Unable to instantiate activity. java.lang.IllegalAccessException: void com.example.myapp.FirstActivity.<init>() is not accessible from java.lang.Class

Question

Whenever i start the app, the apps opens but as soon as i click anyone of the button 1 or button 2 of mainactivity, i get this error :

java.lang.RuntimeException: Unable to instantiate activity 
ComponentInfo{com.example.myapp/com.example.myapp.FirstActivity}: java.lang.IllegalAccessException: 
void com.example.myapp.FirstActivity.<init>() is not accessible from 
java.lang.Class<android.app.AppComponentFactory>
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3341)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3595)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83)
        at 
android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2147)
        at android.os.Handler.dispatchMessage(Handler.java:107)
        at android.os.Looper.loop(Looper.java:237)
        at android.app.ActivityThread.main(ActivityThread.java:7814)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1068)
     Caused by: java.lang.IllegalAccessException: void com.example.myapp.FirstActivity.<init>() is 
not accessible from java.lang.Class<android.app.AppComponentFactory>
        at java.lang.Class.newInstance(Native Method)
        at android.app.AppComponentFactory.instantiateActivity(AppComponentFactory.java:95)
        at androidx.core.app.CoreComponentFactory.instantiateActivity(CoreComponentFactory.java:45)
        at android.app.Instrumentation.newActivity(Instrumentation.java:1251)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3329)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3595) 
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83) 
        at 
android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135) 
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2147) 
        at android.os.Handler.dispatchMessage(Handler.java:107) 
        at android.os.Looper.loop(Looper.java:237) 
        at android.app.ActivityThread.main(ActivityThread.java:7814) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1068)

I am trying to make a tic-tac-toe game with a save feature in which all the data goes to SQLite database and then retrieve the data to play the saved game. Whenever i press any button, the app crashes and the get error mentioned above. I run my app in my own phone android 11.

My code :

MainActivity :

package com.example.myapp;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

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

    Button btn1 = findViewById(R.id.btn1);
    btn1.setOnClickListener(this);
    Button btn2 = findViewById(R.id.btn2);
    btn2.setOnClickListener(this);
    Button btn3 = findViewById(R.id.btn3);
    btn3.setOnClickListener(this);
}

@Override
public void onClick(View view) {
    switch(view.getId()) {
        case R.id.btn1 :
            Intent intent1 = new Intent(this, FirstActivity.class);
            intent1.putExtra("KEY1", "VALUE1");
            startActivity(intent1);
            break;
        case R.id.btn2 :
            Intent intent2 = new Intent(this, SavedgameActivity.class);
            intent2.putExtra("KEY2", "VALUE2");
            startActivity(intent2);
            break;
        case R.id.btn3 :
            break;
    }
}

}

FirstActivity :

package com.example.myapp;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import java.util.ArrayList;

public class FirstActivity extends AppCompatActivity implements View.OnClickListener {

ArrayList<Integer> a = new ArrayList<Integer>(9);
ArrayList<Integer> b = new ArrayList<Integer>(9);
boolean chance = true;
int c=-1,d=-1;
Button btn1, btn2, btn3, btn4, btn5, btn6, btn7, btn8, btn9, btn10, btn11;
TextView txtview4;
TextView txtview5;
int score1 = 0, score2 = 0;
String savename = "";
DBhelper db;

FirstActivity() {

}

public FirstActivity(boolean check, int score1, int score2, boolean chance, int c, int d, String btn) 
{
    this.chance = chance;
    this.score1 = score1;
    this.score2 = score2;
    this.chance = chance;
    this.c = c;
    this.d = d;
    btn1.setText(btn.charAt(0));
    btn2.setText(btn.charAt(1));
    btn3.setText(btn.charAt(2));
    btn4.setText(btn.charAt(3));
    btn5.setText(btn.charAt(4));
    btn6.setText(btn.charAt(5));
    btn7.setText(btn.charAt(6));
    btn8.setText(btn.charAt(7));
    btn9.setText(btn.charAt(8));
}

