Why data can't be retrieved from sqlite database in a listview?

I want to display my all data in a listview from the data added by the sqlite database.When I click on the save button,it is shown a message "Added successfully".But each time it is showing error message "Data not found". Why listview is not displayed?

The error is showing as below :

08-28 14:15:22.861 1442-1666/? E/ConnectivityService: RemoteException caught trying to send a callback msg for NetworkRequest [ LISTEN id=89, [ Capabilities: INTERNET&NOT_RESTRICTED&TRUSTED] ]
08-28 14:15:50.753 17164-17164/? E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.user.customadapterwithimage, PID: 17164
android.content.ActivityNotFoundException: No Activity found to handle Intent act=android.intent.action.PICK dat=contents://media/internal/images/media
at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1816)
at android.app.Instrumentation.execStartActivity(Instrumentation.java:1525)
at android.app.Activity.startActivityForResult(Activity.java:4403)
at android.support.v4.app.BaseFragmentActivityApi16.startActivityForResult(BaseFragmentActivityApi16.java:54)
at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:68)
at android.app.Activity.startActivityForResult(Activity.java:4361)
at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:744)
at com.example.user.customadapterwithimage.TraineeListActivity$1.onClick(TraineeListActivity.java:37)
at android.view.View.performClick(View.java:5647)
at android.view.View$PerformClick.run(View.java:22462)
at android.os.Handler.handleCallback(Handler.java:754)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:163)
at android.app.ActivityThread.main(ActivityThread.java:6361)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:904)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:794)

MainActivity.java

package com.example.user.finalprojectsqlite;

import android.Manifest;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.drawable.BitmapDrawable;
import android.net.Uri;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.Toast;

import com.theartofdev.edmodo.cropper.CropImage;
import com.theartofdev.edmodo.cropper.CropImageView;

import java.io.ByteArrayOutputStream;

public class MainActivity extends AppCompatActivity

private static final int REQUEST_CODE_GALLERY=999;
MyDatabaseHelper myDatabaseHelper;

private EditText nameET,ageET,phnET,idET;
private Button saveBT,showBT;
private ImageView newTraineeIV;

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

nameET=findViewById(R.id.nameET);
ageET=findViewById(R.id.ageET);
phnET=findViewById(R.id.phoneET);


saveBT=findViewById(R.id.saveBtn);
showBT=findViewById(R.id.displayBtn);

myDatabaseHelper=new MyDatabaseHelper(this);
myDatabaseHelper.queryData(MyDatabaseHelper.CREATE_TABLE_TRAINEE);


newTraineeIV=findViewById(R.id.add_img);

newTraineeIV.setOnClickListener(new View.OnClickListener()
@Override
public void onClick(View v)

ActivityCompat.requestPermissions(MainActivity.this,
new StringManifest.permission.READ_EXTERNAL_STORAGE,
REQUEST_CODE_GALLERY);


);
saveBT.setOnClickListener(new View.OnClickListener()
@Override
public void onClick(View v)

try
myDatabaseHelper.insertTrainee(
nameET.getText().toString().trim(),
ageET.getText().toString().trim(),
phnET.getText().toString().trim(),
imageViewToByte(newTraineeIV)
);
Toast.makeText(MainActivity.this,"Added successfully",Toast.LENGTH_SHORT).show();
nameET.setText(" ");
ageET.setText(" ");
phnET.setText(" ");
newTraineeIV.setImageResource(R.drawable.add_img);

catch (Exception e)
e.printStackTrace();





);

showBT.setOnClickListener(new View.OnClickListener()
@Override
public void onClick(View v)

Intent traineeIntent=new Intent(MainActivity.this,TraineeListActivity.class);
startActivity(traineeIntent);


);


public static byte imageViewToByte(ImageView image)
Bitmap bitmap=((BitmapDrawable)image.getDrawable()).getBitmap();
ByteArrayOutputStream stream=new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG,100,stream);
byte byteArray=stream.toByteArray();
return byteArray;



@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String permissions, @NonNull int grantResults)

if(requestCode==REQUEST_CODE_GALLERY)
if(grantResults.length>0&&grantResults[0]== PackageManager.PERMISSION_GRANTED)
//gallery insert
Intent galleryIntent=new Intent(Intent.ACTION_GET_CONTENT);
galleryIntent.setType("image/*");
startActivityForResult(galleryIntent,REQUEST_CODE_GALLERY);
else
Toast.makeText(this,"Don't have permission to access file",Toast.LENGTH_SHORT).show();

return;

super.onRequestPermissionsResult(requestCode, permissions, grantResults);

