$http.get(url).success(callback-function);

public class HTTPCaller {
public HTTPCaller() {

}

public static <T> HTTPCall<T> get(String url,Class<T> clazz, HTTPCallListener<T> listener) {
HTTPCall<T> call=new HTTPCall<T>();
call.setListener(listener);
call.setMethod("get");
call.setTargetClass(clazz);
call.setUrl(url);
return call;
}
}

public interface HTTPCallListener<T> {
public void processAsyncResponse(T response);
}

public class HTTPCall<T> {
private String method = "get";
private String url = "";
private String params = "";
private ObjectMapper mapper = new ObjectMapper();
private Class<T> targetClass=null;
private T result=null;
private HTTPCallListener<T> listener=null;

public HTTPCall() {
}

public void callAsync(){
HTTPCallTask task=new HTTPCallTask(this);
new Thread(task).start();
}

public T call() {
this.result=null;
try {
URL url = new URL(this.url);
System.out.println("call url: " + url.toString());
this.result = mapper.readValue(url, this.targetClass);
}
catch (Exception e) {
e.printStackTrace();
}
return this.result;
}

public void callListener(){
if(this.listener!=null){
this.listener.processAsyncResponse(this.result);
}
}

public String getMethod() {
return method;
}

public void setMethod(String method) {
this.method = method;
}

public String getUrl() {
return url;
}

public void setUrl(String url) {
this.url = url;
}

public String getParams() {
return params;
}

public void setParams(String params) {
this.params = params;
}

public Class<T> getTargetClass() {
return targetClass;
}

public void setTargetClass(Class<T> targetClass) {
this.targetClass = targetClass;
}

public HTTPCallListener<T> getListener() {
return listener;
}

public void setListener(HTTPCallListener<T> listener) {
this.listener = listener;
}
}

public class HTTPCallTask extends Task<Object>{
private HTTPCall<?> call=null;

public HTTPCallTask(HTTPCall<?> call) {
this.call=call;
}

@Override
protected Object call() throws Exception {
this.call.call();
return null;
}

@Override
protected void succeeded() {
this.call.callListener();
}
}

HTTPCaller.get(url,resultClass,listener).callAsync();