How to display Double value on edittext- android

Question

I am creating an application which takes numerical vales from the edittext, does calculation on them like calculation of discount, change of currency etc and then display them on another edittext.

I am converting values from string to Double and then again displaying it in the screen by converting double to string. I have marked the line where calculation and displaying of values takes place.

My problem is that, nothing is displayed on the edittext and no error is generated in the logcat.

public class Calculator extends Activity implements View.OnClickListener {

    EditText carat,list,price,total,discount,converter,discamt,caratrs;
    Button submit;
    Button one, two, three, four, five, six, seven, eight, nine, zero, clear,dot,calc;
    double int_list=0,int_carat=0,int_discount=0,int_converter=0,int_price=0,int_total=0,int_discamt=0,int_pricers=0;

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

       carat=(EditText)findViewById(R.id.carat);
        list=(EditText)findViewById(R.id.list);
        price=(EditText)findViewById(R.id.price);
        total=(EditText)findViewById(R.id.total);
        discount=(EditText)findViewById(R.id.discount);
        converter=(EditText)findViewById(R.id.converter);
        discamt=(EditText)findViewById(R.id.discamt);
        caratrs=(EditText)findViewById(R.id.caratrs);

        submit=(Button)findViewById(R.id.submit);
        calc=(Button)findViewById(R.id.calculate);

        one = (Button) findViewById(R.id.one);
        two = (Button) findViewById(R.id.two);
        three = (Button) findViewById(R.id.three);
        four = (Button) findViewById(R.id.four);
        five = (Button) findViewById(R.id.five);
        six = (Button) findViewById(R.id.six);
        seven = (Button) findViewById(R.id.seven);
        eight = (Button) findViewById(R.id.eight);
        nine = (Button) findViewById(R.id.nine);
        zero = (Button) findViewById(R.id.zero);
        clear=(Button)findViewById(R.id.clear);
        dot=(Button)findViewById(R.id.dot);



        price.setInputType(InputType.TYPE_NULL);
        total.setInputType(InputType.TYPE_NULL);
        carat.setInputType(InputType.TYPE_NULL);
        list.setInputType(InputType.TYPE_NULL);
        converter.setInputType(InputType.TYPE_NULL);
        discount.setInputType(InputType.TYPE_NULL);
        discamt.setInputType(InputType.TYPE_NULL);
        caratrs.setInputType(InputType.TYPE_NULL);

        try{
            one.setOnClickListener(this);

            two.setOnClickListener(this);

            three.setOnClickListener(this);

            four.setOnClickListener(this);

            five.setOnClickListener(this);

            six.setOnClickListener(this);

            seven.setOnClickListener(this);

            eight.setOnClickListener(this);

            nine.setOnClickListener(this);

            zero.setOnClickListener(this);


            dot.setOnClickListener(this);

        }
        catch(Exception e){

        }


        clear.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(carat.isFocused())
                {
                    carat.setText("");
                }
                else if(price.isFocused())
                {
                    price.setText("");
                }
                else if(total.isFocused())
                {
                    total.setText("");
                }
                else if(list.isFocused())
                {
                    list.setText("");
                }
                else if(discount.isFocused())
                {
                    discount.setText("");
                }
                else if(converter.isFocused())
                {
                    converter.setText("");
                }
                else if(discamt.isFocused())
                {
                    discamt.setText("");
                }
                else if(caratrs.isFocused())
                {
                    caratrs.setText("");
                }
            }
        });

---------------------------This is where all the calculation takes place including displaying the value on the edittext-----------------------------



    calc.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            try {
                int_list = Double.parseDouble(list.getText().toString());
                int_carat = Double.parseDouble(carat.getText().toString());
                int_discount = Double.parseDouble(discount.getText().toString());
                int_converter = Double.parseDouble(converter.getText().toString());
                int_discamt = Double.parseDouble(discamt.getText().toString());


                int_discamt = (int_list * int_discount) / 100;
                int_price = int_list - int_discamt;
                int_pricers = int_price * int_converter;
                int_total = int_price * int_converter * int_carat;


                price.setText(Double.toString(int_price));
                discamt.setText(Double.toString(int_discamt));
                caratrs.setText(Double.toString(int_pricers));
                total.setText(Double.toString(int_total));
            }
            catch(NumberFormatException e)
            {
                e.printStackTrace();
            }

        }
    });

     }


    @Override
    public void onClick(View v) {



        if(carat.isFocused())
        {
            carat.setText(carat.getText().toString() + ((Button) v).getText());
        }

        else if(list.isFocused())
        {
            list.setText(list.getText().toString() +((Button)v).getText());
        }
         else if(discount.isFocused())
        {
            discount.setText(discount.getText().toString() +((Button)v).getText());
        }
        else if(converter.isFocused())
        {
            converter.setText(converter.getText().toString() +((Button)v).getText());
        }


