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An Error occurs when I was making a code to create a show list by ListView{in content_main.xml} like contact view

I was making a code to create a show list by ListView{in content_main.xml} like contact view.
I build a database in the (SQLite Expert Professional) with a table(name: "contact") that was contained a few name and family and numbers, with ID,NAME,fAMILY and PHONE NUMBER columns.
ID was unique, auto increment and primary key...other were Text except number that was CHAR.
then I calling them to my ListView as you see in below.(before it I made a row_list activity to made my listview , custom) but there was an Error and I can't find it.
{I could find my database.db file with that's table in the source data files that means my mistake wasn't from creating database.}
plz help me.I wanna learn android (as fast as i can) to get a JOB and I need it..
Errors.Android Monitor.Logcat
09-08 05:27:32.005 5692-5692/? W/dalvikvm: threadid=1: thread exiting with uncaught exception (group=0x94c4fb20)
09-08 05:27:32.005 5692-5692/? E/AndroidRuntime: FATAL EXCEPTION: main
Process: mizco.phonebook, PID: 5692
java.lang.RuntimeException: Unable to start activity ComponentInfo{mizco.phonebook/mizco.phonebook.Main}: android.database
.CursorIndexOutOfBoundsException: Index 5 requested, with a size of 5
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2193)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2243)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5019)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)
Caused by: android.database.CursorIndexOutOfBoundsException: Index 5 requested, with a size of 5
at android.database.AbstractCursor.checkPosition(AbstractCursor.java:426)
at android.database.AbstractWindowedCursor.checkPosition(AbstractWindowedCursor.java:136)
at android.database.AbstractWindowedCursor.getString(AbstractWindowedCursor.java:50)
at mizco.phonebook.database.getfulllist(database.java:97)
at mizco.phonebook.Main.onCreate(Main.java:36)
at android.app.Activity.performCreate(Activity.java:5231)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1104)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2157)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2243)
at android.app.ActivityThread.access$800(ActivityThread.java:135)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5019)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)
Main.java
package mizco.phonebook;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.design.widget.FloatingActionButton;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
public class Main extends AppCompatActivity {
private database db;
private String [][] res ;
private ListView list;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
list = (ListView) findViewById(R.id.main_list);
db = new database(this);
db.startusing();
db.open();
res = db.getfulllist();
db.close();
list.setAdapter(new AA());
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
}
});
}
class AA extends ArrayAdapter<String>{
public AA() {
super(Main.this, R.layout.row_list, res[0]);
}
#NonNull
#Override
public View getView(final int position, View convertView, ViewGroup parent) {
LayoutInflater in = getLayoutInflater();
View row = in.inflate(R.layout.row_list,parent,false);
TextView name = (TextView) row.findViewById(R.id.row_name);
TextView number = (TextView) row.findViewById(R.id.row_number);
name.setText(res[0][position]+" "+res[1][position]);
number.setText(res[2][position]);
return row;
}
}
}
Class : database.java
package mizco.phonebook;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
/**
* Created by Mahdi on 9/2/2017.
*/
public class database extends SQLiteOpenHelper {
public static String dbname= "database";
public static String dbpath="";
private Context mctxt;
private SQLiteDatabase mydb;
public database(Context context) {
super(context, dbname, null, 1);
mctxt = context;
}
#Override
public void onCreate(SQLiteDatabase db) {
}
#Override
public void onUpgrade(SQLiteDatabase db, int i, int i1) {
}
private boolean existdatabase(){
File m312 = new File(dbpath+dbname);
return m312.exists();
}
private void copydatabase(){
try {
InputStream IS = mctxt.getAssets().open(dbname);
OutputStream OS = new FileOutputStream(dbpath+dbname);
byte[] buffer = new byte[1024];
int length;
while ((length = IS.read(buffer))>0){
OS.write(buffer,0,length);
}
OS.flush();
OS.close();
IS.close();
} catch (Exception e) {
}
}
public void open(){
mydb = SQLiteDatabase.openDatabase(dbpath+dbname, null, SQLiteDatabase.OPEN_READWRITE);
}
public void close(){
mydb.close();
}
public void startusing () {
dbpath = mctxt.getFilesDir().getParent() + "/databases/";
if (!existdatabase()) {
this.getWritableDatabase();
copydatabase();
}
}
public String[][] getfulllist(){
Cursor cu = mydb.rawQuery("select * from Contact",null);
String [][] r = new String[3][cu.getCount()];
for (int i= 0;i<=cu.getCount();i++){
cu.moveToPosition(i);
r[0][i]=cu.getString(1);
r[1][i]=cu.getString(2);
r[2][i]=cu.getString(3);
}
return r;
}
}

