ]
+        }
+      }
+    }
+  ],
+  "configuration_version": "1"
+}

app/src/main/AndroidManifest.xml

 
     <application
         android:allowBackup="true"
-        android:icon="@mipmap/ic_launcher"
+        android:icon="@mipmap/schockicon"
         android:label="@string/app_name"
-        android:roundIcon="@mipmap/ic_launcher_round"
+        android:roundIcon="@mipmap/schockicon"
         android:supportsRtl="true"
         android:theme="@style/Theme.Schockwelle">
 

app/src/main/java/de/edotzlaff/schockwelle/Devices.java

+package de.edotzlaff.schockwelle;
+
+public class Devices {
+    private String ip;
+    private boolean vibration;
+    private long timestamp;
+    private double breitengrad;
+    private double laengengrad;
+    private int amplitude;
+
+    public Devices() {
+
+    }
+
+    public Devices(String ip, boolean vibration, long timestamp, double breitengrad, double laengengrad, int amplitude) {
+        this.ip = ip;
+        this.vibration = vibration;
+        this.timestamp = timestamp;
+        this.breitengrad = breitengrad;
+        this.laengengrad = laengengrad;
+        this.amplitude = amplitude;
+    }
+
+    public String getIp() {
+        return ip;
+    }
+    public void setIp(String ip) {
+        this.ip = ip;
+    }
+
+
+    public boolean isVibration() {
+        return vibration;
+    }
+    public void setVibration(boolean vibration) {
+        this.vibration = vibration;
+    }
+
+
+    public long getTimestamp() {
+        return timestamp;
+    }
+    public void setTimestamp(long timestamp) {
+        this.timestamp = timestamp;
+    }
+
+
+    public double getBreitengrad() {
+        return breitengrad;
+    }
+    public void setBreitengrad(double breitengrad) {
+        this.breitengrad = breitengrad;
+    }
+
+
+    public double getLaengengrad() {
+        return laengengrad;
+    }
+    public void setLaengengrad(double laengengrad) {
+        this.laengengrad = laengengrad;
+    }
+
+
+    public int getAmplitude() {
+        return amplitude;
+    }
+    public void setAmplitude(int amplitude) {
+        this.amplitude = amplitude;
+    }
+}

app/src/main/java/de/edotzlaff/schockwelle/EarthquakeMapsActivity.java

 import android.content.pm.PackageManager;
 import android.location.Location;
 import android.os.Bundle;
+import android.os.SystemClock;
 import android.util.Log;
 import android.widget.Toast;
 
 import com.google.android.gms.maps.model.MarkerOptions;
 import com.google.android.gms.tasks.OnCompleteListener;
 import com.google.android.gms.tasks.Task;
+import com.google.firebase.database.DataSnapshot;
+import com.google.firebase.database.DatabaseError;
+import com.google.firebase.database.DatabaseReference;
+import com.google.firebase.database.FirebaseDatabase;
+import com.google.firebase.database.ValueEventListener;
 
 public class EarthquakeMapsActivity extends FragmentActivity implements OnMapReadyCallback {
 
     private GoogleMap mMap;
     private FusedLocationProviderClient mFusedLocationProviderClient;
 
+    private DatabaseReference mDatenbank;
+
+    private double breitengrad;
+    private double laengengrad;
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_earthquake_maps);
 
+        getDataBaseValues();    //TODO Edward: Nur als Anmerkung, diese Methode erfolgt damit deine Methode getDeviceLocation Koordinaten aus der DB bekommt
         getLocationPermission();
     }
 
 
     private void getDeviceLocation(){
         mFusedLocationProviderClient = LocationServices.getFusedLocationProviderClient(this);
-
         try {
             if (mLocationPermissionsGranted){
                 final Task location = mFusedLocationProviderClient.getLastLocation();
                     @Override
                     public void onComplete(@NonNull Task task) {
                         if (task.isSuccessful()){
-
-                            Location currentLocation = (Location) task.getResult(); //TODO Aron hier erhält die Anwendung die GPS Positionen
+                            Location currentLocation = (Location) task.getResult();
+                            currentLocation.setLatitude(breitengrad);                   //TODO Edward: Hier werden beispielweise Koordinaten aus der Datenbank verwendet für Gerät IDG1
+                            currentLocation.setLongitude(laengengrad);
                             moveCamera(new LatLng(currentLocation.getLatitude(), currentLocation.getLongitude()),15f);
-
                         }
                         else{
                             Toast.makeText(EarthquakeMapsActivity.this, "Current Location unavailable", Toast.LENGTH_SHORT).show();
         mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latlng, zoom));
     }
 
