Application keeps Crashing

Question

My application keeps on crashing, and I cannot figure out why. I am suspecting that there is something wrong with the getReactants() method because the button is working just fine and can display any other text I put in the beq.setText().

There are no errors in the logcat, the threads are simply suspended and my device says that the application is not responding, and says I can either wait or kill the app.

Here is my code.

Java

package me.finalproject.com.apchemchemolyapp;

import android.app.Fragment;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import java.util.ArrayList;
import java.io.Serializable;


/**
 * Created by Shishir on 6/9/2016.
 */
public class stoich_fragment extends Fragment implements View.OnClickListener, Serializable
{
    View rootview;
    int i = 0;
    ArrayList<Integer> arr = new ArrayList<>();
    ArrayList<String> elements = new ArrayList<>();
    boolean getElements = true;
    String s1;
    String element = "";
    EditText reactants;
    TextView beq;
    Button go;
    int temp;
    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
    {
        rootview = inflater.inflate(R.layout.stoich_layout, container, false);
        reactants = (EditText) rootview.findViewById(R.id.reactants);
        go = (Button) rootview.findViewById(R.id.button);
        go.setOnClickListener(this);
        return rootview;
    }
    public void onClick(View v)
    {
        getReactants(s1);
        beq = (TextView) rootview.findViewById(R.id.balanced_equation);
        beq.setText(s1);
    }
    public void getReactants(String s)
    {
        String reactant = reactants.getText().toString();
        //saying that reactants is null even after it went through the onCreateView method
        String re = reactant.replaceAll("\\s+","");
        while(getElements)
        {
            String let = re.substring(i, i+1);
            if(let.compareTo(let.toLowerCase()) > 0)
            {
                element += let;
                if(i == re.length()-1 || i == re.length())
                {
                    elements.add(element);
                    if(re.substring(re.length()-1).equals("2")||re.substring(re.length()-1).equals("3")||re.substring(re.length()-1).equals("4")||re.substring(re.length()-1).equals("5")||re.substring(re.length()-1).equals("6")||re.substring(re.length()-1).equals("7")||re.substring(re.length()-1).equals("8")||re.substring(re.length()-1).equals("9"))
                    {
                        arr.add(Integer.parseInt(re.substring(re.length()-1)));
                    }
                    else
                    {
                        arr.add(1);
                        elements.add(re.substring(re.length()-1));
                        arr.add(1);
                    }
                    getElements = false;
                }
                else if(re.substring(i+1, i+2).compareTo(re.substring(i+1, i+2).toLowerCase()) != 0)
                {
                    if(!re.substring(i+1,i+2).equals("2")||!re.substring(i+1,i+2).equals("3")||!re.substring(i+1,i+2).equals("4")||!re.substring(i+1,i+2).equals("5")||!re.substring(i+1,i+2).equals("6")||!re.substring(i+1,i+2).equals("7")||!re.substring(i+1,i+2).equals("8")||!re.substring(i+1,i+2).equals("9"))
                    {
                        temp = 1;
                        arr.add(temp);
                    }
                }
            }
            else if(let.compareTo(let.toLowerCase()) == 0)
            {
                element += let;
                if(i == re.length()-1 || i == re.length())
                {
                    elements.add(element);
                    if(re.substring(re.length()-1).equals("2")||re.substring(re.length()-1).equals("3")||re.substring(re.length()-1).equals("4")||re.substring(re.length()-1).equals("5")||re.substring(re.length()-1).equals("6")||re.substring(re.length()-1).equals("7")||re.substring(re.length()-1).equals("8")||re.substring(re.length()-1).equals("9"))
                    {
                        arr.add(Integer.parseInt(re.substring(re.length()-1)));
                    }
                    else
                    {
                        arr.add(1);
                        elements.add(re.substring(re.length()-1));
                        arr.add(1);
                    }
                    getElements = false;
                }
                else if(!re.substring(i+1,i+2).equals("2")||re.substring(i+1,i+2).equals("3")||re.substring(i+1,i+2).equals("4")||re.substring(i+1,i+2).equals("5")||re.substring(i+1,i+2).equals("6")||re.substring(i+1,i+2).equals("7")||re.substring(i+1,i+2).equals("8")||re.substring(i+1,i+2).equals("9"))
                {
                    temp = 1;
                    arr.add(temp);
                }
            }
            else if (let.equals("2")||let.equals("3")||let.equals("4")||let.equals("5")||let.equals("6")||let.equals("7")||let.equals("8")||let.equals("9"))
            {
                temp = Integer.parseInt(let);
                arr.add(temp);
                elements.add(element);
                element = "";
            }
            i++;
            if(i == re.length()+1)
            {
                getElements = false;
            }
        }
        // displays the elements isolated on the reactant side
        // to test to make sure my logic works
        for(int a = 0; a<elements.size(); a++)
        {
            s += (elements.get(a) + " : " + arr.get(a) + "\n");
        }
    }
}

