Unable to Instantiate activity ComponentInfo - Android

Question

I have read several errors of this kind, but I do not find a solution to my particular problem. My activities are all added to my manifest, and I did not start the emulator from an abstract class. My app used to work, until I tried to add spinners to it (which I probably did not do right). I run the app and it crashes before it even opens. Any idea what is wrong? I am a beginner, so please share plain language, thanks very much.

So here is my main activity:

package com.noni.gridimagesearch;

import java.util.ArrayList;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.GridView;
import android.widget.Toast;

import com.loopj.android.http.AsyncHttpClient;
import com.loopj.android.http.JsonHttpResponseHandler;

public class SearchActivity extends Activity {
    EditText etQuery;
    GridView gvResults; 
    Button btnSearch;
    ArrayList<ImageResult> imageResults = new ArrayList<ImageResult>();
    ImageResultArrayAdapter imageAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_search);
        setupViews();
        imageAdapter = new ImageResultArrayAdapter(this, imageResults);
        gvResults.setAdapter(imageAdapter);
        gvResults.setOnItemClickListener(new OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapter, View parent, 
                    int position, long rowId) {
                Intent i = new Intent(getApplicationContext(), 
                        ImageDisplayActivity.class);
                ImageResult imageResult = imageResults.get(position);
                i.putExtra("result", imageResult);
                startActivity(i);
            }
        });

        GridView gvResults = (GridView) findViewById(R.id.gvResults);
        gvResults.setOnScrollListener(new EndlessScrollListener() {
            @Override
            public void onLoadMore(int page, int TotalItemsCount) {
                customLoadMoreDataFromApi(page);
            }
        });

        setupAdvancedOptionsListener();

    } //end onCreate method

    Button advancedSearch = (Button) findViewById(R.id.advancedSearch);
    public void setupAdvancedOptionsListener() {
        advancedSearch.setOnClickListener(new OnClickListener() {
            public void onClick(View v){
                Intent i = new Intent (SearchActivity.this, AdvancedOptionsActivity.class);
                startActivity(i);
            }

        });
    }

    public void customLoadMoreDataFromApi(int offset) {

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.search, menu);
        return true;
    } 

    public void setupViews() {
        etQuery = (EditText) findViewById(R.id.etQuery);
        gvResults = (GridView) findViewById(R.id.gvResults);
        btnSearch = (Button) findViewById(R.id.btnSearch);  
    }

    public void onImageSearch(View v) {
        imageResults.clear();
        String query = etQuery.getText().toString();
        Toast.makeText(this, "Searching for " + query, Toast.LENGTH_SHORT).show();
        AsyncHttpClient client = new AsyncHttpClient();
        int offset = 0;
        client.get("https://ajax.googleapis.com/ajax/services/search/images?rsz=8&" +
        "start=" + offset + "&v=1.0&imgsz=medium&q=" + Uri.encode(query), 
                new JsonHttpResponseHandler() {
            @Override
            public void onSuccess(JSONObject response) {
                JSONArray imageJsonResults = null;
                try {
                    imageJsonResults = response.getJSONObject("responseData")
                            .getJSONArray("results");

                    imageAdapter.addAll(ImageResult
                            .fromJSONArray(imageJsonResults));
                    Log.d("DEBUG", imageResults.toString());
                } catch (JSONException e) {
                    e.printStackTrace();
                }
            }
        });
    } 

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

}

Here is my activity with the spinners:

package com.noni.gridimagesearch;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;

public class AdvancedOptionsActivity extends Activity implements AdapterView.OnItemSelectedListener {

    private Spinner colorFilter, imageSize, imageType;
    //private Button btnSubmit;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_advanced_options);

        colorFilter = (Spinner) findViewById(R.id.color_filter);
        ArrayAdapter<?> adapter = ArrayAdapter.createFromResource(this, 
                R.array.color_filter, android.R.layout.simple_spinner_item);
        colorFilter.setAdapter(adapter);
        colorFilter.setOnItemSelectedListener(this);

        imageSize = (Spinner) findViewById(R.id.image_size);
        ArrayAdapter<?> adapter2 = ArrayAdapter.createFromResource(this, 
                R.array.image_size, android.R.layout.simple_spinner_item);
        imageSize.setAdapter(adapter2);
        imageSize.setOnItemSelectedListener(this);

        imageType = (Spinner) findViewById(R.id.image_type);
        ArrayAdapter<?> adapter3 = ArrayAdapter.createFromResource(this, 
                R.array.image_type, android.R.layout.simple_spinner_item);
        imageType.setAdapter(adapter3);
        imageType.setOnItemSelectedListener(this);
    }   

    public void onItemSelected(AdapterView<?> adapterView, View view, int i,
            long l) {
        TextView myText = (TextView) view;
        Toast.makeText(this, "You selected " + myText.getText(), 
                Toast.LENGTH_SHORT).show();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.advanced_options, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

    @Override
    public void onNothingSelected(AdapterView<?> arg0) {
        // TODO Auto-generated method stub  
    }
}

Here is the LogCat:

04-01 06:43:26.638: E/AndroidRuntime(5247): FATAL EXCEPTION: main
04-01 06:43:26.638: E/AndroidRuntime(5247): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.noni.gridimagesearch/com.noni.gridimagesearch.SearchActivity}: java.lang.NullPointerException
04-01 06:43:26.638: E/AndroidRuntime(5247):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1983)
04-01 06:43:26.638: E/AndroidRuntime(5247):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
04-01 06:43:26.638: E/AndroidRuntime(5247):     at android.app.ActivityThread.access$600(ActivityThread.java:130)
04-01 06:43:26.638: E/AndroidRuntime(5247):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
04-01 06:43:26.638: E/AndroidRuntime(5247):     at android.os.Handler.dispatchMessage(Handler.java:99)
04-01 06:43:26.638: E/AndroidRuntime(5247):     at android.os.Looper.loop(Looper.java:137)
04-01 06:43:26.638: E/AndroidRuntime(5247):     at android.app.ActivityThread.main(ActivityThread.java:4745)
04-01 06:43:26.638: E/AndroidRuntime(5247):     at java.lang.reflect.Method.invokeNative(Native Method)
04-01 06:43:26.638: E/AndroidRuntime(5247):     at java.lang.reflect.Method.invoke(Method.java:511)
04-01 06:43:26.638: E/AndroidRuntime(5247):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
04-01 06:43:26.638: E/AndroidRuntime(5247):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
04-01 06:43:26.638: E/AndroidRuntime(5247):     at dalvik.system.NativeStart.main(Native Method)
04-01 06:43:26.638: E/AndroidRuntime(5247): Caused by: java.lang.NullPointerException
04-01 06:43:26.638: E/AndroidRuntime(5247):     at android.app.Activity.findViewById(Activity.java:1825)
04-01 06:43:26.638: E/AndroidRuntime(5247):     at com.noni.gridimagesearch.SearchActivity.<init>(SearchActivity.java:66)
04-01 06:43:26.638: E/AndroidRuntime(5247):     at java.lang.Class.newInstanceImpl(Native Method)
04-01 06:43:26.638: E/AndroidRuntime(5247):     at java.lang.Class.newInstance(Class.java:1319)
04-01 06:43:26.638: E/AndroidRuntime(5247):     at android.app.Instrumentation.newActivity(Instrumentation.java:1053)
04-01 06:43:26.638: E/AndroidRuntime(5247):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1974)
04-01 06:43:26.638: E/AndroidRuntime(5247):     ... 11 more

Here is my activity_search.xml:

<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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin" 
    tools:context=".SearchActivity">

    <EditText
        android:id="@+id/etQuery"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:hint="@string/query_hint"
        android:ems="10" >

        <requestFocus />
    </EditText>

    <Button
        android:id="@+id/btnSearch"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="onImageSearch"
        android:layout_alignParentRight="true"
        android:layout_alignParentTop="true"
        android:text="@string/search_label" />

    <GridView
        android:id="@+id/gvResults"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/btnSearch"
        android:layout_marginTop="36dp"
        android:numColumns="3" >
    </GridView>

    <Button
        android:id="@+id/advancedSearch"
        style="?android:attr/buttonStyleSmall"
        android:layout_width="wrap_content"
        android:layout_height="18dp"
        android:layout_alignLeft="@+id/etQuery"
        android:layout_below="@+id/btnSearch"
        android:background="#D3F5F4"
        android:text="@string/advanced_search"
        android:textSize="12sp" />

</RelativeLayout>

Answer 1

You have setup all views in onCreate() by setupViews()

public void setupViews() {
    etQuery = (EditText) findViewById(R.id.etQuery);
    gvResults = (GridView) findViewById(R.id.gvResults);
    btnSearch = (Button) findViewById(R.id.btnSearch);  
}

the individual code segment like:

//GridView gvResults = (GridView) findViewById(R.id.gvResults);
    gvResults.setOnScrollListener(new EndlessScrollListener() {

and

//Button advancedSearch = (Button) findViewById(R.id.advancedSearch);
public void setupAdvancedOptionsListener() {

are not necessary. Just delete them.

Edit:

declare Button advancedSearch; as a member variable.

and add advancedSearch = (Button) findViewById(R.id.advancedSearch); in setupViews() method.

Answer 2

I guess line 66 is

Button advancedSearch = (Button) findViewById(R.id.advancedSearch);

You do not have a button with id advancedSearch in activity_search.xml. SO initialization fails leading to NullPointerException.

Edit:

After looking at the source code. It looks like you have the Button initialized outside onCreate. Initialize it inside onCreate and make sure you have the braces } in the right place.

It looks like you have misplaced }.

Get rid of this

setupAdvancedOptionsListener();

and this

public void setupAdvancedOptionsListener() {

Change to

Button advancedSearch = (Button) findViewById(R.id.advancedSearch);
advancedSearch.setOnClickListener(new OnClickListener() {
        public void onClick(View v){
            Intent i = new Intent (MainActivity.this, AdvancedOptionsActivity.class);
            startActivity(i);
        }

    });
 } // brace of onCreate end here.

Edit:

What you could have done. Call this in onCreate

  setupAdvancedOptionsListener();
  } // end of onCreate

Then

  public void setupAdvancedOptionsListener() {
     Button advancedSearch = (Button) findViewById(R.id.advancedSearch);
     advancedSearch.setOnClickListener(new OnClickListener() {
        public void onClick(View v){
            Intent i = new Intent (MainActivity.this, AdvancedOptionsActivity.class);
            startActivity(i);
        }

    });
  }

Answer 3

Try this..

Initilize below Button inside OnCreate

Button advancedSearch;

inside OnCreate

 advancedSearch = (Button) findViewById(R.id.advancedSearch);

 advancedSearch.setOnClickListener(new OnClickListener() {
    public void onClick(View v){
        Intent i = new Intent (MainActivity.this, AdvancedOptionsActivity.class);
        startActivity(i);
    }
});