+    public void getDataBaseValues()
+    {
+        mDatenbank = FirebaseDatabase.getInstance().getReference();
+        mDatenbank.addValueEventListener(new ValueEventListener() {
+            @Override
+            public void onDataChange(@NonNull DataSnapshot snapshot) {
+                processDataBaseValues(snapshot);                           //Daten Snapshot, Übergabe an processDataBaseValues
+            }
+            @Override
+            public void onCancelled(@NonNull DatabaseError error) {
+                getDataBaseFailure(error);
+            }
+        });
+    }
+
+    public void processDataBaseValues (DataSnapshot data)
+    {
+        //####### Hier wird beispielweise mit IDG1 gearbeitet, sollte aber klüger ausgearbeitet werden #######:
+        String breitengradString = data.child("overview").child("IDG1").child("breitengrad").getValue().toString();     //TODO Aron/Team: Idee für passende ID je nach zugreifendem Gerät ==> Hardcoded oder flexibel?
+        String laengengradString = data.child("overview").child("IDG1").child("laengengrad").getValue().toString();
+        breitengrad = Double.parseDouble(breitengradString);
+        laengengrad = Double.parseDouble(laengengradString);
+    }
 
-    //TODO Aron Daten an DB senden
+    public void getDataBaseFailure (DatabaseError error)
+    {
+        System.out.println("Fehler");
+        Log.w("Datenbankfehler", error.toException());
+    }
+
+
+    //TODO Edward: Hier ist eine beispielhafte Methode mit der du Werte in der Datenbank setzen kannst
+    public void setDataBaseValues()
+    {
+        mDatenbank = FirebaseDatabase.getInstance().getReference();
+        mDatenbank.child("overview").child("IDG1").child("ip").setValue("10.00.00.001");
+        mDatenbank.child("overview").child("IDG1").child("vibration").setValue(true);
+        mDatenbank.child("overview").child("IDG1").child("timestamp").setValue(1113456789);
+        mDatenbank.child("overview").child("IDG1").child("breitengrad").setValue(49.5);
+        mDatenbank.child("overview").child("IDG1").child("laengengrad").setValue(11.5);
+        mDatenbank.child("overview").child("IDG1").child("amplitude").setValue(1001);
+    }
 }

app/src/main/java/de/edotzlaff/schockwelle/MainActivity.java

 package de.edotzlaff.schockwelle;
 
+import androidx.annotation.NonNull;
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.fragment.app.FragmentActivity;
 
 
 import com.google.android.gms.common.ConnectionResult;
 import com.google.android.gms.common.GoogleApiAvailability;
+import com.google.firebase.database.DataSnapshot;
+import com.google.firebase.database.DatabaseError;
+import com.google.firebase.database.DatabaseReference;
+import com.google.firebase.database.FirebaseDatabase;
+import com.google.firebase.database.ValueEventListener;
 
 public class MainActivity extends FragmentActivity {
 
     private static final String TAG = "MainActivity";
     private static final int ERROR_DIALOG_REQUEST = 9001;
-
+    private DatabaseReference mDatenbank;
 
 
     @Override
         if (isServiceOK()){
             init();
         }
+
+        deviceInitDataBase();   //TODO Edward: Mit dieser Methode wird beim Starten der App die DB mit, vorerst festen, Werten für alle IDG 1-4 initialiert
     }
 
     private void init(){
                 startActivity(intent);
             }
         });
-
-
     }
 
-
     public boolean isServiceOK(){
         Log.d(TAG, "isServicesOK(): checking google services version");
 
