What is the departure betwixt include together with forrard methods of RequestDispatcher interface is 1 of the frequently asked Servlet questions from Java EE interviews together with we'll run into how yous tin reply this inquiry on your interview. You larn the RequestDispatcher reference either from ServletContext or ServletRequest interface together with fifty-fifty though both include() together with forward() method allow a Servlet to interact amongst closed to other servlet, primary departure betwixt include() together with forward is that include() method is used to charge the contents of the specified resources (could locomote a Servlet, JSP, or static resources e.g. HTML files) straight into the Servlet's response, equally if it is purpose of the calling Servlet. On the other hand, forward() method is used for server side redirection, where an HTTP asking for 1 servlet is routed to closed to other resources (Servlet, JSP file or HTML file) for processing.
This inquiry is often asked equally a follow-up of to a greater extent than pop Servlet Question, the difference betwixt forward() together with sendRedirect() inwards Servlet. Now, nosotros know the key departure betwixt these 2 methods, let's run into a twain of to a greater extent than differences to reply this inquiry a fiddling chip better.
Just recollect that, fifty-fifty though yous tin larn the RequestDispatcher reference from ServletContext.getRequestDispatcher() method or ServletRequest.getRequestDispatcher() method only at that topographic point is a slight difference, the pathname of Servlet must get amongst a / and is interpreted equally relative to the electrical flow context root, piece inwards illustration of ServletRequest, path tin locomote relative.
Btw, if yous are preparing for Java spider web or Java EE developer interview, yous tin likewise run into the Java Programming Interview exposed for to a greater extent than questions on Servlet, JSP, Spring, together with Hibernate, key skills for Java spider web developers.
1) Both include() together with forward() methods are purpose of RequestDispatcher interface of Servlet API
2) Both methods stimulate got objects of ServletRequest together with ServletResponse interface.
3) Both include() together with forward() tin interact amongst static together with dynamic resources e.g. closed to other Servlet, JSP or HTML files.
Now, let's run into twain of differences betwixt include together with forward() method from Servlet API:
1) First together with inaugural departure is that include() method includes the content of a resources inwards the response, the resources could locomote closed to other Servlet, JSP or HTML file. While forward() method is used to forrard the asking to closed to other resource.
2) The minute departure betwixt include() together with forward() from Servlet API is that If yous include a servlet or JSP document, the included resources must non endeavor to alter the response condition code or HTTP headers, whatever such asking volition locomote ignored. On the other hand, If yous include a Servlet or JSP document, the included resources must non endeavor to alter the response condition code or HTTP headers, whatever such asking volition locomote ignored.
3) Third together with a useful departure betwixt forward() together with include() method is that quondam is often used to include mutual boilerplate text of template markup which mightiness locomote included yesteryear many Servlets e.g. header or footer. While, forward() method is often used where a servlet is taking a controller role; processing closed to input together with deciding the number yesteryear returning a item response page.
Here are 2 diagrams which volition help yous sympathize how both include together with forrard methods of RequestDispatcher works inwards Servlet application:
How include method of RequestDispatcher works
You tin run into that the asking is for DispatcherServlet which calls include() method to include the response of Hello.jsp page, afterwards the response of DispatcherServlet together with Hello.jsp is combined together with sent to the client.
How forrard method of RequestDispatcher works
You tin run into the asking is for Servlet1 which forwards it to Servlet2, whose response is together with hence sent to the client. The response of Servlet1 is non used or non sent to the client.
That's all virtually the difference betwixt include() together with forward() inwards Servlet API. You should usage include() method to charge a resources which could locomote a JSP page or closed to other Servlet, together with usage forward() to redirect the asking to closed to other resources for farther processing, 1 time to a greater extent than yous tin forrard the asking to closed to other Servlet or JSP page.
