Exception in listener attached to multiple buttons

Question

Okay, So I am developing an in house barcode scanner for my company to use when we move computers and equipment. I am currently almost through setting up the Zxing Barcode Scanner Via Intent after some trial and error.

Here is what I'm trying to do.

Next to three EditText fields I have Three ImageButtons that when clicked, implement the BarcodeScanner, once scanned returns the value and inputs the value into the EditText field. I was able to do it successfully using one "listener" corresponding to one ImageButton. But after trying to use multiple Buttons with one listener, it calls the barcode scanner but crashes when trying to return the barcode value.

The Debugger shows the main Thread Suspended and I have to resume the debugger twice before the RuntimeException error appears in Logcat.

here's the error log from LogCat:

07-17 17:38:49.251: E/AndroidRuntime(30942): java.lang.RuntimeException: Unable to resume activity {com.fmi.inventory/com.fmi.inventory.MainActivity}: java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=49374, result=-1, data=Intent { act=com.google.zxing.client.android.SCAN flg=0x80000 (has extras) }} to activity {com.fmi.inventory/com.fmi.inventory.MainActivity}: java.lang.NullPointerException

Here is my MainActivity:

package com.fmi.inventory;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.EditText;
import android.widget.ImageButton;

public class MainActivity extends Activity {

    ImageButton button;
    ImageButton button1;
    ImageButton button2;
    EditText editField;
    Activity activity;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        activity = this;
        button = (ImageButton)findViewById(R.id.scanCubeID);
        button1 = (ImageButton)findViewById(R.id.scanEmployeeID);
        button2 = (ImageButton)findViewById(R.id.scanConfigID);
        button.setOnClickListener(listener);
        button1.setOnClickListener(listener);
        button2.setOnClickListener(listener);

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }

    @Override
    public void onResume() {
        super.onResume();

    }

    public void setCubeClick(){
        editField = (EditText)findViewById(R.id.editCubeID);
    }

    public void setEmployeeClick(){
        editField = (EditText)findViewById(R.id.editEmployeeID);
    }

    public void setConfigClick(){
        editField = (EditText)findViewById(R.id.editConfigID);
    }

    private View.OnClickListener listener = new View.OnClickListener() {
        public void onClick(View v) {
            IntentIntegrator integrator = new IntentIntegrator(activity);
            integrator.initiateScan();

        }
    };

    public void onActivityResult(int requestCode, int resultCode, Intent intent) {
        switch (requestCode) {
        case IntentIntegrator.REQUEST_CODE:
            if (resultCode == Activity.RESULT_OK) {

                IntentResult intentResult = IntentIntegrator
                        .parseActivityResult(requestCode, resultCode, intent);

                if (intentResult != null) {

                    String contents = intentResult.getContents();
                    String format = intentResult.getFormatName();
                    this.editField.setText(contents);
                    // this.elemQuery.setText(contents);
                    //this.resume = false;
                    Log.d("SEARCH_EAN", "OK, EAN: " + contents + ", FORMAT: "
                            + format);
                } else {
                    Log.e("SEARCH_EAN", "IntentResult je NULL!");
                }
            } else if (resultCode == Activity.RESULT_CANCELED) {
                Log.e("SEARCH_EAN", "CANCEL");
            }
        }
    }
}

Here is my layout .xml for MainActivity

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <EditText
        android:id="@+id/editCubeID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/scanEmployeeID"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_toLeftOf="@+id/scanCubeID"
        android:ems="10"
        android:hint="@string/edit_cubeid" >

        <requestFocus />
    </EditText>

    <EditText
        android:id="@+id/editEmployeeID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_above="@+id/scanConfigID"
        android:layout_alignParentLeft="true"
        android:layout_alignRight="@+id/editCubeID"
        android:layout_below="@+id/editCubeID"
        android:ems="10"
        android:hint="@string/edit_employeeid" />

    <EditText
        android:id="@+id/editConfigID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@+id/scanConfigID"
        android:layout_alignParentLeft="true"
        android:layout_alignRight="@+id/editEmployeeID"
        android:layout_below="@+id/editEmployeeID"
        android:ems="10"
        android:hint="@string/edit_configid" />

    <ImageButton
        android:id="@+id/scanCubeID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:contentDescription="@string/desc"
        android:layout_alignParentTop="true"
        android:src="@drawable/ic_action_scan"
        android:onClick="onClick" />

    <ImageButton
        android:id="@+id/scanEmployeeID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:contentDescription="@string/desc"
        android:layout_below="@+id/scanCubeID"
        android:src="@drawable/ic_action_scan"
        android:onClick="onClick" />

    <ImageButton
        android:id="@+id/scanConfigID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:contentDescription="@string/desc"
        android:layout_below="@+id/scanEmployeeID"
        android:src="@drawable/ic_action_scan"
        android:onClick="onClick" />

    <Button
        android:id="@+id/submit"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/editConfigID"
        android:text="@string/button_continue" />

</RelativeLayout>

Answer 1

When your Activity come in onActivityResult after scanning.You are accessing editField but it is NULL.

as you never Initialized it..

You are Initializing them in setCubeClick, setEmployeeClick or setConfigClick,

But I am affraid they never called..Try to Initialize them in OnCreat