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)

if(requestCode==REQUEST_CODE_GALLERY&&resultCode==RESULT_OK)
Uri imageUri=data.getData();
CropImage.activity(imageUri)
.setGuidelines(CropImageView.Guidelines.ON)
.setAspectRatio(1,1)
.start(this);


if(requestCode==CropImage.CROP_IMAGE_ACTIVITY_REQUEST_CODE)
CropImage.ActivityResult result=CropImage.getActivityResult(data);
if(resultCode==RESULT_OK)
Uri resultUri=result.getUri();
newTraineeIV.setImageURI(resultUri);

else if(resultCode==CropImage.CROP_IMAGE_ACTIVITY_RESULT_ERROR_CODE)
Exception err=result.getError();


super.onActivityResult(requestCode, resultCode, data);




TraineeListActivity.java:

package com.example.user.finalprojectsqlite;

import android.database.Cursor;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.Toast;

import java.util.ArrayList;

public class TraineeListActivity extends AppCompatActivity

ListView mListView;
ArrayList<TraineeModel> mList;
TraineeListAdapter mAdapter = null;
MyDatabaseHelper myDatabaseHelper;

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

myDatabaseHelper = new MyDatabaseHelper(this);

mListView = findViewById(R.id.traineeList);
mList = new ArrayList<>();
mAdapter = new TraineeListAdapter(this, R.layout.trainee_row, mList);
mListView.setAdapter(mAdapter);

//get all data
Cursor cursor = myDatabaseHelper.getData("SELECT * FROM trainee");
mList.clear();
while ((cursor.moveToNext()))
int id = cursor.getInt(0);
String name = cursor.getString(1);
String age = cursor.getString(2);
String phone = cursor.getString(3);
byte image = cursor.getBlob(4);

//add to listrayLis
mList.add(new TraineeModel(id, name, age, phone, image));

mAdapter.notifyDataSetChanged();
if (mList.size() == 0)
//if no record in db
Toast.makeText(TraineeListActivity.this, "No record found!!", Toast.LENGTH_SHORT).show();

mListView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener()
@Override
public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id)
return false;

);




trainee_list_activity.xml:

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
xmlns:app="http://schemas.android.com/apk/res-auto"
app:cardElevation="3dp"
app:cardUseCompatPadding="true"
app:cardBackgroundColor="#71d4c7"
app:contentPadding="5dp">

<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:layout_gravity="center_vertical">

<ImageView
android:id="@+id/traineeIcon"
android:layout_width="100dp"
android:layout_height="100dp"
android:src="@mipmap/ic_launcher_round"/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:layout_marginLeft="5dp">
<TableLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TableRow>
<TextView
android:textStyle="bold"
android:text="Name :"
android:textAllCaps="false"
android:textSize="20sp"
android:layout_height="wrap_content"
android:layout_width="match_parent"

/>
<TextView
android:id="@+id/traineeNameText"
android:textStyle="normal"
android:text="Name here"
android:textAllCaps="false"
android:textSize="20sp"
android:layout_height="wrap_content"
android:layout_width="match_parent"

/>
</TableRow>
<TableRow>
<TextView
android:textStyle="bold"
android:text="Age :"
android:textAllCaps="false"
android:textSize="20sp"
android:layout_height="wrap_content"
android:layout_width="match_parent"

/>
<TextView
android:id="@+id/traineeAgeText"
android:textStyle="normal"
android:text="Age here"
android:textAllCaps="false"
android:textSize="20sp"
android:layout_height="wrap_content"
android:layout_width="match_parent"

/>
</TableRow>
<TableRow>
<TextView
android:textStyle="bold"
android:text="Phone no :"
android:textAllCaps="false"
android:textSize="20sp"
android:layout_height="wrap_content"
android:layout_width="match_parent"

/>
<TextView
android:id="@+id/traineePhnText"
android:textStyle="normal"
android:text="Phone no here"
android:textAllCaps="false"
android:textSize="20sp"
android:layout_height="wrap_content"
android:layout_width="match_parent"

