Exception handling in JSP

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Exception handling is a mechanism to handle runtime errors so that normal flow of the program can be maintained.

 

Ways of exception handling in JSP:

  1. Using page directive (errorPage and isErrorPage attributes).
  2. Using <error-page> attribute of web.xml.

 

Exception handling example using errorPage and isErrorPage attributes:

welcome.jsp

<%@ page errorPage="errorPage.jsp" %>  
 
<html>
    <head>
      <title>isErrorPage and errorPage page directive example</title>
    </head>
    <body>
        <%= 0/0 %>
    </body>
</html>

 

errorPage.jsp

<%@ page isErrorPage="true" %>  
 
<html>
    <head>
      <title>isErrorPage and errorPage page directive example</title>
    </head>
    <body>
               	<h3>Hello this is an isErrorPage and 
                    errorPage page directive example.</h3>
        <br/>
        <h3>Some exception occurred.</h3>
        Exception: <%=exception %>
    </body>
</html>

 

web.xml

<web-app>
 
  <welcome-file-list>
          <welcome-file>welcome.jsp</welcome-file>
  </welcome-file-list>	
 
</web-app>

 

Exception handling example using <error-page> attribute:

welcome.jsp

<html>
    <head>
        <title>Exception handling example</title>
    </head>
    <body> 
        <%	
            out.print(10/0); 
        %>
    </body>
</html>

 

errorPage.jsp

<%@ page isErrorPage="true" %>
 
<html>
    <head>
        <title>error page</title>
    </head>
    <body> 
        Occurred exception is: <%= exception %>		
    </body>
</html>

 

web.xml

<web-app>
 
  <error-page>  
  	<exception-type>java.lang.Exception</exception-type>  
  	<location>/error.jsp</location>  
  </error-page> 
 
  <welcome-file-list>
    <welcome-file>welcome.jsp</welcome-file>
  </welcome-file-list>
</web-app>