You're stepping off the end of the cursor. Your code should read
for (int i= 0;i < cu.getCount();i++){
cu.moveToPosition(i);
r[0][i]=cu.getString(1);
r[1][i]=cu.getString(2);
r[2][i]=cu.getString(3);
}
return r;

Check File Extension in android

i made a small method to check whether defined folder has files with a specific extension or not. I m getting null point exception on run.pls help to find mistake.method is checking .mp4 files and returning true if found and message is displayed.
Here is Code:
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;
import java.io.File;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
TextView filecheck;
filecheck = (TextView) findViewById(R.id.filecheck);
filecheck.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (accept()) {
Toast.makeText(MainActivity.this, "Files Found", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(MainActivity.this, "Files Not Found", Toast.LENGTH_SHORT).show();
}
}
});
}
public boolean accept() {
final File pathname = new File("/sdcard/test/");
String files[] = pathname.list();
System.out.println(files.length);
for (String s : files) {
if (s.contains(".mp4")) {
System.out.println(s);
return true;
}
return false;
}
return false;
}
}
Here is exception:
E/AndroidRuntime: FATAL EXCEPTION: main
Process: jss.testmethods, PID: 23659
java.lang.NullPointerException
at jss.testmethods.MainActivity.accept(MainActivity.java:38)
at jss.testmethods.MainActivity$1.onClick(MainActivity.java:24)
at android.view.View.performClick(View.java:4478)
at android.view.View$PerformClick.run(View.java:18698)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:149)
at android.app.ActivityThread.main(ActivityThread.java:5257)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:609)
at dalvik.system.NativeStart.main(Native Method)

i was expecting simple error, i missed to add permission for read storage. it is working now.

