Howto: call a Servlet from another Servlet (Example)?!
Hello, I have create two Servlets (LoginServlet UserListServlet). I'm using a JSP for the User credentials. When you press the login-button, the LoginServlet is called. I would like to call the UserListServlet, when the username and password are correct. How can I call UserListServle from the doGet(...) function of the LoginServlet. I would like to call a Servlet from another servlet. Where can I find some examples? Thanks, Michael
Re: Howto: call a Servlet from another Servlet (Example)?!
- Original Message - From: Michael Stockhausen prof.dr.moe...@googlemail.com I have create two Servlets (LoginServlet UserListServlet). I'm using a JSP for the User credentials. When you press the login-button, the LoginServlet is called. I would like to call the UserListServlet, when the username and password are correct. Where can I find some examples? Thanks, Michael I teach this in my Graphical User Interface Programming class: (http://www.wiu.edu/users/mflll/CS412g/n3x.xml.pdf) URL url = new URL(http://toolman.wiu.edu:14096/servlet/OurData;); InputStream openStream = url.openStream(); InputStreamReader r = new InputStreamReader(openStream); char buf[] = new char[1]; r.read(buf,0,1); One just starts the servlet by invoking it with a URL and reading from the stream. I may have seen this in the Servlet Programming by Jason Hunter and William Crawford. Dr. Laurence Leff Western Illinois University, Macomb IL 61455 ||(309) 298-1315 Stipes 447 Assoc. Prof. of Computer Sci. Pager: 309-367-0787 FAX: 309-298-2302 - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Howto: call a Servlet from another Servlet (Example)?!
You can use the RequestDispatcher. RequestDispatcher dispatcher = request.getRequestDispatcher(/userlist); dispatcher.forward(request, response); Google gives you a lot of examples. Ronald. Op maandag, 20 september 2010 16:47 schreef Michael Stockhausen prof.dr.moe...@googlemail.com: Hello, I have create two Servlets (LoginServlet UserListServlet). I'm using a JSP for the User credentials. When you press the login-button, the LoginServlet is called. I would like to call the UserListServlet, when the username and password are correct. How can I call UserListServle from the doGet(...) function of the LoginServlet. I would like to call a Servlet from another servlet. Where can I find some examples? Thanks, Michael
Re: Howto: call a Servlet from another Servlet (Example)?!
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Ronald, On 9/20/2010 11:07 AM, Ronald Klop wrote: You can use the RequestDispatcher. RequestDispatcher dispatcher = request.getRequestDispatcher(/userlist); dispatcher.forward(request, response); Of course, you can also issue a redirect to the client: response.sendRedirect(...) The advantage of issuing a redirect is that the client will not have to re-authenticate if the user then RELOADs the resulting page. - -chris -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.10 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAkyXf3gACgkQ9CaO5/Lv0PDRmQCfSKPGx2EbXA8dA0WlcbNee8M9 /YYAoJ6iHtoM5pYzteMy3DMHzH07OCno =bBF7 -END PGP SIGNATURE- - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
RE: Howto: call a Servlet from another Servlet (Example)?!
-Original Message- From: Christopher Schultz [mailto:ch...@christopherschultz.net] Subject: Re: Howto: call a Servlet from another Servlet (Example)?! -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Ronald, On 9/20/2010 11:07 AM, Ronald Klop wrote: You can use the RequestDispatcher. RequestDispatcher dispatcher = request.getRequestDispatcher(/userlist); dispatcher.forward(request, response); Of course, you can also issue a redirect to the client: response.sendRedirect(...) The advantage of issuing a redirect is that the client will not have to re-authenticate if the user then RELOADs the resulting page. - -chris -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.10 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAkyXf3gACgkQ9CaO5/Lv0PDRmQCfSKPGx2EbXA8dA0WlcbNee8M9 /YYAoJ6iHtoM5pYzteMy3DMHzH07OCno =bBF7 -END PGP SIGNATURE- I thought that if you were making a request to a UserListServlet and it was restricted to authentication, assuming you use Form Authentication and structure your login form correctly, you don't have to worry about calling LoginServlet or using the requestDispatcher? Doesn't Tomcat handle this for you? What am I missing here? In the OP question, to what does the LoginServlet authenticate you? The LoginServlet?
Re: Howto: call a Servlet from another Servlet (Example)?!
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Leo, On 9/20/2010 12:55 PM, Leo Donahue - PLANDEVX wrote: I thought that if you were making a request to a UserListServlet and it was restricted to authentication, assuming you use Form Authentication and structure your login form correctly, you don't have to worry about calling LoginServlet or using the requestDispatcher? Doesn't Tomcat handle this for you? What am I missing here? In the OP question, to what does the LoginServlet authenticate you? The LoginServlet? - From my reading, the OP is doing his own authentication rather than using container-managed authentication. If he /is/ using container-managed authentication, then he's using it incorrectly :) - -chris -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.10 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAkyXpakACgkQ9CaO5/Lv0PCQ1QCginz5lDgSDCX/U6ek3oEQXvgg pdwAoKP12wnSztLoujxoj7rvNY8N4u/3 =r7fJ -END PGP SIGNATURE- - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
RE: Howto: call a Servlet from another Servlet (Example)?!
