Main_Activity Launch crashes

Question

I'm trying to make an android app, but on launching the main activity on an developer device the logcat goes like this:

The device is Samsung GT-S5282: Rooted: Resurrection Remix (Marshmallow)

    07-23 21:35:35.840 28372-28372/? I/art: Late-enabling -Xcheck:jni
07-23 21:35:36.460 28372-28372/com.win.rd.calculator W/System: ClassLoader referenced unknown path: /data/app/com.win.rd.calculator-1/lib/arm
07-23 21:35:36.550 28372-28382/com.win.rd.calculator I/art: Background sticky concurrent mark sweep GC freed 2992(169KB) AllocSpace objects, 0(0B) LOS objects, 52% free, 615KB/1294KB, paused 5.118ms total 79.262ms
07-23 21:35:36.610 28372-28372/com.win.rd.calculator W/art: Before Android 4.1, method android.graphics.PorterDuffColorFilter android.support.graphics.drawable.VectorDrawableCompat.updateTintFilter(android.graphics.PorterDuffColorFilter, android.content.res.ColorStateList, android.graphics.PorterDuff$Mode) would have incorrectly overridden the package-private method in android.graphics.drawable.Drawable
    unsupported multiclient unsolicited response code 1009
07-23 21:35:37.020 28372-28372/com.win.rd.calculator D/AndroidRuntime: Shutting down VM
07-23 21:35:37.030 28372-28372/com.win.rd.calculator E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.win.rd.calculator, PID: 28372
    Theme: themes:{}
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.win.rd.calculator/com.win.rd.calculator.MainActivity}: java.lang.NumberFormatException: Invalid double: ""
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2462)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2522)
        at android.app.ActivityThread.-wrap11(ActivityThread.java)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1363)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:148)
        at android.app.ActivityThread.main(ActivityThread.java:5471)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
     Caused by: java.lang.NumberFormatException: Invalid double: ""
        at java.lang.StringToReal.invalidReal(StringToReal.java:63)
        at java.lang.StringToReal.parseDouble(StringToReal.java:267)
        at java.lang.Double.parseDouble(Double.java:301)
        at java.lang.Double.valueOf(Double.java:338)
        at com.win.rd.calculator.MainActivity.onCreate(MainActivity.java:35)
        at android.app.Activity.performCreate(Activity.java:7125)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1108)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2415)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2522) 
        at android.app.ActivityThread.-wrap11(ActivityThread.java) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1363) 
        at android.os.Handler.dispatchMessage(Handler.java:102) 
        at android.os.Looper.loop(Looper.java:148) 
        at android.app.ActivityThread.main(ActivityThread.java:5471) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

What's going wrong?

Here is my main activity:

package com.win.rd.calculator;

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.TextView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    EditText edt1, edt2;
    TextView txt;
    Button pls, min, mlp, div;

    double numA, numB, result;
    int flag, ecd;

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

        edt1 = (EditText) findViewById(R.id.num1);
        edt2 = (EditText) findViewById(R.id.num2);
        txt = (TextView) findViewById(R.id.res);
        pls = (Button) findViewById(R.id.plus);
        min = (Button) findViewById(R.id.minus);
        mlp = (Button) findViewById(R.id.multiply);
        div = (Button) findViewById(R.id.divide);

        numA = numB = result = flag = 0;

        numA = Double.valueOf(edt1.getText().toString());
        numB = Double.valueOf(edt2.getText().toString());

    }

    public void Operation ( double numA, double numB, int flag){
        if (flag == 1) {
            result = (numA + numB);
        } else if (flag == 2) {
            result = (numA - numB);
        } else if (flag == 3) {
            result = (numA * numB);
        } else if (flag == 4) {
            result = numA / numB;
            if (Double.isInfinite(result)) {
                ecd = 1;
                edt1.setText("");
                edt2.setText("");
                Toast.makeText(this, "Cannot Divide By Zero", Toast.LENGTH_SHORT).show();
            }
            else if (Double.isNaN(result)){
                ecd = 2;
                edt1.setText("");
                edt2.setText("");
                Toast.makeText(this, "0/0 Not possible", Toast.LENGTH_SHORT).show();
            }
        }
    }

    public void Plus (View view){
        txt.setText("+");
        flag = 1;
        if (!edt1.toString().equals("") || !edt2.toString().equals(""))
            Operation(numA, numB, flag);
        else
            Toast.makeText(this, "Empty Field", Toast.LENGTH_SHORT).show();
    }
    public void Minus (View view){
        txt.setText("-");
        flag = 2;
        if (!edt1.toString().equals("") || !edt2.toString().equals(""))
            Operation(numA, numB, flag);
        else
            Toast.makeText(this, "Empty Field", Toast.LENGTH_SHORT).show();
    }

    public void Multiply (View view){
        txt.setText("x");
        flag = 3;
        if (!edt1.toString().equals("") || !edt2.toString().equals(""))
            Operation(numA, numB, flag);
        else
            Toast.makeText(this, "Empty Field", Toast.LENGTH_SHORT).show();
    }

    public void Divide (View view){
        txt.setText("/");
        flag = 4;
        if (!edt1.toString().equals("") || !edt2.toString().equals(""))
            Operation(numA, numB, flag);
        else
            Toast.makeText(this, "Empty Field", Toast.LENGTH_SHORT).show();
    }

    public void Result (View view){
        if (flag == 4) {
            if (ecd == 1)
                txt.setText("Infinite");
            if (ecd == 2)
                txt.setText("NaN");
        }
        else
            txt.setText(String.valueOf(result));
    }
}

Its a simple calculator app.

Double.valueOf() & Double.double.parseDouble() produces the same result right.? What are other typecasting methods in java. Thanks for quick comment.

May be typcasting is done in wrong way? Logs clearly says that number formatting in double.. Please paste your code. — Shadab Siddiqui, Jul 23 '18 at 16:17
Somewhere on line number 35 in your main activity you are doing something wrong — Shadab Siddiqui, Jul 23 '18 at 16:19

score 0 · Accepted Answer · answered Jul 24 '18 at 06:39

0

at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) Caused by: java.lang.NumberFormatException: Invalid double: ""

The error says that you are trying to convert empty string to double which is causing this issue, so you should handle empty strings cases like below

if(edt1.getText().toString() != null && !edt1.getText().toString().isEmpty()){
    numA = Double.valueOf(edt1.getText().toString());
}

answered Jul 24 '18 at 06:39

Fahadsk

1,099
10
24

`edt1.getText().toString() != null` is always "true" so why add it.. Again, `numA = Double.valueOf(edt1.getText().toString()); numB = Double.valueOf(edt2.getText().toString());` this was read in the beginning, so why to read it again under if? – Jovial Joe Jayarson Jul 24 '18 at 10:23
It is just to show that you need to handle empty and null strings before parsing it to double type. – Fahadsk Jul 24 '18 at 11:19
great! happy coding. – Fahadsk Jul 25 '18 at 06:11
Thanks! A tiny discovery: those `...edt1.getText().toString() != null...` codes must not be in `onCreate()` since they are true, the values are not taken in (or read), so I just put them on another function. Anyway thanks! – Jovial Joe Jayarson Jul 26 '18 at 13:45

Main_Activity Launch crashes

1 Answers1