Missing file through getAssets

I have a problem connected with reading a file in Java Application. Please help me as I'm trying to do it for four days and my CS teacher is not into Android Apps. Also any of the tutorials read does not help me.
I have a following app:
package com.bachosz.billionaires;
import android.support.v7.app.ActionBarActivity;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;
import java.util.StringTokenizer;
import android.content.ContextWrapper;
import android.content.res.AssetFileDescriptor;
import android.content.res.AssetManager;
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.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivityBillionaires extends ActionBarActivity {
private int currentQuestion;
private String [] answers;
private Button answerButton;
private Button questionButton;
private TextView questionView;
private TextView answerView;
private EditText answerText;
private Question [] questions;
private Button buttonA;
private Button buttonB;
private Button buttonC;
private Button buttonD;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main_activity_billionaires);
try {
init();
} catch (IOException e) {
e.printStackTrace();
}
}
public void init() throws IOException
{
questions = new Question[2];
currentQuestion = 0;
InputStream inputStream = getResources().openRawResource(R.raw.questionstable);
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
String line = null;
String content,a,b,c,d,correct;
int id, x = 0;
StringTokenizer st = null;
while ((line=reader.readLine()) != null)
{
st= new StringTokenizer(line, ",");
id = Integer.parseInt(st.nextToken());
content = st.nextToken();
a = st.nextToken();
b = st.nextToken();
c = st.nextToken();
d = st.nextToken();
correct = st.nextToken();
questions[x] = new Question(id, content, a, b, c, d, correct);
x++;
}
reader.close();
answerButton = (Button)findViewById(R.id.AnswerButton);
questionButton = (Button)findViewById(R.id.QuestionButton);
questionView = (TextView)findViewById(R.id.QuestionTextView);
answerView = (TextView) findViewById(R.id.AnswerTextView);
answerText = (EditText) findViewById(R.id.AnswerText);
buttonA = (Button)findViewById(R.id.buttonA);
buttonB = (Button)findViewById(R.id.buttonB);
buttonC = (Button)findViewById(R.id.buttonC);
buttonD = (Button)findViewById(R.id.buttonD);
answerButton.setOnClickListener(new OnClickListener()
{
public void onClick(View v) {
checkAnswer();
}});
questionButton.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v) {
showQuestion();
}});
}
public void showQuestion()
{
// if(currentQuestion == questions.length)
// currentQuestion =0;
questionView.setText(questions[0].toString());
answerView.setText("");
answerText.setText("");
currentQuestion++;
}
public boolean isCorrect(String answer)
{
return (answer.equalsIgnoreCase(questions[currentQuestion].getCorrect()));
}
public void checkRight()
{
// String right
}
public void checkAnswer()
{
String answer = questions[currentQuestion].getCorrect();
if(isCorrect(answer))
answerView.setText("You're right!");
else
answerView.setText("Sorry, the correct answer is "+answers[currentQuestion]);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main_activity_billionaires, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
It is taken from Java application I was writing previously (that is why so many comments). How I can access the fileName in Android App? I was trying InputStream, get Assets, etc. but It does not work or I am doing it improperly. Currently it is throwing NullPointerException.
LOG CAT:
10-09 13:38:37.663: E/Trace(921): error opening trace file: No such file or directory (2)
10-09 13:38:39.354: D/AndroidRuntime(921): Shutting down VM
10-09 13:38:39.354: W/dalvikvm(921): threadid=1: thread exiting with uncaught exception (group=0x40a13300)
10-09 13:38:39.384: E/AndroidRuntime(921): FATAL EXCEPTION: main
10-09 13:38:39.384: E/AndroidRuntime(921): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.bachosz.billionaires/com.bachosz.billionaires.MainActivityBillionaires}: java.lang.NullPointerException
10-09 13:38:39.384: E/AndroidRuntime(921): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059)
10-09 13:38:39.384: E/AndroidRuntime(921): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
10-09 13:38:39.384: E/AndroidRuntime(921): at android.app.ActivityThread.access$600(ActivityThread.java:130)
10-09 13:38:39.384: E/AndroidRuntime(921): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
10-09 13:38:39.384: E/AndroidRuntime(921): at android.os.Handler.dispatchMessage(Handler.java:99)
10-09 13:38:39.384: E/AndroidRuntime(921): at android.os.Looper.loop(Looper.java:137)
10-09 13:38:39.384: E/AndroidRuntime(921): at android.app.ActivityThread.main(ActivityThread.java:4745)
10-09 13:38:39.384: E/AndroidRuntime(921): at java.lang.reflect.Method.invokeNative(Native Method)
10-09 13:38:39.384: E/AndroidRuntime(921): at java.lang.reflect.Method.invoke(Method.java:511)
10-09 13:38:39.384: E/AndroidRuntime(921): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
10-09 13:38:39.384: E/AndroidRuntime(921): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
10-09 13:38:39.384: E/AndroidRuntime(921): at dalvik.system.NativeStart.main(Native Method)
10-09 13:38:39.384: E/AndroidRuntime(921): Caused by: java.lang.NullPointerException
10-09 13:38:39.384: E/AndroidRuntime(921): at com.bachosz.billionaires.MainActivityBillionaires.readFile(MainActivityBillionaires.java:111)
10-09 13:38:39.384: E/AndroidRuntime(921): at com.bachosz.billionaires.MainActivityBillionaires.init(MainActivityBillionaires.java:140)
10-09 13:38:39.384: E/AndroidRuntime(921): at com.bachosz.billionaires.MainActivityBillionaires.onCreate(MainActivityBillionaires.java:70)
10-09 13:38:39.384: E/AndroidRuntime(921): at android.app.Activity.performCreate(Activity.java:5008)
10-09 13:38:39.384: E/AndroidRuntime(921): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
10-09 13:38:39.384: E/AndroidRuntime(921): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
10-09 13:38:39.384: E/AndroidRuntime(921): ... 11 more

The error says you're getting a NPE (Null Pointer Exception) at com.bachosz.billionaires.MainActivityBillionaires. You need to look at the code section that you use to call that activity. (it is not in your code above - or else we don't know which line with the given information)
Another thing you have to make sure is that you have the appropriate context.
AssetManager assetManage = appContext.getAssets();
String[] filelist = assetManage.list("");