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_first);
    txtview4 = findViewById(R.id.textView4);
    txtview5 = findViewById(R.id.textView5);
    btn1 = findViewById(R.id.button1);
    btn2 = findViewById(R.id.button2);
    btn3 = findViewById(R.id.button3);
    btn4 = findViewById(R.id.button4);
    btn5 = findViewById(R.id.button5);
    btn6 = findViewById(R.id.button6);
    btn7 = findViewById(R.id.button7);
    btn8 = findViewById(R.id.button8);
    btn9 = findViewById(R.id.button9);
    btn10 = findViewById(R.id.button10);
    btn11 = findViewById(R.id.button11);
    btn1.setOnClickListener(this);
    btn2.setOnClickListener(this);
    btn3.setOnClickListener(this);
    btn4.setOnClickListener(this);
    btn5.setOnClickListener(this);
    btn6.setOnClickListener(this);
    btn7.setOnClickListener(this);
    btn8.setOnClickListener(this);
    btn9.setOnClickListener(this);
    btn10.setOnClickListener(this);
    btn11.setOnClickListener(this);
    
    db = new DBhelper(this);
}

@Override
public void onClick(View view) {
    switch(view.getId()) {
        case R.id.button1 :
            if(chance == true) {
                c = c+1;
                a.add(c, 1);
                btn1.setText("X");
            }
            else {
                d = d+1;
                b.add(d, 1);
                btn1.setText("O");
            }
            break;
        case R.id.button2 :
            if(chance == true) {
                c = c+1;
                a.add(c, 2);
                btn2.setText("X");
            }
            else {
                d = d+1;
                b.add(d, 2);
                btn2.setText("O");
            }
             break;
        case R.id.button3 :
            if(chance == true) {
                c = c+1;
                a.add(c, 3);
                btn3.setText("X");
            }
            else {
                d = d+1;
                b.add(d, 3);
                btn3.setText("O");
            }
            break;
        case R.id.button4 :
            if(chance == true) {
                c = c+1;
                a.add(c, 4);
                btn4.setText("X");
            }
            else {
                d = d+1;
                b.add(d, 4);
                btn4.setText("O");
            }
            break;
        case R.id.button5 :
            if(chance == true) {
                c = c+1;
                a.add(c, 5);
                btn5.setText("X");
            }
            else {
                d = d+1;
                b.add(d, 5);
                btn5.setText("O");
            }
            break;
        case R.id.button6 :
            if(chance == true) {
                c = c+1;
                a.add(c, 6);
                btn6.setText("X");
            }
            else {
                d = d+1;
                b.add(d, 6);
                btn6.setText("O");
            }
            break;
        case R.id.button7 :
            if(chance == true) {
                c = c+1;
                a.add(c, 7);
                btn7.setText("X");
            }
            else {
                d = d+1;
                b.add(d, 7);
                btn7.setText("O");
            }
            break;
        case R.id.button8 :
            if(chance == true) {
                c = c+1;
            a.add(c, 8);
            btn8.setText("X");
        }
            else {
                d = d+1;
            b.add(d, 8);
            btn8.setText("O");
        }
        break;
        case R.id.button9 :
            if(chance == true) {
                c = c+1;
                a.add(c, 9);
                btn9.setText("X");
            }
            else {
                d = d+1;
                b.add(d, 9);
                btn9.setText("O");
            }
            break;
        case R.id.button10 :
            String btn = btn1.getText().toString() + btn2.getText().toString() + 
btn3.getText().toString() + btn4.getText().toString() + btn5.getText().toString() + 
btn6.getText().toString() + btn7.getText().toString() + btn8.getText().toString() + 
btn9.getText().toString();

            SavedgameActivity sga = new SavedgameActivity(false, score1, score2, chance, c, d, btn);

            Intent intent = new Intent(FirstActivity.this, SavedgameActivity.class);
            intent.putExtra("KEY3", "VALUE3");
            startActivity(intent);

            break;
        case R.id.button11 :
            finish();
            break;
    }

    if(chance == true)
         chance = false;
    else
        chance = true;

