warning: [unchecked] unchecked conversion duaring compile

warning: [unchecked] unchecked conversion duaring compile

I have this Java code which lunches java thread:
public void start(Stage primaryStage)
{
// TODO when Java 8 is released use this to set default Skin
//setUserAgentStylesheet(STYLESHEET_CASPIAN);
final Task<ObservableList<String>> friendTask = new Task()
{
@Override
protected ObservableList<String> call() throws
InterruptedException
{
ObservableList<String> foundFriends =
FXCollections.<String>observableArrayList();
ObservableList<String> availableFriends =
FXCollections.observableArrayList("Network
Module", "User Module", "User Interface", "User
Controls");
updateMessage("Loading Modules . . .");
for (int i = 0; i < availableFriends.size(); i++)
{
Thread.sleep(250);
updateProgress(i + 1, availableFriends.size());
String nextFriend = availableFriends.get(i);
foundFriends.add(nextFriend);
updateMessage("Loading Modules . . . Loading " +
nextFriend);
}
updateMessage("All Modules are loaded.");
Thread.sleep(1500);
return foundFriends;
}
};
showSplash(primaryStage, friendTask);
new Thread(friendTask).start();
initMainStage(primaryStage);
}
I can compile the code but I get this warning message:
Compiling 26 source files to
/home/rcbandit/Desktop/test/DX-57DC/build/classes
/home/rcbandit/Desktop/test/DX-57DC/src/com/dx57dc/main/DX57DC.java:75:
warning: [unchecked] unchecked conversion
final Task<ObservableList<String>> friendTask = new Task()
required: Task<ObservableList<String>>
found: <anonymous Task>
/home/rcbandit/Desktop/test/DX-57DC/src/com/dx57dc/main/DX57DC.java:139:
warning: [unchecked] unchecked call to addListener(ChangeListener<? super
T>) as a member of the raw type ObservableValue
task.stateProperty().addListener(new ChangeListener<Worker.State>()
where T is a type-variable:
T extends Object declared in interface ObservableValue
2 warnings
Can you tell me how I can fix this?