First you should clean up your code, at least to show it here where we don't know what are you doing.
It's easier to understand.
Why are you using assets? In Android the most common way to access resources is the .../res/raw folder.
It makes a reference of the file in the autogenerated R.class so you can access it anywhere.
Make sure your filename is lowercase and has no spaces. If you haven't raw folder under res, create it manually.
Try this:
InputStream inputStream = getResources().openRawResource(R.raw.YOURFILE);
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
String line = reader.readLine();
while (line != null)
{
// Read file.
}

Firstly: copy YOURFILE to assets folder.
Then, AssetManager assetManage = getAssets();
Then,
InputStream myInput = null;
try {
myInput = assetManager.open("YOURFILE");
} catch (IOException e1) {
e1.printStackTrace();
}
And finally BufferedReader reader = new BufferedReader(new InputStreamReader(myInput));
follow the above code step by step.

android: trying to add counter information to sqlite database

I'm made a counter app and I want to add a save function where it saves the current number of the counter into the database. But when I try to run it, its closes unexpectedly.
The logcat and code is below
package com.example.testdatabase;
import android.app.Activity;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class MainActivity extends Activity {
int counter;
Button add;
Button sub;
Button save;
TextView display;
private SharedPreferences prefs;
private String prefName = "MyPref";
MySQLiteHelper db = new MySQLiteHelper(this);
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
counter = 0;
add = (Button) findViewById(R.id.button1);
sub = (Button) findViewById(R.id.button2);
display = (TextView) findViewById(R.id.tvDisplay);
add.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
counter++;
display.setText("Counter: " + counter);
}
});
sub.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
counter--;
display.setText("Counter: " + counter);
}
});
save.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
db.add(counter);
}
});
}
protected void onPause()
{
super.onPause();
prefs = getSharedPreferences(prefName, MODE_PRIVATE);
SharedPreferences.Editor edit = prefs.edit();
edit.putInt("counter", counter);
edit.commit();
}
protected void onResume()
{
super.onResume();
prefs = getSharedPreferences(prefName, MODE_PRIVATE);
counter = prefs.getInt("counter", counter);
display.setText("Counter: " + counter);
}
}
the class the handles the database stuff
package com.example.testdatabase;
import android.content.ContentValues;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
public class MySQLiteHelper extends SQLiteOpenHelper {
// Database Version
private static final int DATABASE_VERSION = 1;
// Database Name
private static final String DATABASE_NAME = "CountDB";
public MySQLiteHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
#Override
public void onCreate(SQLiteDatabase db) {
// SQL statement to create counter table
String CREATE_COUNT_TABLE = "CREATE TABLE count ( " +
"id INTEGER PRIMARY KEY AUTOINCREMENT, " +
"amount INT )";
// create books table
db.execSQL(CREATE_COUNT_TABLE);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// Drop older counter table if existed
db.execSQL("DROP TABLE IF EXISTS count");
// create fresh count table
this.onCreate(db);
}
// Books table name
private static final String TABLE_COUNTER= "count";
// Books Table Columns names
private static final String KEY_ID = "id";
private static final String KEY_AMOUNT = "amount";
private static final String[] COLUMNS = {KEY_ID,KEY_AMOUNT};
public void add(int counter){
// 1. get reference to writable DB
SQLiteDatabase db = this.getWritableDatabase();
// 2. create ContentValues to add key "column"/value
ContentValues values = new ContentValues();
values.put(KEY_AMOUNT, counter); // get counter amount
// 3. insert
db.insert(TABLE_COUNTER, // table
null, //nullColumnHack
values); // key/value -> keys = column names/ values = column values
// 4. close
db.close();
}
the logcat
15:08:30.713: D/AndroidRuntime(302): Shutting down VM
11-17 15:08:30.713: W/dalvikvm(302): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
11-17 15:08:30.742: E/AndroidRuntime(302): FATAL EXCEPTION: main
11-17 15:08:30.742: E/AndroidRuntime(302): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.testdatabase/com.example.testdatabase.MainActivity}: java.lang.NullPointerException
11-17 15:08:30.742: E/AndroidRuntime(302): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
11-17 15:08:30.742: E/AndroidRuntime(302): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
11-17 15:08:30.742: E/AndroidRuntime(302): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
11-17 15:08:30.742: E/AndroidRuntime(302): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
11-17 15:08:30.742: E/AndroidRuntime(302): at android.os.Handler.dispatchMessage(Handler.java:99)
11-17 15:08:30.742: E/AndroidRuntime(302): at android.os.Looper.loop(Looper.java:123)
11-17 15:08:30.742: E/AndroidRuntime(302): at android.app.ActivityThread.main(ActivityThread.java:4627)
11-17 15:08:30.742: E/AndroidRuntime(302): at java.lang.reflect.Method.invokeNative(Native Method)
11-17 15:08:30.742: E/AndroidRuntime(302): at java.lang.reflect.Method.invoke(Method.java:521)
11-17 15:08:30.742: E/AndroidRuntime(302): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
11-17 15:08:30.742: E/AndroidRuntime(302): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
11-17 15:08:30.742: E/AndroidRuntime(302): at dalvik.system.NativeStart.main(Native Method)
11-17 15:08:30.742: E/AndroidRuntime(302): Caused by: java.lang.NullPointerException
11-17 15:08:30.742: E/AndroidRuntime(302): at com.example.testdatabase.MainActivity.onCreate(MainActivity.java:49)
11-17 15:08:30.742: E/AndroidRuntime(302): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
11-17 15:08:30.742: E/AndroidRuntime(302): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
11-17 15:08:30.742: E/AndroidRuntime(302): ... 11 more
any ideas?