         }
         return false;
     }
+
+    public void deviceInitDataBase()
+    {
+        mDatenbank = FirebaseDatabase.getInstance().getReference();
+        Devices d1 = new Devices("10.00.00.000", false, 1103456789, 49.45470362290784, 11.151032510281498, 1000);
+        Devices d2 = new Devices("20.00.00.000", false, 1203456789, 40.70064147511923, -73.993767997977787, 200);
+        Devices d3 = new Devices("30.00.00.000", false, 1303456789, -33.93157129193122, 18.39666975233824, 30);
+        Devices d4 = new Devices("40.00.00.000", false, 1403456789, -33.40763257191139, -70.61870273653996, 4);
+        mDatenbank.child("overview").child("IDG1").setValue(d1);
+        mDatenbank.child("overview").child("IDG2").setValue(d2);
+        mDatenbank.child("overview").child("IDG3").setValue(d3);
+        mDatenbank.child("overview").child("IDG4").setValue(d4);
+        getDataBaseValues();
+    }
+
+    public void getDataBaseValues()
+    {
+        mDatenbank.addValueEventListener(new ValueEventListener() {
+            @Override
+            public void onDataChange(@NonNull DataSnapshot snapshot) {
+                processDataBaseValues(snapshot);                           //Daten - Snapshot, Übergabe an Methode DataChangeProtocol
+            }
+            @Override
+            public void onCancelled(@NonNull DatabaseError error) {
+                getDataBaseFailure(error);
+            }
+        });
+    }
+
+    public void processDataBaseValues (DataSnapshot data)
+    {
+        for (int i = 1; i<=4; i++)  //Für alle IDG 1-4 werden Werte ausgegeben
+        {
+            //####### Auslesen für String-Werte #######:
+            String ipAdresse = data.child("overview").child("IDG" + i).child("ip").getValue().toString();
+
+            //####### Auslesen für boolean-Werte #######:
+            String vibrationString = data.child("overview").child("IDG" + i).child("vibration").getValue().toString();
+            boolean vibration;
+            if(vibrationString == "true"){
+                vibration = true;
+            }else{
+                vibration = false;
+            }
+
+            //####### Auslesen für double-Werte #######:
+            String breitengradString = data.child("overview").child("IDG" + i).child("breitengrad").getValue().toString();
+            String laengengradString = data.child("overview").child("IDG" + i).child("laengengrad").getValue().toString();
+            double breitengrad = Double.parseDouble(breitengradString);
+            double laengengrad = Double.parseDouble(laengengradString);
+
+            //####### Auslesen für long-Werte #######:
+            String timestampString = data.child("overview").child("IDG" + i).child("timestamp").getValue().toString();
+            long timestamp = Long.parseLong(timestampString);
+
+            //####### Auslesen für ing-Werte #######:
+            String amplitudeString = data.child("overview").child("IDG" + i).child("amplitude").getValue().toString();
+            int amplitude = Integer.parseInt(amplitudeString);
+
+            //####### Optional zur Kontrolle #######:
+            /*
+            System.out.println("IDG" + i + " -          IP:" + data.child("overview").child("IDG" + i).child("ip").getValue().toString());
+            System.out.println("IDG" + i + " -   Vibration:" + data.child("overview").child("IDG" + i).child("vibration").getValue().toString());
+            System.out.println("IDG" + i + " - Zeitstempel:" + data.child("overview").child("IDG" + i).child("timestamp").getValue().toString());
+            System.out.println("IDG" + i + " - Breitengrad:" + data.child("overview").child("IDG" + i).child("breitengrad").getValue().toString());
+            System.out.println("IDG" + i + " - Laengengrad:" + data.child("overview").child("IDG" + i).child("laengengrad").getValue().toString());
+            System.out.println("IDG" + i + " -   Amplitude:" + data.child("overview").child("IDG" + i).child("amplitude").getValue().toString());
+            */
+        }
+    }
+
+    public void getDataBaseFailure (DatabaseError error)
+    {
+        System.out.println("Fehler");
+        Log.w("Datenbankfehler", error.toException());
+    }
 }

app/src/main/java/de/edotzlaff/schockwelle/SensorMapsActivity.java

 package de.edotzlaff.schockwelle;
 
+import androidx.annotation.NonNull;
 import androidx.fragment.app.FragmentActivity;
 
 import android.location.Location;
 import android.os.Bundle;
+import android.os.SystemClock;
+import android.util.Log;
 import android.widget.TextView;
 
 import com.google.android.gms.maps.CameraUpdateFactory;
 import com.google.android.gms.maps.SupportMapFragment;
 import com.google.android.gms.maps.model.LatLng;
 import com.google.android.gms.maps.model.MarkerOptions;
+import com.google.firebase.database.DataSnapshot;
+import com.google.firebase.database.DatabaseError;
+import com.google.firebase.database.DatabaseReference;
+import com.google.firebase.database.FirebaseDatabase;
+import com.google.firebase.database.ValueEventListener;
 
 import org.w3c.dom.Text;
 
 public class SensorMapsActivity extends FragmentActivity implements OnMapReadyCallback {
 
     private GoogleMap mMap;
+    private DatabaseReference mDatenbank;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         TextView tv= (TextView) findViewById(R.id.txtSensor);
 
         initMap();
-
     }
 
     void initMap(){
         LatLng sydney = new LatLng(-34, 151);
         mMap.addMarker(new MarkerOptions().position(sydney).title("Marker in Sydney"));
         mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));
+    }
 
