Check if Edittext is empty

Question

Check if Edittext is empty

Asked 8 years, 4 months ago

Viewed 3,996 times

2

Hello guys I’m making an app on android studio but I don’t know exactly how to check if the text fields are empty, I tried the following solution in the code below :

public class MainActivity extends AppCompatActivity {

EditText edt1,edt2;
TextView tv3;
float n1 = 0.70f;


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

    edt1 = (EditText) findViewById(R.id.editText);
    edt2 = (EditText) findViewById(R.id.editText2);
    tv3 = (TextView) findViewById(R.id.textView3);

}


public void calcular(View v){

    double valor1 = Double.parseDouble(edt1.getText().toString());
    double valor2 = Double.parseDouble(edt2.getText().toString());


    double resultado1 = valor1 * n1;

    if (edt1.getText().toString().equals("")){
       tv3.setText("Campo vazio");
    }

    if (edt2.getText().toString().equals("")){
       tv3.setText("Campo vazio");
    }

    if (resultado1 < valor2) {
        tv3.setText("Vale a pena Abastecer com Gasolina");
    }


    else {
        tv3.setText("Vale a pena Abastecer com Alcool");
    }


    }

}

Further by clicking on the run with the empty fields I get the following error:

08-08 15:21:53.288 25012-25012/com.dolardehoje.formulario W/dalvikvm: threadid=1: thread exiting with uncaught exception (group=0x41a19930)
08-08 15:21:53.298 25012-25012/com.dolardehoje.formulario E/AndroidRuntime: FATAL EXCEPTION: main
    java.lang.IllegalStateException: Could not execute method for android:onClick
        at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:293)
        at android.view.View.performClick(View.java:4380)
        at android.view.View$PerformClick.run(View.java:18094)
        at android.os.Handler.handleCallback(Handler.java:725)
        at android.os.Handler.dispatchMessage(Handler.java:92)
        at android.os.Looper.loop(Looper.java:137)
        at android.app.ActivityThread.main(ActivityThread.java:5279)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:511)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
        at dalvik.system.NativeStart.main(Native Method)
     Caused by: java.lang.reflect.InvocationTargetException
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:511)
        at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288)
        at android.view.View.performClick(View.java:4380) 
        at android.view.View$PerformClick.run(View.java:18094) 
        at android.os.Handler.handleCallback(Handler.java:725) 
        at android.os.Handler.dispatchMessage(Handler.java:92) 
        at android.os.Looper.loop(Looper.java:137) 
        at android.app.ActivityThread.main(ActivityThread.java:5279) 
        at java.lang.reflect.Method.invokeNative(Native Method) 
        at java.lang.reflect.Method.invoke(Method.java:511) 
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869) 
        at dalvik.system.NativeStart.main(Native Method) 
     Caused by: java.lang.NumberFormatException: Invalid double: ""
        at java.lang.StringToReal.invalidReal(StringToReal.java:63)
        at java.lang.StringToReal.parseDouble(StringToReal.java:248)
        at java.lang.Double.parseDouble(Double.java:295)
        at com.dolardehoje.formulario.MainActivity.calcular(MainActivity.java:38)
        at java.lang.reflect.Method.invokeNative(Native Method) 
        at java.lang.reflect.Method.invoke(Method.java:511) 
        at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288) 
        at android.view.View.performClick(View.java:4380) 
        at android.view.View$PerformClick.run(View.java:18094) 
        at android.os.Handler.handleCallback(Handler.java:725) 
        at android.os.Handler.dispatchMessage(Handler.java:92) 
        at android.os.Looper.loop(Looper.java:137) 
        at android.app.ActivityThread.main(ActivityThread.java:5279) 
        at java.lang.reflect.Method.invokeNative(Native Method) 
        at java.lang.reflect.Method.invoke(Method.java:511) 
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869) 
        at dalvik.system.NativeStart.main(Native Method)

Possible duplicate of How to test if an Edittext is empty?

– ramaral

2016/08/08 at 14:05
Try it this way: Textutils.isEmpty(edt1.gettext(). toString())

– Thiago Luiz Domacoski

2016/08/08 at 14:06
1

Behold How to consider an empty Edittext as "0"

– ramaral

2016/08/08 at 14:10

6 answers

7

The mistake happens because you are trying to get one Double of a string that is null or has no convertible value.