Program throws an exception in :
save.setOnClickListener(new View.OnClickListener() ...
It seems that Button save is not initialized.

Cannot Resolve NullPointerException On Service Class

I have been tasked to resolve an issue for a group project at my university however I cannot seem to resolve an issue with a NullPointerException in my service class. Our goal is to create a script which continually monitors the android history until it finds a match - then executes a warning class if the service class finds a match in the browser history. The issue occurs on line 71 (of service class) however I do not know how to resolve the issue.
Service Class:
public class Service_class extends Service {
String Dirty1 = "www.pornhub.com";
String Dirty2 = "www.playboy.com";
String Dirty3 = "www.playboy.com";
String Dirty4 = "www.playboy.com";
String Dirty5 = "www.playboy.com";
String Dirty6 = "www.playboy.com";
String Dirty7 = "www.playboy.com";
String Dirty8 = "www.playboy.com";
String Dirty9 = "www.playboy.com";
String Dirty10 = "www.playboy.com";
#Override
public IBinder onBind(Intent arg0) {
return null;
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Toast.makeText(this, "Service Started", Toast.LENGTH_LONG).show();
return START_STICKY;
}
#Override
public void onDestroy() {
super.onDestroy();
Toast.makeText(this, "Service Stopped", Toast.LENGTH_LONG).show();
}
#Override
public void onCreate() {
super.onCreate();
TextView tv = (TextView) findViewById(R.id.hello);
String[] projection = new String[] { Browser.BookmarkColumns.TITLE,
Browser.BookmarkColumns.URL };
Cursor cursor = managedQuery(android.provider.Browser.BOOKMARKS_URI,
projection, null, null, null);
String urls = "";
if (cursor.moveToFirst()) {
String url1 = null;
String url2 = null;
do {
String url = cursor.getString(cursor.getColumnIndex(Browser.BookmarkColumns.URL));
if (url.toLowerCase().contains(Dirty1)) {
} else if (url.toLowerCase().contains(Dirty2)) {
} else if (url.toLowerCase().contains(Dirty3)) {
} else if (url.toLowerCase().contains(Dirty4)) {
} else if (url.toLowerCase().contains(Dirty5)) {
} else if (url.toLowerCase().contains(Dirty6)) {
} else if (url.toLowerCase().contains(Dirty7)) {
} else if (url.toLowerCase().contains(Dirty8)) {
} else if (url.toLowerCase().contains(Dirty9)) {
} else if (url.toLowerCase().contains(Dirty10)) {
//if (url.toLowerCase().contains(Filthy)) {
urls = urls
+ cursor.getString(cursor.getColumnIndex(Browser.BookmarkColumns.TITLE)) + " : "
+ url + "\n";
Intent intent = new Intent(Service_class.this, Warning.class);
Service_class.this.startActivity(intent);
}
} while (cursor.moveToNext());
// tv.setText(urls);
}
}
private void setContentView(int main3) {
// TODO Auto-generated method stub
}
private TextView findViewById(int hello) {
// TODO Auto-generated method stub
return null;
}
private Cursor managedQuery(Uri bookmarksUri, String[] projection,
Object object, Object object2, Object object3) {
// TODO Auto-generated method stub
return null;
}}
Main.java
import java.util.Calendar;
import com.parse.ParseAnalytics;
import com.parse.ParseObject;
import android.app.Activity;
import android.app.AlarmManager;
import android.app.AlertDialog;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.net.TrafficStats;
import android.net.wifi.WifiInfo;
import android.net.wifi.WifiManager;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.Chronometer;
import android.widget.TextView;
public class Main extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main3);
