I get the following error in android studio

Question

I get the following error in android studio

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#1 by (0 votes)
#2 by (-1 votes)

-2

Error message in Logcat

E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.admin.tallerandroid.fede.tallerandroid, PID: 1833
              java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.admin.tallerandroid.fede.tallerandroid/com.example.admin.tallerandroid.fede.tallerandroid.TallerAndroid}: java.lang.NumberFormatException: Invalid int: ""
                  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2184)
                  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2233)
                  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:5001)
                  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:785)
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
                  at dalvik.system.NativeStart.main(Native Method)
               Caused by: java.lang.NumberFormatException: Invalid int: ""
                  at java.lang.Integer.invalidInt(Integer.java:137)
                  at java.lang.Integer.parseInt(Integer.java:358)
                  at java.lang.Integer.parseInt(Integer.java:331)
                  at com.example.admin.tallerandroid.fede.tallerandroid.TallerAndroid.onCreate(TallerAndroid.java:24)
                  at android.app.Activity.performCreate(Activity.java:5231)
                  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
                  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2148)
                  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2233) 
                  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:5001) 
                  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:785) 
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601) 
                  at dalvik.system.NativeStart.main(Native Method)

The following code is summarized, from this point on it gives the same error

package com.example.admin.tallerandroid.fede.tallerandroid;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class TallerAndroid extends AppCompatActivity {
    Button btn;
    TextView txt;
    EditText v1;
    TextView res;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_taller_android);

        this.btn=(Button)this.findViewById(R.id.btn1);
        this.txt=(TextView)this.findViewById(R.id.textView) ;
        this.v1=(EditText)this.findViewById(R.id.val1) ;

        final String vv1 = v1.getText().toString();
        final int a = Integer.parseInt(vv1);
    }
}

XML

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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=".TallerAndroid">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="51dp"
        android:textSize="40px"
        android:text="@string/sumar" />

    <Button
        android:id="@+id/btn1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignEnd="@+id/textView"
        android:layout_centerVertical="true"
        android:text="@string/btn1" />

    <EditText
        android:id="@+id/val1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="109dp"
        android:ems="10"
        android:inputType="number" />

    <EditText
        android:id="@+id/val2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="161dp"
        android:ems="10"
        android:inputType="number" />

    <TextView
        android:id="@+id/resultado"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentStart="true"
        android:layout_marginBottom="152dp"
        android:layout_marginStart="139dp"
        android:text="TextView" />

</RelativeLayout>

java android android-studio

asked by Federico M 03.08.2018 в 17:05

source

2 answers

-1

the error is found in the following lines: final String vv1 = v1.getText().toString(); final int a = Integer.parseInt(vv1);

The problem is that you are trying to convert an empty String to an entire String, which is incorrect.

in the LogCat tells you the error: java.lang.NumberFormatException: Invalid int: ""

The double quotes means empty, what you can do to solve the error is the following: int a ; if (vv1.isEmpty()) { a = 0; }else{ a = Integer.parseInt(vv1); }

This way you avoid the error when initializing your variable a.

answered by 03.08.2018 в 17:28

Error: cout does not type a name Schedule an enter in java? [closed]

score 0 · Accepted Answer

The problem is that you are wanting to parse an empty string as an integer. The sequence in your activity is: - the activity is created - the contents of v1 are saved in vv1. Here v1 is empty because the activity is just created. - Attempt to convert the content of vv1 (still empty for the above) to integer. That throws the exception.

Notice that the log says Invalid int: "" that double quote indicates that you are trying to convert an empty string.

You should make sure vv1 is not empty and only contains numbers before pairing it