Change the code so that validation of Edittext before obtaining the values in Double

public void calcular(View v){

    if (edt1.getText().toString().trim().equals("") ||
        edt2.getText().toString().trim().equals("")){

       Toast.makeText(this, "Valores incorretos",Toast.LENGTH_LONG).show();

    }else{
        double valor1 = Double.parseDouble(edt1.getText().toString());
        double valor2 = Double.parseDouble(edt2.getText().toString());

        double resultado1 = valor1 * n1;

        if (resultado1 < valor2) {
            tv3.setText("Vale a pena Abastecer com Gasolina");
        }
        else {
            tv3.setText("Vale a pena Abastecer com Alcool");
        }
    }
}

To ensure that the user only enters valid values (numbers) add the following attributes to the Edittext edt1 and edt2

android:text="0" 
android:inputType="numberDecimal"

1

managed using your solution, thank you!

– denis

2016/08/08 at 18:40

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by Edumachdo • **160** points · Answer 1 · 2016-08-08T14:07:32+00:00

3

If what you want is just check if the field is empty try to use the following line:

if(edt1.getText().toString().equals("")){
   //Colocar o que vc quer que aconteça caso esteja vazio.
}

or else:

if(!edt1.getText().toString().equals("")){
   //Colocar o que vc quer que aconteça caso não esteja vazio.
}

I’m basically choosing the field and picking up what’s in it. And with . What("") I’m comparing it to an empty field.

I hope I’ve helped.

Even with this error when I click to run and the error app

– denis

2016/08/08 at 15:56
Edit your question and post the error q is giving.

– Edumachdo

2016/08/08 at 16:22
edited with updated code

– denis

2016/08/08 at 16:39
Re-edit and place the error displayed.

– Edumachdo

2016/08/08 at 16:44
The error is the following "your application has stopped"

– denis

2016/08/08 at 16:50
I’m flando the "LOG" q is presented on the "Android Monitor" at the bottom of android studio.

– Edumachdo

2016/08/08 at 16:58
added the error log

– denis

2016/08/08 at 18:26

Show 2 more comments

by Adliano Alves • **306** points · Answer 2 · 2016-08-09T01:05:14+00:00

"thread exiting with uncaught Exception"

declare value1 and value2 global and use it here :

try
{
    valor1 = Double.parseDouble(edt1.getText().toString());
    valor2 = Double.parseDouble(edt2.getText().toString());
} 
catch(NumberFormatException e)
{
    tv3.setText("Valor Invalido");
}

by Edumachdo • **160** points · Answer 3 · 2016-08-09T10:14:56+00:00

Based on what the ramaral did, because this correct, I would only change a few points and add a few lines for the code to be more complete.

public void calcular(View v){

   if (edt1.getText().toString().trim().equals("") &&
       edt2.getText().toString().trim().equals("")){

       Toast.makeText(this, "Os dois campos estao vazios!",Toast.LENGTH_LONG).show();

   }else if(edt1.getText().toString().trim().equals("")){

       Toast.makeText(this, "O primeiro campo esta vazio",Toast.LENGTH_LONG).show();

   }else if(edt2.getText().toString().trim().equals("")){

       Toast.makeText(this, "O segundo campo esta vazio",Toast.LENGTH_LONG).show();

   }else{

       double valor1 = Double.parseDouble(edt1.getText().toString());
       double valor2 = Double.parseDouble(edt2.getText().toString());

       double resultado1 = valor1 * n1;

       if (resultado1 < valor2) {
           tv3.setText("Vale a pena Abastecer com Gasolina");

       }else {
           tv3.setText("Vale a pena Abastecer com Alcool");
       }
   }
}

I know few changes, but I hope I can help

by António Macave • **486** points · Answer 4 · 2016-08-09T10:26:23+00:00

1

You can do it like this:

if (edt1.getText().toString().isEmpty()) {

   //Informar que o campo 1 está vazio.

}

If you have a blank space, it will not validate.

– user28595

2016/08/09 at 10:27

by viana • **27,141** points · Answer 5 · 2016-08-08T17:31:00+00:00

You can check this way by creating the following function, which will check if it has white space and if the string size is less than 1.

private boolean isEmpty(EditText etText) {
        String text = etText.getText().toString().trim();
        if (text.length()<1)
            return true;
        return false;
}