CODEWITHSUNDEEP
javaandroidxml
Alex
Alex

Reputation: 25

Android Java, why my button crashes my application

Why when my Edit Text in XML are empty and when I click on the button envoyerListener my application crashes?

You could find below the Java code, which is maybe not that good, but the application runs well. Only when I click on the button envoyer with my two EditTexts being empty my application crashes.

        import android.support.v7.app.AppCompatActivity;
        import android.os.Bundle;
        import android.text.Editable;
        import android.text.TextWatcher;
        import android.view.View;
        import android.view.View.OnClickListener;
        import android.widget.Button;
        import android.widget.EditText;
        import android.widget.TextView;
        import android.content.Intent;

        public class MainActivity extends AppCompatActivity {

        private final String defaut = "result";

        EditText price = null;
        EditText rent = null;
        TextView result = null;
        Button buttenvoyer = null;
        Button buttrent = null;
        Button buttprice = null;
        Button buttinfo = null;
        Button buttclear = null;


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

            price = (EditText) findViewById(R.id.price);
            rent = (EditText) findViewById(R.id.rent);
            result = (TextView) findViewById(R.id.result);
            buttenvoyer = (Button) findViewById(R.id.buttcalculate);
            buttrent = (Button) findViewById(R.id.buttrent);
            buttprice = (Button) findViewById(R.id.buttprice);
            buttinfo = (Button) findViewById(R.id.buttinfo);
            buttclear = (Button) findViewById(R.id.buttclear);

            price.addTextChangedListener(textWatcher);
            rent.addTextChangedListener(textWatcher);
            buttenvoyer.setOnClickListener(envoyerListener);
            buttrent.setOnClickListener(rentListener);
            buttprice.setOnClickListener(priceListener);
            buttinfo.setOnClickListener(infoListener);
            buttclear.setOnClickListener(clearListener);
        }

        private TextWatcher textWatcher = new TextWatcher() {
            @Override
            public void onTextChanged(CharSequence s, int start, int befor, int count) {
                result.setText(defaut);
            }

            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
            }

            @Override
            public void afterTextChanged(Editable s) {
            }
        };

        private OnClickListener envoyerListener = new OnClickListener() {
            @Override
            public void onClick(View v) {
                String p = price.getText().toString();
                String r = rent.getText().toString();

                float pValue = Float.valueOf(p);
                float rValue = Float.valueOf(r);

                float resultat = rValue * 100 / pValue;
                result.setText("the profit is " + String.valueOf(resultat) + " %");
            }
        };

        private OnClickListener rentListener = new OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent jumpage = new Intent(MainActivity.this, Rent.class);
                startActivity(jumpage);
            }
        };

        private OnClickListener priceListener = new OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent jumpage = new Intent(MainActivity.this, Price.class);
                startActivity(jumpage);
            }
        };

        private OnClickListener infoListener = new OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent jumpage = new Intent(MainActivity.this, Infoam.class);
                startActivity(jumpage);
            }
        };

        private OnClickListener clearListener = new OnClickListener() {
            @Override
            public void onClick(View v) {
                price.getText().clear();
                rent.getText().clear();
                result.setText(defaut);
            }
        };


    }

Upvotes: 0

Views: 69

Answers (1)

Yoshi_64
Yoshi_64

Reputation: 306

You say:

only when I click on the button envoyer with my two Edit text empty my application crash

So the issue is here:

String p = price.getText().toString();
String r = rent.getText().toString();

float pValue = Float.valueOf(p);
float rValue = Float.valueOf(r);

In your listener you don't check these strings. If they are empty, which happens when you grab empty text, then you have no values to parse. And as a result it throws NumberFormatException.

You have to perform some check when you get the text p and r because you'll just have an empty string "" which cannot be cast into anything and choose to either set the value of the String to 0 or choose to set your float value to 0.

I would do something like:

float pValue;
if(p.isEmpty())
{
    pValue = 0;
}
else
{
    pvalue = Float.valueOf(p);
}

Upvotes: 3

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