/>
</TableRow>

</TableLayout>

</LinearLayout>

</LinearLayout>

</android.support.v7.widget.CardView>


MyDatabaseHelper.java

package com.example.user.finalprojectsqlite;

import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.database.sqlite.SQLiteStatement;

public class MyDatabaseHelper extends SQLiteOpenHelper

private static final String DATABASE_NAME="Gymnesium";
private static final String TRAINEE_TABLE_NAME="trainee";
private static final int VERSION_NUMBER=1;

static final String CREATE_TABLE_TRAINEE= "CREATE TABLE IF NOT EXISTS "+TRAINEE_TABLE_NAME+"(id INTEGER PRIMARY KEY AUTOINCREMENT, name VARCHAR, age VARCHAR, phone VARCHAR, traineeimg BLOB)";

public MyDatabaseHelper(Context context)
super(context, DATABASE_NAME, null, VERSION_NUMBER);




public void queryData(String sql)
SQLiteDatabase sqLiteDatabase=getWritableDatabase();
sqLiteDatabase.execSQL(sql);

public void insertTrainee(String name,String age,String phone,byte traineeimg)

SQLiteDatabase sqLiteDatabase=getWritableDatabase();
String sql="INSERT INTO trainee VALUES(NULL, ?, ?, ?, ?)";
SQLiteStatement statement=sqLiteDatabase.compileStatement(sql);
statement.clearBindings();

statement.bindString(1,name);
statement.bindString(2,age);
statement.bindString(3,phone);
statement.bindBlob(4,traineeimg);

statement.executeInsert();


public void updateData(String name,String age,String phone,byte traineeimg,int id)

SQLiteDatabase sqLiteDatabase=getWritableDatabase();

String sql="UPDATE trainee SET name=?, age=?, phone=?, traineeimg=? WHERE id=?";
SQLiteStatement statement=sqLiteDatabase.compileStatement(sql);

statement.bindString(1,name);
statement.bindString(2,age);
statement.bindString(3,phone);
statement.bindBlob(4,traineeimg);
statement.bindDouble(5,(double) id);

statement.execute();
sqLiteDatabase.close();


public void deleteTrainee(int id)
SQLiteDatabase sqLiteDatabase=getWritableDatabase();
String sql="DELETE FROM trainee WHERE id=?";

SQLiteStatement statement=sqLiteDatabase.compileStatement(sql);
statement.clearBindings();
statement.bindDouble(1,(double) id);

statement.execute();
sqLiteDatabase.close();


public Cursor getData(String sql)
SQLiteDatabase sqLiteDatabase=getReadableDatabase();
return sqLiteDatabase.rawQuery(sql,null);


@Override
public void onCreate(SQLiteDatabase db)



@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)






TraineeListActivity.java

2 Answers
2

Try this you declare adapter before load data from database so data null try as below.

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

myDatabaseHelper = new MyDatabaseHelper(this);

mListView = findViewById(R.id.traineeList);
mList = new ArrayList<>();


//get all data
Cursor cursor = myDatabaseHelper.getData("SELECT * FROM trainee");
mList.clear();
while ((cursor.moveToNext()))
int id = cursor.getInt(0);
String name = cursor.getString(1);
String age = cursor.getString(2);
String phone = cursor.getString(3);
byte image = cursor.getBlob(4);

//add to listrayLis
mList.add(new TraineeModel(id, name, age, phone, image));

mAdapter = new TraineeListAdapter(this, R.layout.trainee_row, mList);
mListView.setAdapter(mAdapter);
mAdapter.notifyDataSetChanged();
if (mList.size() == 0)
//if no record in db
Toast.makeText(TraineeListActivity.this, "No record found!!", Toast.LENGTH_SHORT).show();

mListView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener()
@Override
public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id)
return false;

);



better move cursor to first record before using it.

if (cursor !=null && cursor.getCount() != 0 && cursor.moveToFirst())
do
int id = cursor.getInt(0);
String name = cursor.getString(1);
String age = cursor.getString(2);
String phone = cursor.getString(3);
byte image = cursor.getBlob(4);

//add to listrayLis
mList.add(new TraineeModel(id, name, age, phone, image));
while (cursor.moveToNext());



if (cursor !=null)
cursor.close();



using cursor.moveToNext() in while loop may course to skip first record.

cursor.moveToNext()

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