    if((a.contains(1) && a.contains(2) && a.contains(3))||(a.contains(4) && a.contains(5) && 
a.contains(6))||((a.contains(7) && a.contains(8) && a.contains(9)))||(a.contains(1) && a.contains(4) 
&& a.contains(7))||(a.contains(2) && a.contains(5) && a.contains(8))||(a.contains(3) && a.contains(6) 
&& a.contains(9))||(a.contains(1) && a.contains(5) && a.contains(9))||(a.contains(3) && a.contains(5) 
&& a.contains(7))) {
        score1++;
        txtview4.setText("" + score1);
        btn1.setText("");
        btn2.setText("");
        btn3.setText("");
        btn4.setText("");
        btn5.setText("");
        btn6.setText("");
        btn7.setText("");
        btn8.setText("");
        btn9.setText("");
        c = -1;
        d = -1;
        a.clear();
        b.clear();
        if((score1 + score2)%2 == 0)
            chance = true;
        else
            chance = false;
    }
    else if((b.contains(1) && b.contains(2) && b.contains(3))||(b.contains(4) && b.contains(5) && 
b.contains(6))||((b.contains(7) && b.contains(8) && b.contains(9)))||(b.contains(1) && b.contains(4) 
&& b.contains(7))||(b.contains(2) && b.contains(5) && b.contains(8))||(b.contains(3) && b.contains(6) 
&& b.contains(9))||(b.contains(1) && b.contains(5) && b.contains(9))||(b.contains(3) && b.contains(5) 
&& b.contains(7))) {
        score2++;
        txtview5.setText("" + score2);
        btn1.setText("");
        btn2.setText("");
        btn3.setText("");
        btn4.setText("");
        btn5.setText("");
        btn6.setText("");
        btn7.setText("");
        btn8.setText("");
        btn9.setText("");
        c = -1;
        d = -1;
        a.clear();
        b.clear();
        if ((score1 + score2) % 2 == 0)
            chance = true;
        else
            chance = false;
    }
}

}

SavedGameActivity :

package com.example.myapp;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import java.util.ArrayList;

public class SavedgameActivity extends AppCompatActivity {
boolean check = true;
int score1;
int score2;
boolean chance, dialogcheck, isupdated, isinserted;
int c;
int d;
String btn;
DBhelper db = new DBhelper(this);

TextView txt6, txt7, txt8;
Button btn12, btn13, btn14;

SavedgameActivity() {

}

public SavedgameActivity(boolean check, int score1, int score2, boolean chance, int c, int d, String 
btn) {
    this.check = check;
    this.score1 = score1;
    this.score2 = score2;
    this.chance = chance;
    this.c = c;
    this.d = d;
    this.btn = btn;
}

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

    if(check == false) {
        falsemethod();
    }
    else
        truemethod();
}

public void falsemethod() {
    btn12 = findViewById(R.id.button12);
    btn13 = findViewById(R.id.button13);
    btn14 = findViewById(R.id.button14);
    txt6 = findViewById(R.id.textView6);
    txt7 = findViewById(R.id.textView7);
    txt8 = findViewById(R.id.textView8);
    Cursor savegame1 =  db.getgame(txt6.getText().toString());
    Cursor savegame2 =  db.getgame(txt7.getText().toString());
    Cursor savegame3 =  db.getgame(txt8.getText().toString());

    ArrayList<String> itemIds1 = new ArrayList<String>();
    while(savegame1.moveToNext()) {
        itemIds1.add(savegame1.getString(savegame1.getColumnIndex("id")));
    }
    savegame1.close();

    ArrayList<String> itemIds2 = new ArrayList<String>();
    while(savegame2.moveToNext()) {
        itemIds2.add(savegame2.getString(savegame2.getColumnIndex("id")));
    }
    savegame2.close();

    ArrayList<String> itemIds3 = new ArrayList<String>();
    while(savegame3.moveToNext()) {
        itemIds3.add(savegame3.getString(savegame3.getColumnIndex("id")));
    }
    savegame3.close();

    if(Integer.parseInt(itemIds1.get(0)) < 1)
        btn12.setText("Save");
    else
        btn12.setText("Override and Save");
    if(Integer.parseInt(itemIds2.get(0)) < 1)
        btn12.setText("Save");
    else
        btn12.setText("Override and Save");
    if(Integer.parseInt(itemIds2.get(0)) < 1)
        btn12.setText("Save");
    else
        btn12.setText("Override and Save");

    btn12.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            if(Integer.parseInt(itemIds1.get(0)) < 1)
                isinserted = db.addgame(score1, score2, chance, c, d, btn);
            else
                isupdated = db.updategame(score1, score2, chance, c, d, btn, 
btn12.getText().toString());
        }
    });
    btn13.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            if(Integer.parseInt(itemIds2.get(0)) < 1)
                isinserted = db.addgame(score1, score2, chance, c, d, btn);
            else
                isupdated = db.updategame(score1, score2, chance, c, d, btn, 
btn13.getText().toString());
        }
    });
    btn14.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            if(Integer.parseInt(itemIds3.get(0)) < 1)
                isinserted = db.addgame(score1, score2, chance, c, d, btn);
            else
                isupdated = db.updategame(score1, score2, chance, c, d, btn, 
btn14.getText().toString());
        }
    });

    if((isinserted == true) || (isupdated == true))
        Toast.makeText(SavedgameActivity.this, "Game Saved", Toast.LENGTH_LONG).show();
    else
        Toast.makeText(SavedgameActivity.this, "Game Not Saved", Toast.LENGTH_LONG).show();

