# ControlP5 - java.lang.NullPointerException

**URL:** https://discourse.processing.org/t/controlp5-java-lang-nullpointerexception/13974
**Category:** Libraries
**Created:** [September 13, 2019, 6:53pm UTC](https://discourse.processing.org/t/controlp5-java-lang-nullpointerexception/13974 "2019-09-13T18:53:06Z")
**Posts on this page:** 2
**Page:** 1

<div class="post-metadata">

### Author: ![Rammstan](https://avatars.discourse-cdn.com/v4/letter/r/e0b2c6/32.png) [@Rammstan](https://discourse.processing.org/u/Rammstan)
#### Post date: [September 13, 2019, 6:53pm UTC](https://discourse.processing.org/t/controlp5-java-lang-nullpointerexception/13974/1 "2019-09-13T18:53:06Z")

</div>

Hello,

Similar to [this](https://forum.processing.org/one/topic/controlp5-got-error-that-i-can-t-understand.html) post, i have an error.  
I know the problem is `path = controlP5.get(Textfield.class,"File").getText();`

But i don’t understand why. All variables are declared at right time… i think 😛

It’s not blocking but annoying in the terminal

Thanks for help.

```auto
sept. 13, 2019 8:33:12 PM controlP5.ControlBroadcaster printMethodError
GRAVE: An error occured while forwarding a Controller event, please check your code at controlEvent
java.lang.reflect.InvocationTargetException
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at controlP5.ControlBroadcaster.invokeMethod(Unknown Source)
	at controlP5.ControlBroadcaster.broadcast(Unknown Source)
	at controlP5.Controller.broadcast(Unknown Source)
	at controlP5.Button.setValue(Unknown Source)
	at ocm_app.createGui(ocm_app.java:45)
	at ocm_app.setup(ocm_app.java:24)
	at processing.core.PApplet.handleDraw(PApplet.java:2425)
	at processing.awt.PSurfaceAWT$12.callDraw(PSurfaceAWT.java:1547)
	at processing.core.PSurfaceNone$AnimationThread.run(PSurfaceNone.java:313)
Caused by: java.lang.NullPointerException
	at ocm_app.controlEvent(ocm_app.java:63)
	... 13 more

```

here is my code:  
main:

```auto
boolean smartphone = true;
String path;
void setup(){
  size(600,400);
  
  createGui();
}

void draw(){
}

```

gui:

```auto
import controlP5.*; // import controlP5 library
ControlP5 controlP5; // controlP5 object

void createGui() {
  controlP5 = new ControlP5(this);
  int x_control = int(width * 0.01);
  int y_control = int(height *0.95);
  int w_button = int(width * 0.1);
  int h_button = int(width * 0.03);

 controlP5.addButton("bt_connect")
    .setValue(0)
    .setPosition(x_control, y_control)
    .setSize( w_button, h_button);
  controlP5.addButton("open")
    .setValue(0)
    .setPosition(x_control*2 + w_button, y_control)
    .setSize( w_button, h_button);
  controlP5.addTextfield("File")
    .setValue("test.txt")
    .setPosition(x_control*3 + w_button*2, y_control)
    .setSize(w_button, h_button)
    .setInputFilter(ControlP5.STRING);
}

void controlEvent(ControlEvent theEvent) {
  if (theEvent.isController()) { 

    print("control event from : "+theEvent.getController().getName());
    println(", value : "+theEvent.getController().getValue());
    
    if (theEvent.getController().getName()=="open") {     
      path = controlP5.get(Textfield.class,"File").getText();
    }
  }
}

```

---

<div class="post-metadata">

### Author: ![kll](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.processing.org/kll/32/964_2.png) [@kll](https://discourse.processing.org/u/kll)
#### Post date: [September 14, 2019, 4:38am UTC](https://discourse.processing.org/t/controlp5-java-lang-nullpointerexception/13974/2 "2019-09-14T04:38:05Z")

</div>

i think the point it that CP5  
fires events at startup  
BUT at  
addButton OPEN  
addTextfield FILE  
not declared/happened.

* * *

move it UP