+    //TODO Edward: Mit Methode getDataBaseValues werden die Werte in der DB abgefragt. In Methode processDataBaseValues werden diese beispielhaft ausgelesen. Kann nach Bedarf angepasst werden.
+    public void getDataBaseValues()
+    {
+        mDatenbank = FirebaseDatabase.getInstance().getReference();
+        mDatenbank.addValueEventListener(new ValueEventListener() {
+            @Override
+            public void onDataChange(@NonNull DataSnapshot snapshot) {
+                processDataBaseValues(snapshot);                           //Daten - Snapshot, Übergabe an Methode DataChangeProtocol
+            }
+            @Override
+            public void onCancelled(@NonNull DatabaseError error) {
+                getDataBaseFailure(error);
+            }
+        });
+    }
 
+    public void processDataBaseValues (DataSnapshot data)
+    {
+        for (int i = 1; i<=4; i++)  //Für alle IDG 1-4 werden Werte ausgegeben
+        {
+            //####### Auslesen für String-Werte #######:
+            String ipAdresse = data.child("overview").child("IDG" + i).child("ip").getValue().toString();
+
+            //####### Auslesen für boolean-Werte #######:
+            String vibrationString = data.child("overview").child("IDG" + i).child("vibration").getValue().toString();
+            boolean vibration;
+            if(vibrationString == "true"){
+                vibration = true;
+            }else{
+                vibration = false;
+            }
+
+            //####### Auslesen für double-Werte #######:
+            String breitengradString = data.child("overview").child("IDG" + i).child("breitengrad").getValue().toString();
+            String laengengradString = data.child("overview").child("IDG" + i).child("laengengrad").getValue().toString();
+            double breitengrad = Double.parseDouble(breitengradString);
+            double laengengrad = Double.parseDouble(laengengradString);
+
+            //####### Auslesen für long-Werte #######:
+            String timestampString = data.child("overview").child("IDG" + i).child("timestamp").getValue().toString();
+            long timestamp = Long.parseLong(timestampString);
+
+            //####### Auslesen für ing-Werte #######:
+            String amplitudeString = data.child("overview").child("IDG" + i).child("amplitude").getValue().toString();
+            int amplitude = Integer.parseInt(amplitudeString);
+
+            //####### Optional zur Kontrolle #######:
+            /*
+            System.out.println("IDG" + i + " -          IP:" + data.child("overview").child("IDG" + i).child("ip").getValue().toString());
+            System.out.println("IDG" + i + " -   Vibration:" + data.child("overview").child("IDG" + i).child("vibration").getValue().toString());
+            System.out.println("IDG" + i + " - Zeitstempel:" + data.child("overview").child("IDG" + i).child("timestamp").getValue().toString());
+            System.out.println("IDG" + i + " - Breitengrad:" + data.child("overview").child("IDG" + i).child("breitengrad").getValue().toString());
+            System.out.println("IDG" + i + " - Laengengrad:" + data.child("overview").child("IDG" + i).child("laengengrad").getValue().toString());
+            System.out.println("IDG" + i + " -   Amplitude:" + data.child("overview").child("IDG" + i).child("amplitude").getValue().toString());
+            */
+        }
+    }
 
+    public void getDataBaseFailure (DatabaseError error)
+    {
+        System.out.println("Fehler");
+        Log.w("Datenbankfehler", error.toException());
     }
 
-    //TODO Aron Daten von DB abfragen
     //TODO Edward Distanz zwischen zwei Punkten berechnen
     //TODO Edward Dauer für Timer berechnen bis Smartphone vibriert
     /*
         return distanceInMeters;
     }
 */
-
-
 }

app/src/main/res/layout/activity_main.xml

         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:id="@+id/btnEarthquake"
-        android:text="Generate Earthquake"
+        android:text="@string/generate_earthquake"
         android:layout_centerVertical="true"
         android:layout_centerHorizontal="true" />
 
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:id="@+id/btnSensor"
-        android:text="Be a Sensor"
+        android:text="@string/be_a_sensor"
         android:layout_centerHorizontal="true"
         android:layout_below="@id/btnEarthquake"/>
 

app/src/main/res/values/strings.xml

     <string name="app_name">Schockwelle</string>
     <string name="title_activity_earthquake_maps">Map</string>
     <string name="title_activity_sensor_maps">Map</string>
+    <string name="be_a_sensor">Be a Sensor</string>
+    <string name="generate_earthquake">Generate Earthquake</string>
 </resources>

build.gradle

     }
     dependencies {
         classpath "com.android.tools.build:gradle:4.1.3"
+        classpath 'com.google.gms:google-services:4.3.8'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files