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error while running my project with tomcat.

 
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I am building project in servlet, jsp,jdbc, in which I want to change my password.here is my servlet code, but when I run this with tomcat , it gives me 500 error given in attachment.
Screenshot_14.png
[Thumbnail for Screenshot_14.png]
this is error when i run my project with tomcat.
 
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It's throwing a nullpointerexception in line 46 of this class. What code do you have in line#46? Line numbers in pasted code and in your editor may not match.
 
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If old/new_password is null then attempting to call the equals method on a null reference will result in a null pointer exception.
You check for null using ==.
 
Marshal
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And you don't check for equality with anything else with ==.
 
Swastik Dey
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May be a method like the following might be helpful

 
Campbell Ritchie
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Swastik Dey wrote:. . . May be a method like the following might be helpful . . .

Maybe useful maybe not. The problem is that you now have two definitions of “empty”, one as in the String class and one here. The two are different; you have a definition of “empty” which includes null. That way lies confusion.
 
sarojni agrwal
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If I remove all the checking part of my code, only updating portion remains, then the code not working means , password is not update in MySQL,why?

 
Swastik Dey
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Are you sure the connection to database is fine, and you are not getting any exception?
 
sarojni agrwal
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No exception this time, and my database connection is fine because, same connection code works on login page and only updation code is change this time, this preaparestmt code is right I think for updating the password, so m not sure why this not working..
 
Swastik Dey
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Make sure Code is going to this block and table name and field names are correct.

if(new_password.equals(confirm_password))
 
sarojni agrwal
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my table in jsp..
 
Swastik Dey
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There seems to be a space in the name attribute

name = " old_password" and the other two fields too. Probably due to this request.getParameter is not fetching the values, and this is a likely reason for nullpointerexception too that you were getting before.
 
sarojni agrwal
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thanku so much swastika.now I am able to update my password.
 
Swastik Dey
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You are most welcome.
 
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