    }

}

This is what i am getting in logcat

05-07 18:00:14.918  14299-14299/com.diamond.traders W/System.err﹕ java.lang.NumberFormatException: Invalid double: ""
05-07 18:00:14.918  14299-14299/com.diamond.traders W/System.err﹕ at java.lang.StringToReal.invalidReal(StringToReal.java:63)
05-07 18:00:14.918  14299-14299/com.diamond.traders W/System.err﹕ at java.lang.StringToReal.parseDouble(StringToReal.java:248)
05-07 18:00:14.918  14299-14299/com.diamond.traders W/System.err﹕ at java.lang.Double.parseDouble(Double.java:295)
05-07 18:00:14.918  14299-14299/com.diamond.traders W/System.err﹕ at com.diamond.traders.Calculator$2.onClick(Calculator.java:176)
05-07 18:00:14.918  14299-14299/com.diamond.traders W/System.err﹕ at android.view.View.performClick(View.java:4438)
05-07 18:00:14.918  14299-14299/com.diamond.traders W/System.err﹕ at android.view.View$PerformClick.run(View.java:18422)
05-07 18:00:14.918  14299-14299/com.diamond.traders W/System.err﹕ at android.os.Handler.handleCallback(Handler.java:733)
05-07 18:00:14.918  14299-14299/com.diamond.traders W/System.err﹕ at android.os.Handler.dispatchMessage(Handler.java:95)
05-07 18:00:14.918  14299-14299/com.diamond.traders W/System.err﹕ at android.os.Looper.loop(Looper.java:136)
05-07 18:00:14.918  14299-14299/com.diamond.traders W/System.err﹕ at android.app.ActivityThread.main(ActivityThread.java:5017)
05-07 18:00:14.918  14299-14299/com.diamond.traders W/System.err﹕ at java.lang.reflect.Method.invoke(Native Method)
05-07 18:00:14.918  14299-14299/com.diamond.traders W/System.err﹕ at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
05-07 18:00:14.918  14299-14299/com.diamond.traders W/System.err﹕ at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)

Answer 1

You have to put validation for all EditText field.

calc.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String list = list.getText().toString().trim();
                String carat = carat.getText().toString().trim();
                String discount = discount.getText().toString().trim();
                String converter = converter.getText().toString().trim();
                String discamt = discamt.getText().toString().trim();

                if(list.length() > 0 && carat.length() > 0 && discount.length() > 0
                        && converter.length() > 0 && discamt.length() > 0 )
                {
                     try {
                            int_list = Double.parseDouble(list.getText().toString());
                            int_carat = Double.parseDouble(carat.getText().toString());
                            int_discount = Double.parseDouble(discount.getText().toString());
                            int_converter = Double.parseDouble(converter.getText().toString());
                            int_discamt = Double.parseDouble(discamt.getText().toString());


                            int_discamt = (int_list * int_discount) / 100;
                            int_price = int_list - int_discamt;
                            int_pricers = int_price * int_converter;
                            int_total = int_price * int_converter * int_carat;


                            price.setText(Double.toString(int_price));
                            discamt.setText(Double.toString(int_discamt));
                            caratrs.setText(Double.toString(int_pricers));
                            total.setText(Double.toString(int_total));
                     }
                    catch(NumberFormatException e)
                    {
                        e.printStackTrace();
                    }
                }else
                {
                    Toast.makeText(context, "Please enter all value.", Toast.LENGTH_SHORT).show();
                }
            }
            });

Answer 2

Double.toString() is not recommended by lint, because it doesn't take into account locale settings. Consider using String.format(locale, "%f", 123D);
You can replace locale with Locale.US, for example.

Answer 3

Use

double doubleValue;

edittext.setText(""+doubleValue);

 OR

edittext.setText(String.valueOf(doubleValue));

Answer 4

 java.lang.NumberFormatException: Invalid double: ""
......
 m.err﹕ at java.lang.Double.parseDouble(Double.java:295)

It simply states that one of your String which you are trying to parse as double is "".

int_list = Double.parseDouble(list.getText().toString());
int_carat = Double.parseDouble(carat.getText().toString());
int_discount = Double.parseDouble(discount.getText().toString());
int_converter = Double.parseDouble(converter.getText().toString());
int_discamt = Double.parseDouble(discamt.getText().toString());

Make sure your EditText have value.

And you can use String.valueOf(total) to convert to String.

NOTE:

• Make sure your EditText is not Empty use ed.getText().toString().equals("")(some other validation may be needed this is just an example) to validate and surround code with try catch when there is possibility of Exception.

• It may be possible you have placed id at wrong EditText which remains empty during calculation so please check.

Answer 5

It seems like you are trying to parse an empty String as a double. You should check with:

if (edittext.getText().length > 0)