}

public void truemethod() {
    btn12.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Cursor Getgame = db.getgame(txt6.getText().toString());
            ArrayList<Long> itemIds = new ArrayList<Long>();
            while(Getgame.moveToNext()) {
                long itemId = Getgame.getLong(
                        Getgame.getColumnIndexOrThrow("id"));
                itemIds.add(itemId);
            }
            Getgame.close();
            if (itemIds.get(0) < 1)
                Toast.makeText(SavedgameActivity.this, "Game not saved yet", Toast.LENGTH_LONG).show();
            else {
                FirstActivity fa = new FirstActivity(check, score1, score2, chance, c, d, btn);

                Intent intent = new Intent();
                intent.putExtra("KEY4", "VALUE4");
                startActivity(intent);
            }
        }
    });
}

public void setCheck(boolean check) {
    this.check = check;
}

}

DBhelper class :

package com.example.myapp;

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

import androidx.annotation.Nullable;

public class DBhelper extends SQLiteOpenHelper {

SQLiteDatabase db = this.getWritableDatabase();
SQLiteDatabase db1 = this.getReadableDatabase();

public DBhelper(@Nullable Context context) {
    super(context, "Database", null, 1);
    SQLiteDatabase database = this.getWritableDatabase();
}

@Override
public void onCreate(SQLiteDatabase db) {
    db.execSQL("CREATE TABLE Save(id INTEGER PRIMARY KEY AUTOINCREMENT, score1 INTEGER, score2 
INTEGER, chance BOOLEAN, c INTEGER, d INTEGER, btn TEXT)");
}

@Override
public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {

}

public boolean addgame(int Score1, int Score2, boolean Chance, int C, int D, String Btn) {
    SQLiteDatabase db = this.getWritableDatabase();

    ContentValues cv = new ContentValues();
    cv.put("score1", Score1);
    cv.put("score2", Score2);
    cv.put("chance", Chance);
    cv.put("c", C);
    cv.put("d", D);
    cv.put("btn", Btn);

    long result = db.insert("Save", null, cv);

    if(result == -1)
        return false;
    else
        return true;
}

public Cursor getgame(String a) {
    Cursor res = db.query("Save", null, "id = ?", new String[]{a}, null, null, "btn DESC");
    return res;
}

public boolean updategame(int Score1, int Score2, boolean Chance, int C, int D, String Btn, String 
id) {
    int nameid = Integer.parseInt(id);

    ContentValues cv = new ContentValues();
    cv.put("id", nameid);
    cv.put("score1", Score1);
    cv.put("score2", Score2);
    cv.put("chance", Chance);
    cv.put("c", C);
    cv.put("d", D);
    cv.put("btn", Btn);

    long result =  db1.update("Save", cv, "id = ?", new String[]{id});

    if(result == -1)
        return false;
    else
        return true;
}

public void closedb() {
    db.close();
}
}

Mainfest file :

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.myapp">
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.MyApp">
        <activity android:name=".SavedgameActivity" />
        <activity android:name=".FirstActivity" />
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest>

Please give me a solution. Thanks.

Answer 1

It seems to me that you are trying to instantiate activity using a custom constructor, which is not possible in Android. Try to remove constructors for your FirstActivity and SavedgameActivity. If you need to pass some data to the activities, you should pass them as a part of the intent starting the activity. Simply remove public FirstActivity(boolean check, int score1, int score2, boolean chance, int c, int d, String btn) and public SavedgameActivity(boolean check, int score1, int score2, boolean chance, int c, int d, String btn) and try again.

Answer 2

Your Activity empty constructor is protected. hence it's not accessible. You should never make your activity empty constructor non-public.

And to pass variables that you want to pass to an Activity you can pass them in Intent as extras, which you can extract in onCreate() of your activity.

Answer 3

There's no visibility modifier for the default constructor in the FirstActivity class. When you do not specify a visibility modifier, the field or the method won't be accessible from the outside of the package. Android is trying to create that class with the empty constructor, but it can't, because it's not in the same package as your class. You should set it as public like this:

public FirstActivity() {

}

The same thing goes with SavedGameActivity class, otherwise, you'll have the same problem in the future.