XML

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent" android:layout_height="match_parent">

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/reactants"
        android:layout_alignParentTop="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_marginTop="95dp"
        android:textSize="20sp"
        android:inputType="text" />

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/products"
        android:layout_alignBottom="@+id/reactants"
        android:layout_alignParentRight="true"
        android:layout_alignParentEnd="true"
        android:textSize="20sp"
        android:inputType="text" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/balanced_equation"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true"
        android:textSize="30sp" />

<!--should make text bold and black-->
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/beq"
        android:id="@+id/title"
        android:textSize="35sp"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:textStyle = "bold"/>

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/button"
        android:id="@+id/button"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="45dp" />

</RelativeLayout>

Answer 1

This messages means your application is doing too much work on it's main thread (UI Tread).

I suggest to put getReactants() in an AsyncTask and show the result when all proccesses finished without blocking the main thread.

Answer 2

Looking at your code, it seems that you probably have an infinite loop. Try to set your getElements flag to false at the end of your while loop to make sure it will be executed. Must be something like:

    while(getElements)
    {
        String let = re.substring(i, i+1);
        if(let.compareTo(let.toLowerCase()) > 0)
        {
            element += let;
            if(re.substring(i+1, i+2).compareTo(re.substring(i+1, i+2).toLowerCase()) != 0)
            {
                if(!re.substring(i+1,i+2).equals("2")||re.substring(i+1,i+2).equals("3")||re.substring(i+1,i+2).equals("4")||re.substring(i+1,i+2).equals("5")||re.substring(i+1,i+2).equals("6")||re.substring(i+1,i+2).equals("7")||re.substring(i+1,i+2).equals("8")||re.substring(i+1,i+2).equals("9"))
                {
                    temp = 1;
                    arr.add(temp);
                }
            }
            i++;
        }
        else if(let.compareTo(let.toLowerCase()) == 0)
        {
            element += let;
            if(!re.substring(i+1,i+2).equals("2")||re.substring(i+1,i+2).equals("3")||re.substring(i+1,i+2).equals("4")||re.substring(i+1,i+2).equals("5")||re.substring(i+1,i+2).equals("6")||re.substring(i+1,i+2).equals("7")||re.substring(i+1,i+2).equals("8")||re.substring(i+1,i+2).equals("9"))
            {
                temp = 1;
                arr.add(temp);
            }
            i++;
        }
        else if (let.equals("2")||let.equals("3")||let.equals("4")||let.equals("5")||let.equals("6")||let.equals("7")||let.equals("8")||let.equals("9"))
        {
            temp = Integer.parseInt(let);
            arr.add(temp);
            elements.add(element);
            element = "";
        }

        if(i == re.length())
        {
            getElements = false;
        }
        // must have an else statement here or else you will have an infinite loop if your condition is always false.

    }

Answer 3

You are not incrementing i in some cases, you should have to move i++ to the end of your while to avoid an infinite loop

i has to be incremented in all cases, consider something like this:

if () {
`enter code here`
}
else if () {
`enter code here`
}
else if () {
`enter code here`
}
i++;
if(i == re.length()) {
    getElements = false;
}