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Posted to users@wicket.apache.org by kumar ramanathan <ku...@gmail.com> on 2014/06/27 06:33:51 UTC

how to handle null pointer exception while submit button

Hi Friends,
I have a text box and a submit button , If i pressed submit button without
entering anything in textbox , am getting null pointer exception . Can you
please help us on it ?


Thanks,
Kumar 

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Re: how to handle null pointer exception while submit button

Posted by Mihir Chhaya <mi...@gmail.com>.
Hmmm...then that leaves a question open on my side that why I didn't get
NPE with that code?
One more thing I observed and you might have already taken care of in your
actual code, but any reason not writing generics type
TextField<Type>/Model<Type> etc in your component?

-Mihir.


On Fri, Jun 27, 2014 at 10:51 PM, kumar ramanathan <kumarramanatha@gmail.com
> wrote:

> Thanks for reviewing the issue.I have actually fixed my problem.I have used
> setconvertemptyinputstrngtonull method.
>
>                 TextField memberIdField = new
> TextField("memberId",memberIdModel);
>                 *memberIdField.setConvertEmptyInputStringToNull(false);*
>                 TextField lossIdField = new
> TextField("lossId",lossIdModel);
>                 lossIdField.setConvertEmptyInputStringToNull(false);
>
>
> --
> View this message in context:
> http://apache-wicket.1842946.n4.nabble.com/how-to-handle-null-pointer-exception-while-submit-button-tp4666392p4666404.html
> Sent from the Users forum mailing list archive at Nabble.com.
>
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Re: how to handle null pointer exception while submit button

Posted by kumar ramanathan <ku...@gmail.com>.
Thanks for reviewing the issue.I have actually fixed my problem.I have used
setconvertemptyinputstrngtonull method.

                TextField memberIdField = new
TextField("memberId",memberIdModel);
		*memberIdField.setConvertEmptyInputStringToNull(false);*
		TextField lossIdField = new TextField("lossId",lossIdModel);
		lossIdField.setConvertEmptyInputStringToNull(false);


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Re: how to handle null pointer exception while submit button

Posted by Mihir Chhaya <mi...@gmail.com>.
Kumar,

I ran following (copied from your code) and it is showing me the value for
memberNumber. No NPE. Since you have String as memberID, I have assigned
String type to the models and property variable.


PropertyModel<String> memberIdModel=new
PropertyModel<String>(this,"memberNumber");
        TextField<String> memberIdField = new
TextField<String>("memberId",memberIdModel);


Form<?> form = new Form<Void>("form"){
 /**
 *
 */
private static final long serialVersionUID = 1L;

/* (non-Javadoc)
 * @see org.apache.wicket.markup.html.form.Form#onSubmit()
 */
@Override
protected void onSubmit() {
 System.out.println(memberNumber.equals("5566"));
}
};
add(form);

As Sven has mentioned, stacktrace might be more helpful.




On Fri, Jun 27, 2014 at 6:16 AM, kumar ramanathan <ku...@gmail.com>
wrote:

>
>         PropertyModel memberIdModel=new PropertyModel(this,"memberNumber");
>         PropertyModel lossIdModel=new PropertyModel(this,"lossNumber");
>         TextField memberIdField = new TextField("memberId",memberIdModel);
>         TextField lossIdField = new TextField("lossId",lossIdModel);
>
> Form form=new Form("form1"){
>             public void onSubmit(){
>
>
>                 flag=0;
>                 assignments.clear();
>                 estimates.clear();
>                 assignments.add(new
> AssignmentDB("MemberId","LossId","AssignemntId","DOL"));
>                 assignments.add(new
> AssignmentDB("1234","001","1357","10/12/1067"));
>                 assignments.add(new
> AssignmentDB("1234","001","1358","10/12/1067"));
>                 assignments.add(new
> AssignmentDB("1234","003","1357","10/12/1067"));
>
>                 for(int i=1;i<assignments.size();){
>
> if(memberNumber.equals(assignments.get(i).getMemberId())){
>                         System.out.println("inside2");
>
> if(lossNumber.equals(assignments.get(i).getLossId())){
>                             System.out.println("inside3");
>                             i=i+1;
>                         }
>                         else{
>                             assignments.remove(i);
>                             i=1;
>                         }
>
>                     }
>                     else{
>                         assignments.remove(i);
>                         i=1;
>                     }
>
>                 }
>                 if(assignments.size()<=1){
>
>                     setAsssignmentLabel("Assignments Output");
>                     assignments.clear();
>                     setAsssignmentResult("No Assignments for the given
> member number and loss number");
>                     setEstimateResult("");
>                     setEstimateLabel("");
>                 }
>                 else{
>                     setAsssignmentLabel("Assignments Ouput");
>
>                     setAsssignmentResult("");
>                     setEstimateResult("");
>                 }
>               }//form submit
>
>
>              };//form
>
>         form.add(memberIdField);
>         form.add(lossIdField);
>         add(form);
>
>
> This is my code snippet . Kindly help me.
>
> --
> View this message in context:
> http://apache-wicket.1842946.n4.nabble.com/how-to-handle-null-pointer-exception-while-submit-button-tp4666392p4666396.html
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>
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Re: how to handle null pointer exception while submit button

Posted by kumar ramanathan <ku...@gmail.com>.
        
