java-servlet: How to call jsp page from a servlet?

Yes, one of the way is RequestDispatcher interface. Following is the sample code to call a jsp from servlet page.

index.jsp :
--------------------
<form action="servlet1" method="post">
Name:<input type="text" name="userName"/><br/>
Password:<input type="password" name="userPass"/><br/>
<input type="submit" value="login"/>
</form>

Login.java :
--------------------
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;


public class Login extends HttpServlet {

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

response.setContentType("text/html");
PrintWriter out = response.getWriter();

String n=request.getParameter("userName");
String p=request.getParameter("userPass");

if(p.equals("servlet"){
RequestDispatcher rd=request.getRequestDispatcher("servlet2");
rd.forward(request, response);
}
else{
out.print("Sorry UserName or Password Error!");
RequestDispatcher rd=request.getRequestDispatcher("/index.jsp");
rd.include(request, response);
}
}

}


WelcomeServlet.java :
---------------------------------
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class WelcomeServlet extends HttpServlet {

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

response.setContentType("text/html");
PrintWriter out = response.getWriter();

String n=request.getParameter("userName");
out.print("Welcome "+n);
}

}


web.xml :
----------------
<web-app>
<servlet>
<servlet-name>Login</servlet-name>
<servlet-class>Login</servlet-class>
</servlet>
<servlet>
<servlet-name>WelcomeServlet</servlet-name>
<servlet-class>WelcomeServlet</servlet-class>
</servlet>


<servlet-mapping>
<servlet-name>Login</servlet-name>
<url-pattern>/servlet1</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>WelcomeServlet</servlet-name>
<url-pattern>/servlet2</url-pattern>
</servlet-mapping>

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

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Second way is you can do it by java script also. But you need to change only in login.java file as

if(p.equals("servlet"){
RequestDispatcher rd=request.getRequestDispatcher("servlet2");
rd.forward(request, response);
}
else{
out.print("<script type=´text/javascript´>window.location.href=´error.jsp´;</script>");
}