Clicking button freeze application

Question

When i click the button(labels in this code as mbutton) my application freezes for seemingly no reason. the logcat give no information on the cause of this freeze. the code for the entire class is below along with the XML for the class below it

Code

public class WorkoutChoice extends Activity
{
 private TextView mDateDisplay,cDateDisplay;
 private Button mPickDate;
 private int mYear,mMonth,mDay;
 private int cYear,cMonth,cDay;
 static final int DATE_DIALOG_ID = 0;
 Button   mButton;
 EditText cweight,nweight;
 TextView t,c;
 String s,s2,cDate,mDate;
 int current,target;
 DataBaseHelper db = new DataBaseHelper(this);
@Override
public void onCreate(Bundle savedInstanceState) 
{
    super.onCreate(savedInstanceState);

    requestWindowFeature(Window.FEATURE_NO_TITLE);
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);
    setContentView(R.layout.choice);
    final Context context = getApplicationContext();
    final int duration = Toast.LENGTH_SHORT;

    mDateDisplay = (TextView) findViewById(R.id.dateDisplay);
    cDateDisplay = (TextView) findViewById(R.id.Current);
    mPickDate = (Button) findViewById(R.id.pickDate);
    mPickDate.setOnClickListener(new View.OnClickListener(){
        public void onClick(View v) {
            showDialog(DATE_DIALOG_ID);
        }
    });
    final Calendar c = Calendar.getInstance();
    cYear = c.get(Calendar.YEAR);
    cMonth = c.get(Calendar.MONTH);
    cDay = c.get(Calendar.DAY_OF_MONTH);
    mYear = c.get(Calendar.YEAR);
    mMonth = c.get(Calendar.MONTH);
    mDay = c.get(Calendar.DAY_OF_MONTH);
    cDate = (cDay+"-"+cMonth+"-"+cYear);
    mDate = (mDay+"-"+mMonth+"-"+mYear); 
    Date past = new Date(112, cMonth, cDay); // current Date
    Date today = new Date(112, 11, 18); // date Choosen by the user
    final int days = Days.daysBetween(new DateTime(past), new DateTime(today)).getDays()+1;
     cDateDisplay.setText(cDate);

     //display the current date (this method is below)
     updateDisplay();

    mButton = (Button)findViewById(R.id.get);
    cweight   = (EditText)findViewById(R.id.cweight);
    nweight   = (EditText)findViewById(R.id.nweight);
    t = (TextView)findViewById(R.id.out);

    mButton.setOnClickListener(
        new View.OnClickListener()
        {
            public void onClick(View view)
            {
                db.open();
                while(cweight != null && nweight  != null);
                {
                    s = WorkoutChoice.this.cweight.getText().toString();
                    current =  Integer.parseInt(s);
                    s2 = WorkoutChoice.this.nweight.getText().toString();
                    target =  Integer.parseInt(s2);
                    db.deleteFirst();
                    db.insertTitle(mDate, current, target);
                    CharSequence text = "Goal Set\n"+"Target Date"+mDate+"\n"+"Current Weight "+current+"\n"+"Target Weight "+target;
                    Toast toast = Toast.makeText(context, text, duration);
                    toast.show();
                    /*Intent i = new Intent();
                    i.setClassName("com.b00348312.workout","com.b00348312.workout.WorkoutMenu");
                    startActivity(i);*/
                }
               db.close(); 
            }
        });

}
public void convert(View view) 
{
    Intent i = new Intent();
    i.setClassName("com.b00348312.workout","com.b00348312.workout.convert");
    startActivity(i); 
}
 private void updateDisplay() {
        mDateDisplay.setText(
            new StringBuilder()
                    // Month is 0 based so add 1
                    .append(mDay).append("-")
                    .append(mMonth + 1).append("-")
                    .append(mYear).append(" "));
        /*cDateDisplay.setText(
                new StringBuilder()
                        // Month is 0 based so add 1
                        .append(cDay).append("-")
                        .append(cMonth + 1).append("-")
                        .append(cYear).append(" "));*/
    } 
 private DatePickerDialog.OnDateSetListener mDateSetListener =
            new DatePickerDialog.OnDateSetListener() {

                public void onDateSet(DatePicker view, int year, 
                                      int monthOfYear, int dayOfMonth) {
                    mYear = year;
                    mMonth = monthOfYear;
                    mDay = dayOfMonth;
                    updateDisplay();
                }
            };
           @Override
           protected Dialog onCreateDialog(int id) {
                switch (id) {
                case DATE_DIALOG_ID:
                    return new DatePickerDialog(this,
                                mDateSetListener,
                                mYear, mMonth, mDay);
                }
                return null;
            }
}
<?xml version="1.0" encoding="utf-8"?>

<TextView
    android:id="@+id/Cdate"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Current Date"
    android:textAppearance="?android:attr/textAppearanceSmall" android:textColor="#000000"/>

<TextView
    android:id="@+id/Current"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text=""
    android:textAppearance="?android:attr/textAppearanceMedium" android:textColor="#000000"/>

<TextView
    android:id="@+id/blank"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Target"
    android:textColor="#000000" />
<TextView
    android:id="@+id/dateDisplay"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text=""
    android:textAppearance="?android:attr/textAppearanceMedium" android:textColor="#000000"/>
<Button
    android:id="@+id/pickDate"
    android:layout_width="324dp"
    android:layout_height="wrap_content"
    android:text="Change the date"/>
<TextView
     android:text="Enter Enter Current Weight (Kg)" 
     android:layout_height="wrap_content" 
     android:layout_width="wrap_content" 
     android:textAppearance="?android:attr/textAppearanceLarge" android:textColor="#00000F">
</TextView>
<EditText
    android:id="@+id/cweight"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:inputType="numberDecimal" >
        <requestFocus></requestFocus>
</EditText>
<TextView android:text="Enter Desired Weight(kg)" 
    android:id="@+id/textView1" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" android:textStyle="bold" android:textColor="#00000F"></TextView>

<EditText
    android:id="@+id/nweight"
    android:layout_width="320dp"
    android:layout_height="wrap_content"
    android:inputType="numberDecimal" >

Answer 1

Your code is in an infinite loop.

Change: while(cweight != null && nweight != null);

To: if(cweight != null && nweight != null);

One other thing: Are you sure you want to check for null here. I would check that the values are appropriate here before querying the database. I doubt they would ever be null. (there would be other errors)

Answer 2

Do onclick work in non UI thread like using Asycn task or create other thread and use handler as here it is db work and may be time consuming...