Chris, -Original Message- From: Christopher Schultz [mailto:ch...@christopherschultz.net] Subject: Re: Howto: call a Servlet from another Servlet (Example)?! -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 - From my reading, the OP is doing his own authentication rather than using container-managed authentication. - -chris -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.10 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAkyXpakACgkQ9CaO5/Lv0PCQ1QCginz5lDgSDCX/U6ek3oEQXvgg pdwAoKP12wnSztLoujxoj7rvNY8N4u/3 =r7fJ -END PGP SIGNATURE- I thought rolling your own authentication, rather than using container-managed security for authentication, is a bad idea? Is that just rhetoric?
Re: Howto: call a Servlet from another Servlet (Example)?!
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Leo, On 9/20/2010 3:05 PM, Leo Donahue - PLANDEVX wrote: Chris, -Original Message- From: Christopher Schultz [mailto:ch...@christopherschultz.net] Subject: Re: Howto: call a Servlet from another Servlet (Example)?! - From my reading, the OP is doing his own authentication rather than using container-managed authentication. -chris I thought rolling your own authentication, rather than using container-managed security for authentication, is a bad idea? Is that just rhetoric? That's a matter of perspective. I'd recommend using container-managed authentication and authorization to pretty much everybody. Or, failing that, at least use a library meant for doing such things, like ACEGI or securityfilter: the folks in charge of those projects have taken care to be spec-compliant (to the extent possible and/or desired) and properly test their products to ensure that they are safe. Rolling your own authentication mechanism often leads to an insecure system. It's also usually not necessary: container-managed security works very well for most people, and the new servlet 3.0 changes to authentication even (I believe) allow the webapp to request authentication under certain other circumstances. - -chris -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.10 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAkyXt/QACgkQ9CaO5/Lv0PBbEgCffmnSHPKJ12KCZmspuv0CdcWY H5gAoLm4Yrwym1elDFvmFs+y0yta6+8P =no35 -END PGP SIGNATURE- - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Howto: call a Servlet from another Servlet (Example)?!
On 20/09/2010 16:00, Laurence L Leff wrote: - Original Message - From: Michael Stockhausen prof.dr.moe...@googlemail.com I have create two Servlets (LoginServlet UserListServlet). I'm using a JSP for the User credentials. When you press the login-button, the LoginServlet is called. I would like to call the UserListServlet, when the username and password are correct. Where can I find some examples? Thanks, Michael I teach this in my Graphical User Interface Programming class: (http://www.wiu.edu/users/mflll/CS412g/n3x.xml.pdf) URL url = new URL(http://toolman.wiu.edu:14096/servlet/OurData;); InputStream openStream = url.openStream(); InputStreamReader r = new InputStreamReader(openStream); char buf[] = new char[1]; r.read(buf,0,1); One just starts the servlet by invoking it with a URL and reading from the stream. Ermm... I'm not really sure that's what he's looking for. p 0x62590808.asc Description: application/pgp-keys signature.asc Description: OpenPGP digital signature
RE: Howto: call a Servlet from another Servlet (Example)?!
-Original Message- From: Leo Donahue - PLANDEVX [mailto:leodona...@mail.maricopa.gov] Sent: Monday, September 20, 2010 10:56 AM To: 'Tomcat Users List' Subject: RE: Howto: call a Servlet from another Servlet (Example)?! -Original Message- From: Christopher Schultz [mailto:ch...@christopherschultz.net] Subject: Re: Howto: call a Servlet from another Servlet (Example)?! -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Ronald, On 9/20/2010 11:07 AM, Ronald Klop wrote: You can use the RequestDispatcher. RequestDispatcher dispatcher = request.getRequestDispatcher(/userlist); dispatcher.forward(request, response); Of course, you can also issue a redirect to the client: response.sendRedirect(...) Please make sure that any examples of respond.sendRedirect() or RequestDispatcher.forward() are IMMEDIATELY followed by a return statement because neither of those statements terminates the calling servlet's processing. IOW, processing chugs right along. This can cause very strange problems. It can also expose potential security problems because often you're redirecting to a login page. If you don't terminate processing, the code further along can assume the user is authenticated. The advantage of issuing a redirect is that the client will not have to re-authenticate if the user then RELOADs the resulting page. - -chris -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.10 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAkyXf3gACgkQ9CaO5/Lv0PDRmQCfSKPGx2EbXA8dA0WlcbNee8M9 /YYAoJ6iHtoM5pYzteMy3DMHzH07OCno =bBF7 -END PGP SIGNATURE- I thought that if you were making a request to a UserListServlet and it was restricted to authentication, assuming you use Form Authentication and structure your login form correctly, you don't have to worry about calling LoginServlet or using the requestDispatcher? Doesn't Tomcat handle this for you? What am I missing here? In the OP question, to what does the LoginServlet authenticate you? The LoginServlet? George Sexton MH Software, Inc. 303 438-9585 www.mhsoftware.com - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