Related Servlet together with JSP interview questions for Java programmers
Further Learning
Java Web Fundamentals By Kevin Jones
Spring Framework 5: Beginner to Guru
JSP, Servlets together with JDBC for Beginners: Build a Database App
This inquiry is often asked equally a follow-up of to a greater extent than pop Servlet Question, the difference betwixt forward() together with sendRedirect() inwards Servlet. Now, nosotros know the key departure betwixt these 2 methods, let's run into a twain of to a greater extent than differences to reply this inquiry a fiddling chip better.
Just recollect that, fifty-fifty though yous tin larn the RequestDispatcher reference from ServletContext.getRequestDispatcher() method or ServletRequest.getRequestDispatcher() method only at that topographic point is a slight difference, the pathname of Servlet must get amongst a / and is interpreted equally relative to the electrical flow context root, piece inwards illustration of ServletRequest, path tin locomote relative.
Btw, if yous are preparing for Java spider web or Java EE developer interview, yous tin likewise run into the Java Programming Interview exposed for to a greater extent than questions on Servlet, JSP, Spring, together with Hibernate, key skills for Java spider web developers.
include() vs forrard inwards Servlet
Before looking at the differences betwixt include() together with forward() method inwards Servlet, let's run into closed to similarities betwixt them.1) Both include() together with forward() methods are purpose of RequestDispatcher interface of Servlet API
2) Both methods stimulate got objects of ServletRequest together with ServletResponse interface.
3) Both include() together with forward() tin interact amongst static together with dynamic resources e.g. closed to other Servlet, JSP or HTML files.
Now, let's run into twain of differences betwixt include together with forward() method from Servlet API:
1) First together with inaugural departure is that include() method includes the content of a resources inwards the response, the resources could locomote closed to other Servlet, JSP or HTML file. While forward() method is used to forrard the asking to closed to other resource.
2) The minute departure betwixt include() together with forward() from Servlet API is that If yous include a servlet or JSP document, the included resources must non endeavor to alter the response condition code or HTTP headers, whatever such asking volition locomote ignored. On the other hand, If yous include a Servlet or JSP document, the included resources must non endeavor to alter the response condition code or HTTP headers, whatever such asking volition locomote ignored.
3) Third together with a useful departure betwixt forward() together with include() method is that quondam is often used to include mutual boilerplate text of template markup which mightiness locomote included yesteryear many Servlets e.g. header or footer. While, forward() method is often used where a servlet is taking a controller role; processing closed to input together with deciding the number yesteryear returning a item response page.
Here are 2 diagrams which volition help yous sympathize how both include together with forrard methods of RequestDispatcher works inwards Servlet application:
How include method of RequestDispatcher works
You tin run into that the asking is for DispatcherServlet which calls include() method to include the response of Hello.jsp page, afterwards the response of DispatcherServlet together with Hello.jsp is combined together with sent to the client.
How forrard method of RequestDispatcher works
You tin run into the asking is for Servlet1 which forwards it to Servlet2, whose response is together with hence sent to the client. The response of Servlet1 is non used or non sent to the client.
That's all virtually the difference betwixt include() together with forward() inwards Servlet API. You should usage include() method to charge a resources which could locomote a JSP page or closed to other Servlet, together with usage forward() to redirect the asking to closed to other resources for farther processing, 1 time to a greater extent than yous tin forrard the asking to closed to other Servlet or JSP page.
Related Servlet together with JSP interview questions for Java programmers
- Difference betwixt ServletContext together with ServletConfig inwards Servlet? (answer)
- Can yous declare Constructor within Servlet class? (answer)
- Difference betwixt GenericServlet together with HttpServlet inwards Servlet API? (answer)
- Difference betwixt the spider web server, application server together with Servlet container? (answer)
- How to grapple customer session inwards Servlet application? (answer)
- Difference betwixt include directive together with include activity inwards JSP? (answer)
- Difference betwixt jsp:include together with jsp:forward activity inwards JSP? (answer)
Further Learning
Java Web Fundamentals By Kevin Jones
Spring Framework 5: Beginner to Guru
JSP, Servlets together with JDBC for Beginners: Build a Database App
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