Play functions code added

src/main/java/device/usbPlayer/UsbPlayer.java

@@ -57,15 +57,35 @@ public class UsbPlayer implements Device {
         return Lautstaerke;
     }
 
-    @Override
-    public void louder() {
-        if(Lautstaerke < 100) {
-            Lautstaerke += 1;
-        } else {
-            Lautstaerke = 100;
+    //*********constructure********
+    public UsbPlayer() {
+        super();
+        isDefect = false;
+        isConnected = true;
+        Playlist.add("Musik 01.mp3");
+        Playlist.add("Musik 02.mp3");
+        Playlist.add("Musik 03.mp3");
+        playTrack = Playlist.get(0);
+
+    }
+    //**********search method*************
+    private boolean isAllAudio() {
+
+        String song = "";
+        boolean flag = true;
+
+        for (int i = 0; i < Playlist.size(); i++) {
+            song = Playlist.get(i).substring(Playlist.get(i).length() - 4);
+            if (song.equals(".mp3") | song.equals(".mp4") | song.equals(".wav")) {
+                flag = true;
+            } else {
+                flag = false;
+                break;
+            }
         }
+        return flag;
     }
-    //*********setters und getters********
+    //**********search method*************
     @Override
     public void quieter() {
         if(Lautstaerke > 0) {
@@ -75,6 +95,15 @@ public class UsbPlayer implements Device {
         }
     }
 
+    @Override
+    public void louder() {
+        if(Lautstaerke < 100) {
+            Lautstaerke += 1;
+        } else {
+            Lautstaerke = 100;
+        }
+    }
+
     @Override
     public int getVolume() {
         return 0;
@@ -108,7 +137,29 @@ public class UsbPlayer implements Device {
 
     @Override
     public String play() {
-        return null;
+        String result = "USB : ";
+        if (isConnected == true) {
+            result += "connected,";
+            if (isDefect == false) {
+                result += "working";
+                if (this.Playlist.size() != 0) {
+                    result += ",have a list";
+                    if (this.isAllAudio()) {
+                        result += ",Audio";
+                        if (!playTrack.equals(""))
+                            result += ",point to a track.";
+                        else
+                            result += ",doesn't point to a track.";
+                    } else {
+                        result += ",not Audio.";
+                    }
+                } else result += ",have no list.";
+            } else {
+                result += "not working.";
+            }
+        } else result = "not connected.";
+        return result;
+
     }
 
 }