java.lang.IllegalStateException Not sure it is it with the data type?

Question

This is my first code in kotlin

activity_main

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="tenge.millionaire.MainActivity">

    <EditText
        android:id="@+id/monthlysalary"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="16dp"
        android:ems="10"
        android:hint="Enter monthly salary"
        android:inputType="textPersonName"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.502"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/perday"
        android:layout_width="wrap_content"
        android:layout_height="0dp"
        android:layout_marginTop="56dp"
        android:text="TextView"
        android:textSize="18sp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/monthlysalary" />

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="296dp"
        android:text="Show me :)"
        android:onClick="CaculateAge"
        android:background="@color/colorPrimary"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/perday" />
</android.support.constraint.ConstraintLayout>

and the MainActivity is

package tenge.millionaire

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        perday.setText("");
    }

    public fun CaculateAge(view: View){
        val salary: String = perday.text.toString();
        val perday1 = salary.toInt()/30;
        perday.setText("Per day you earn $perday1")
    }
}

Not sure what is wrong with the function or is it with the datatype ? and the error is

FATAL EXCEPTION: main Process: tenge.millionaire, PID: 687 java.lang.IllegalStateException: Could not execute method for android:onClick at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:293) at android.view.View.performClick(View.java:6213) at android.widget.TextView.performClick(TextView.java:11074) at android.view.View$PerformClick.run(View.java:23645) at android.os.Handler.handleCallback(Handler.java:751) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:154) at android.app.ActivityThread.main(ActivityThread.java:6692) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1468) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1358) Caused by: java.lang.reflect.InvocationTargetException at java.lang.reflect.Method.invoke(Native Method) at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288) at android.view.View.performClick(View.java:6213) at android.widget.TextView.performClick(TextView.java:11074) at android.view.View$PerformClick.run(View.java:23645) at android.os.Handler.handleCallback(Handler.java:751) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:154) at android.app.ActivityThread.main(ActivityThread.java:6692) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1468) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1358) Caused by: java.lang.NumberFormatException: For input string: "" at java.lang.Integer.parseInt(Integer.java:533) at java.lang.Integer.parseInt(Integer.java:556) at tenge.millionaire.MainActivity.CaculateAge(MainActivity.kt:18) at java.lang.reflect.Method.invoke(Native Method) at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288) at android.view.View.performClick(View.java:6213) at android.widget.TextView.performClick(TextView.java:11074) at android.view.View$PerformClick.run(View.java:23645) at android.os.Handler.handleCallback(Handler.java:751) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:154) at android.app.ActivityThread.main(ActivityThread.java:6692) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1468) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1358)

Martin Lund Martin Lund · Accepted Answer · 2017-09-29T08:34:19

perday.setText("");

Then later you are trying to take this value and put in here:

val salary: String = perday.text.toString();
val perday1 = salary.toInt()/30;

Salary right now is just an empty string, and there it crashes.

 Caused by: java.lang.NumberFormatException: For input string: ""

You need to actually have perday contain a number. Right now you are saying "".toInt() which causes the NumberFormatException

java.lang.IllegalStateException Not sure it is it with the data type?

1 Answers