// Start service using AlarmManager
Calendar cal = Calendar.getInstance();
cal.add(Calendar.SECOND, 10);
Intent intent = new Intent(Main.this, Service_class.class);
PendingIntent pintent = PendingIntent.getService(Main.this, 0, intent,
0);
AlarmManager alarm = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
alarm.setRepeating(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(),
36000 * 1000, pintent);
// click listener for the button to start service
Button btnStart = (Button) findViewById(R.id.button1);
btnStart.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
startService(new Intent(getBaseContext(), Service_class.class));
}
});
// click listener for the button to stop service
Button btnStop = (Button) findViewById(R.id.button2);
btnStop.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
stopService(new Intent(getBaseContext(), Service_class.class));
}
});
}}
LOGCAT:
04-15 13:58:49.980: D/AndroidRuntime(1994): Shutting down VM
04-15 13:58:50.000: W/dalvikvm(1994): threadid=1: thread exiting with uncaught exception (group=0x40cc7930)
04-15 13:58:50.000: E/AndroidRuntime(1994): FATAL EXCEPTION: main
04-15 13:58:50.000: E/AndroidRuntime(1994): java.lang.RuntimeException: Unable to create service com.nfc.linked.Service_class: java.lang.NullPointerException
04-15 13:58:50.000: E/AndroidRuntime(1994): at android.app.ActivityThread.handleCreateService(ActivityThread.java:2539)
04-15 13:58:50.000: E/AndroidRuntime(1994): at android.app.ActivityThread.access$1600(ActivityThread.java:141)
04-15 13:58:50.000: E/AndroidRuntime(1994): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1316)
04-15 13:58:50.000: E/AndroidRuntime(1994): at android.os.Handler.dispatchMessage(Handler.java:99)
04-15 13:58:50.000: E/AndroidRuntime(1994): at android.os.Looper.loop(Looper.java:137)
04-15 13:58:50.000: E/AndroidRuntime(1994): at android.app.ActivityThread.main(ActivityThread.java:5041)
04-15 13:58:50.000: E/AndroidRuntime(1994): at java.lang.reflect.Method.invokeNative(Native Method)
04-15 13:58:50.000: E/AndroidRuntime(1994): at java.lang.reflect.Method.invoke(Method.java:511)
04-15 13:58:50.000: E/AndroidRuntime(1994): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
04-15 13:58:50.000: E/AndroidRuntime(1994): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
04-15 13:58:50.000: E/AndroidRuntime(1994): at dalvik.system.NativeStart.main(Native Method)
04-15 13:58:50.000: E/AndroidRuntime(1994): Caused by: java.lang.NullPointerException
04-15 13:58:50.000: E/AndroidRuntime(1994): at com.nfc.linked.Service_class.onCreate(Service_class.java:71)
04-15 13:58:50.000: E/AndroidRuntime(1994): at android.app.ActivityThread.handleCreateService(ActivityThread.java:2529)
04-15 13:58:50.000: E/AndroidRuntime(1994): ... 10 more
04-15 14:00:23.770: D/AndroidRuntime(2047): Shutting down VM
04-15 14:00:23.770: W/dalvikvm(2047): threadid=1: thread exiting with uncaught exception (group=0x40cc7930)

Your method managedQuery() returns null
private Cursor managedQuery(Uri bookmarksUri, String[] projection,
Object object, Object object2, Object object3) {
// TODO Auto-generated method stub
return null;
}}
So when you try to execute a method on null you will get a NullPointerException.
Cursor cursor = managedQuery(android.provider.Browser.BOOKMARKS_URI,
projection, null, null, null); // cursor will be null
String urls = "";
if (cursor.moveToFirst()) { // this will be NPE
Make your managedQuery() method return an instantiated Cursor object.