        PropertyModel memberIdModel=new PropertyModel(this,"memberNumber");
        PropertyModel lossIdModel=new PropertyModel(this,"lossNumber");
        TextField memberIdField = new TextField("memberId",memberIdModel);
        TextField lossIdField = new TextField("lossId",lossIdModel);

Form form=new Form("form1"){
            public void onSubmit(){
                
                
                flag=0;
                assignments.clear();
                estimates.clear();
                assignments.add(new
AssignmentDB("MemberId","LossId","AssignemntId","DOL"));
                assignments.add(new
AssignmentDB("1234","001","1357","10/12/1067"));
                assignments.add(new
AssignmentDB("1234","001","1358","10/12/1067"));
                assignments.add(new
AssignmentDB("1234","003","1357","10/12/1067"));
               
                for(int i=1;i<assignments.size();){
                   
if(memberNumber.equals(assignments.get(i).getMemberId())){
                        System.out.println("inside2");
                       
if(lossNumber.equals(assignments.get(i).getLossId())){
                            System.out.println("inside3");
                            i=i+1;
                        }
                        else{
                            assignments.remove(i);
                            i=1;
                        }
                            
                    }
                    else{
                        assignments.remove(i);
                        i=1;
                    }
                        
                }      
                if(assignments.size()<=1){
                    
                    setAsssignmentLabel("Assignments Output");
                    assignments.clear();
                    setAsssignmentResult("No Assignments for the given
member number and loss number");
                    setEstimateResult("");
                    setEstimateLabel("");
                }
                else{
                    setAsssignmentLabel("Assignments Ouput");
                  
                    setAsssignmentResult("");
                    setEstimateResult("");
                }
              }//form submit
        
                    
             };//form    
        
        form.add(memberIdField);
        form.add(lossIdField);
        add(form);
       

This is my code snippet . Kindly help me.

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Re: how to handle null pointer exception while submit button

Posted by Mihir Chhaya <mi...@gmail.com>.
Can you share your code snippet? Which type of model are you using?


On Fri, Jun 27, 2014 at 1:17 AM, Sven Meier <sv...@meiers.net> wrote:

> #setConvertEmptyInputStringToNull(false) could help, but with a
> stacktrace we can give you a better advice.
>
> Sven
>
>
> On 06/27/2014 06:33 AM, kumar ramanathan wrote:
>
>> Hi Friends,
>> I have a text box and a submit button , If i pressed submit button without
>> entering anything in textbox , am getting null pointer exception . Can you
>> please help us on it ?
>>
>>
>> Thanks,
>> Kumar
>>
>> --
>> View this message in context: http://apache-wicket.1842946.
>> n4.nabble.com/how-to-handle-null-pointer-exception-while-
>> submit-button-tp4666392.html
>> Sent from the Users forum mailing list archive at Nabble.com.
>>
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
>> For additional commands, e-mail: users-help@wicket.apache.org
>>
>>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
> For additional commands, e-mail: users-help@wicket.apache.org
>
>

Re: how to handle null pointer exception while submit button

Posted by Sven Meier <sv...@meiers.net>.
#setConvertEmptyInputStringToNull(false) could help, but with a 
stacktrace we can give you a better advice.

Sven

On 06/27/2014 06:33 AM, kumar ramanathan wrote:
> Hi Friends,
> I have a text box and a submit button , If i pressed submit button without
> entering anything in textbox , am getting null pointer exception . Can you
> please help us on it ?
>
>
> Thanks,
> Kumar
>
> --
> View this message in context: http://apache-wicket.1842946.n4.nabble.com/how-to-handle-null-pointer-exception-while-submit-button-tp4666392.html
> Sent from the Users forum mailing list archive at Nabble.com.
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe@wicket.apache.org
> For additional commands, e-mail: users-help@wicket.apache.org
>


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Re: how to handle null pointer exception while submit button

Posted by Paul Bors <pa...@bors.ws>.
Must be the wrong mailing list, ignore :)

On Sun, Oct 5, 2014 at 11:15 PM, Warren Bell <wa...@clarksnutrition.com>
wrote:

