java - Why does my app crash without any errors?

App crashes and I am getting these errors:

---

FATAL EXCEPTION: main
Process: com.example.ayyan.jellybeanestimator, PID: 2960

java.lang.RuntimeException: Unable to start activity

ComponentInfo{com.example.ayyan.jellybeanestimator/com.example.ayyan.jellybeanestimator.MainActivity}:
java.lang.NumberFormatException: empty String
at
android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2646)
at
android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707)
at android.app.ActivityThread.-wrap12(ActivityThread.java)
at

android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6077)
at java.lang.reflect.Method.invoke(Native Method)
at
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
Caused by: java.lang.NumberFormatException: empty String
at

java.lang.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1071)
at java.lang.Double.parseDouble(Double.java:547)
at
com.example.ayyan.jellybeanestimator.MainActivity.onCreate(MainActivity.java:25)
at android.app.Activity.performCreate(Activity.java:6662)
at
android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118)
at
android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2599)
at

android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707) 
at android.app.ActivityThread.-wrap12(ActivityThread.java) 
at
android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:154) 
at android.app.ActivityThread.main(ActivityThread.java:6077) 
at java.lang.reflect.Method.invoke(Native Method) 
at
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865) 

at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)

package com.example.ayyan.jellybeanestimator;

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

import android.content.Intent;
import android.view.View;

public class MainActivity extends AppCompatActivity {
EditText jellyBeanLength, jellyBeanDiameter, jarSizeVolume;
double jellybeantall, jellybeanfat, jellybeanspace;
double loadFactor = .698;
TextView answer;

@Override

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

    jellyBeanLength = (EditText) findViewById (R.id.length);
    jellyBeanDiameter = (EditText) findViewById (R.id.diameter);
    jarSizeVolume = (EditText) findViewById (R.id.jarsize);
    jellybeantall = Double.parseDouble(jellyBeanLength.getText().toString());
    jellybeanfat = Double.parseDouble(jellyBeanDiameter.getText().toString());
    jellybeanspace = Double.parseDouble(jarSizeVolume.getText().toString());

    answer = (TextView) findViewById (R.id.answer);
    Button calculate = (Button) findViewById (R.id.calculate);
    calculate.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            startActivity(new Intent(MainActivity.this, MainActivity.class));
        }
    });




    double volumeOfOneJellyBean =  ((3.14159265359/6)*(jellybeanfat*jellybeanfat)*jellybeantall);
    double volumeofBeans = (jellybeanspace*loadFactor);
    float numberOfBeans = (float)Math.round (volumeofBeans/volumeOfOneJellyBean);
    answer.setText("You have this amount of beans in your jar" + numberOfBeans);
}

}