> OK, a little confused, AWT, Applet ? Is Wicket up to something I haven’t
> heard about ?
>
> Warren
>
> On Oct 5, 2014, at 7:57 PM, Taught by S&M <qa...@gmail.com>
> wrote:
>
> > This code will help to handle exceptions when there is a single
> TextField:
> >
> > import java.awt.*;
> > import java.awt.event.*;
> > import java.applet.*;
> >
> > /*
> > <applet code="throwsDemo.class" height=250 width=300>
> > </applet>
> > */
> >
> > class FieldZeroException extends Exception
> > {
> >       FieldZeroException()
> >       {
> >       }
> >
> >       public String toString()
> >       {
> >       return "Text field is empty.";
> >       }
> > }
> >
> > public class throwsDemo extends Applet implements ActionListener
> > {
> > Button b1;
> > TextField tf1,tf2;
> > Label l1,l2;
> >
> >       public void init()
> >       {
> >       setLayout(new FlowLayout(FlowLayout.LEFT));
> >       l1=new Label("NULL");
> >       l1.setForeground(Color.RED);
> >       l2=new Label();
> >       l2.setForeground(Color.GREEN);
> >       tf1=new TextField(10);
> >       b1=new Button("Check");
> >       add(tf1);
> >       add(b1);
> >       add(l1);
> >       add(l2);
> >       b1.addActionListener(this);
> >       }
> >
> >       public void actionPerformed(ActionEvent ae)
> >       {
> >               if(ae.getSource()==b1)
> >               {
> >               String str1=tf1.getText();
> >               int i=str1.length();
> >                       try
> >                       {
> >                               if(i==0)
> >                               {
> >                               throw new FieldZeroException();
> >                               }
> >                               else
> >                               {
> >                               l1.setText("Success");
> >                               }
> >                       }
> >                       catch(FieldZeroException fze)
> >                       {
> >                       l1.setText(fze.toString());
> >                       }
> >               }
> >       }
> > }
> >
> > --
> > View this message in context:
> http://apache-wicket.1842946.n4.nabble.com/how-to-handle-null-pointer-exception-while-submit-button-tp4666392p4667826.html
> > Sent from the Users forum mailing list archive at Nabble.com.
> >
> > ---------------------------------------------------------------------
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> >
> >
> > --
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> Gateway.
>
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Re: how to handle null pointer exception while submit button

Posted by Warren Bell <wa...@clarksnutrition.com>.
OK, a little confused, AWT, Applet ? Is Wicket up to something I haven’t heard about ?

Warren

On Oct 5, 2014, at 7:57 PM, Taught by S&M <qa...@gmail.com> wrote:

> This code will help to handle exceptions when there is a single TextField:
> 
> import java.awt.*;
> import java.awt.event.*;
> import java.applet.*;
> 
> /*
> <applet code="throwsDemo.class" height=250 width=300>
> </applet>
> */
> 
> class FieldZeroException extends Exception
> {
> 	FieldZeroException()
> 	{
> 	}
> 	
> 	public String toString()
> 	{
> 	return "Text field is empty.";
> 	}
> }
> 
> public class throwsDemo extends Applet implements ActionListener
> {
> Button b1;
> TextField tf1,tf2;
> Label l1,l2;
> 
> 	public void init()
> 	{
> 	setLayout(new FlowLayout(FlowLayout.LEFT));
> 	l1=new Label("NULL");
> 	l1.setForeground(Color.RED);
> 	l2=new Label();
> 	l2.setForeground(Color.GREEN);
> 	tf1=new TextField(10);
> 	b1=new Button("Check");
> 	add(tf1);
> 	add(b1);
> 	add(l1);
> 	add(l2);
> 	b1.addActionListener(this);
> 	}
> 	
> 	public void actionPerformed(ActionEvent ae)
> 	{
> 		if(ae.getSource()==b1)
> 		{
> 		String str1=tf1.getText();
> 		int i=str1.length();
> 			try
> 			{
> 				if(i==0)
> 				{
> 				throw new FieldZeroException();
> 				}
> 				else
> 				{
> 				l1.setText("Success");
> 				}
> 			}
> 			catch(FieldZeroException fze)
> 			{
> 			l1.setText(fze.toString());
> 			}
> 		}
> 	}
> }
> 
> --
> View this message in context: http://apache-wicket.1842946.n4.nabble.com/how-to-handle-null-pointer-exception-while-submit-button-tp4666392p4667826.html
> Sent from the Users forum mailing list archive at Nabble.com.
> 
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> 
> 
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> This email was Virus checked by Clark's Nutrition's Astaro Security Gateway.


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Re: how to handle null pointer exception while submit button

Posted by Taught by S&M <qa...@gmail.com>.
This code will help to handle exceptions when there is a single TextField:

import java.awt.*;
import java.awt.event.*;
import java.applet.*;

/*
<applet code="throwsDemo.class" height=250 width=300>
</applet>
*/

class FieldZeroException extends Exception
{
	FieldZeroException()
	{
	}
	
	public String toString()
	{
	return "Text field is empty.";
	}
}

public class throwsDemo extends Applet implements ActionListener
{
Button b1;
TextField tf1,tf2;
Label l1,l2;

	public void init()
	{
	setLayout(new FlowLayout(FlowLayout.LEFT));
	l1=new Label("NULL");
	l1.setForeground(Color.RED);
	l2=new Label();
	l2.setForeground(Color.GREEN);
	tf1=new TextField(10);
	b1=new Button("Check");
	add(tf1);
	add(b1);
	add(l1);
	add(l2);
	b1.addActionListener(this);
	}
	
	public void actionPerformed(ActionEvent ae)
	{
		if(ae.getSource()==b1)
		{
		String str1=tf1.getText();
		int i=str1.length();
			try
			{
				if(i==0)
				{
				throw new FieldZeroException();
				}
				else
				{
				l1.setText("Success");
				}
			}
			catch(FieldZeroException fze)
			{
			l1.setText(fze.toString());
			}
		}
	}
}

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