I am working on a JSP project. I have a page that calls another JSP.
Now the problem is, how to pass or use a variable in the called JSP page in its calling page?
You can save the variable in the HTTPSession or ServletContext object.
And in the calling JSP page, use or check session attribute for the variable.
session.setAttribute(objectId, Object); to set the variable.
session.getAttribute(objectId); to get the variable.
I have a page that calls another jsp
page
The problem lies here in this sentence.
Try to follow MVC. Use JSP just for rendering the View, and Servlet as a Controller.
Here, simple.souther.us, you find simple and awesome tutorials for newbies.
Your design should be
take one input param on page1.jsp
post it to some servlet , process it there, forward request to page1 jsp and pass param taken from page 1 as attribute
See Also
why-business-logic-should-be-moved-out-of-jsp ?
Related
I am creating a web application in Java. I created some JSP pages each having some form fields. All are post method type so it hides all the form fields. In each page it will call servlet and forward to next JSP page(like a step by step process.)) Welcome page is index.jsp. In the last JSP page also I am having form field which is also post method type. When I press sumbit button, it will call servlet and should forwartd to home page(That is index.jsp).
Last page action value is finish. In my servlet, I am using RequestDispatcher and forwarding to index.jsp. The the URL will be
http://localhost:8080/myproject/finish.
As it is the home page, I wanted to hide that action value. So instead of RequestDispatcher I used
response.sendRedirect("index.jsp"); And then URL becomes
http://localhost:8080/myproject/index.jsp.
This is not a big issue. But still I am asking is there anyway to hide this index.jsp in the URL? It should be like when we open the site for the first time(http://localhost:8080/myproject/).
I got the answer finally. Thanks to #Sayem Ahmed for his reply as comments.
I tried this only
response.sendRedirect("/myproject");
I want to pass parameters from one jsp to another.
I have tried using the post method, <jsp:forward/>, but it doesn't work.
I have created a <form> in html (parameters passed using POST), which is submitted to a servlet which processes the request and forwards it to another servlet that displays a page.
From this servlet i have created links to another jsp, passing through the parameters as GETs in the URL. However, I actually want to pass the parameters to another jsp using POST, and then pass it on to another jsp.
What solutions do you have or this problem?
Check out the Request Dispatcher. You need to forward the request to the landing JSP.
http://docs.oracle.com/javaee/6/api/javax/servlet/RequestDispatcher.html
Sounds like you are creating a multipage form that gathers information from the user across several distinct pages. In that case one option is to use hidden fields on a form to store the previous values. This of course means that as the pages progress the amount of data passing back and forth from client to server increases.
You may consider a server side approach by storing the interim values in a database for instance, then only passing a token back to the client. When the next JSP page is submitted, use the token to look up the values in the database.
JSP has built-in request object.when one jsp redirect to another jsp with some parameter, you can get parameter value using this request object.
<%
String param1 = request.getParameter("parameter_name");
%>
you can find example here -
http://www.roseindia.net/jsp/RequestObjectInJSP.shtml
Why don't you call a page on the click of a submit button by creating
an url in the below format (in javascript):- var
url="your_page_name.jsp?value1="+encodeURIComponent(document.getElementById("your_text_field_or_any_other_field_id"));
and then call the page by using your url
document.your_form_name.action=url;
document.your_form_name.submit();
and then use request.getParameter() method either in servlet
or in the jsp that u'v metioned in the url (servlet or the jsp u'll be
calling thorugh u'r jsp).
I'm using netbeans to create a web application that allows a cell phone user to scan a QR code and retrieve a journal's previous/next title information. The take home point is that there's no form that the user will input data into. The QR code will contain the search string at the end of the URL and I want the search to start on page load and output a page with the search results. For now (due to simplicity), my model is simply parsing an XML file of a small sample of MARC records. Oh, to top it off...I'm brand new to programming in java and using netbeans. I have no clue about what javabeans are, or any of the more advance techniques. So, with that background explanation here's my question.
I have created a java class (main method) that parses my xml and retrieves the results correctly. I have an index.jsp with my html in it. Within the index.jsp, I have no problem using get to get the title information from my URL. But I have no clue how I would get those parameters to a servlet that contains my java code. If I manage to get the search string to the servlet, then I have no idea how to send that data back to the index.jsp to display in the browser.
So far every example I've seen has assumed you're getting form data, but I need parameters found, processed and returned on page load...IOW, with no user input.
Thanks for any advice.
Ceci
Just put the necessary preprocessing code in doGet() method of the servlet:
String foo = request.getParameter("foo");
// ...
request.getRequestDispatcher("/WEB-INF/page.jsp").forward(request, response);
And call the URL of the servlet instead of the JSP one e.g. http://example.com/page?foo=bar instead of http://example.com/page.jsp?foo=bar in combination with a servlet mapping on an URL pattern of /page/*.
You can get the url parameter in servlet using request.getParameter("paramName");
and you can pass the attribute to page from servlet using forwarding request from servlet to jsp.
See Also
Servlet wiki page
Bear in mind that your JSP page will compile internally to a servlet. So you can retrieve the string and print it back in the same JSP. For instance assuming you get the string in a parameter called param you would have something like this in your JSP:
<%
String param = request.getParameter( "param" );
out.println( "String passed in was " + param );
%>
One last thing, you mentioned the main method -- that only gets executed for stand alone applications -- whereas you're talking web/JSP :O
I need to call from one JSP to another, do some stuff over there..
I am inside the caller jsp, inside his handleReqeust(HttpServletReqeust request)
method I am trying to forward the request to another JSP, to call the other JSP file to his handleRequest(HttpServletReqeust request) off course with the request object
I tried it:
RequestDispatcher dispatcher = request.getRequestDispatcher("/theSecondJspFile.jsp");
if (dispatcher != null)
dispatcher.forward(request, response);
but to make it work I need for it the object response, but I don't have it,
I am sure I missed something basic, but what?
From my question you can see, I don't have solid backround in java, so please correct me, or refer me to good guide if you feel it necessary
Thanks.
-------------------Edit--------------------------------------
I don't need a redirect, I just want to call another JSP file to his handleRequest method
I think it relate to HTML
What I can make out of your question is that you need to redirect to a secondpage.html from firstpage.html with some data. You can use both GET or POST method to send the data.
For the GET method just redirect to secondpage,html?data=value. The data will be available in the HttpRequest parameter in the controller of the secondpage.html where it can be used as required.
For the POST method you would need to post the data (using a form on firstpage.html) to secondpage.html. In the controller of the secondpage.html the data should be available in a similar way as before.
To include another JSP in a jsp :
<jsp:include page="foo.jsp"/>
You can find some reference material here.
I can not be sure, but what I think you are trying to do is to include a jsp page on to your jsp page and use the the objects and other variables declared in the first jsp page in your second.
<%# include file="mypage.jsp" %> should help you do this.
If this is not what you are looking for, please make your question tad bit more clear. some code will help really.
JSPs are supposed to be used to present the final result. JSPs are not supposed to be part of business tasks leading to this result. There you use normal Java classes for, starting with a servlet class. Let the HTTP request (the one which you enter in browser address bar or specify in some HTML link or form) point to the URL of the servlet instead. This way you can write Java code in the servlet the usual way to invoke other Java classes/methods and finally forward the request to a certain JSP file based on the outcome of the result and then just let that JSP present the final result.
To start with servlets, I'd suggest to read our Servlets info page.
I just added empty Iframe, and set his URL when I needed to call him
why use<bean:include instead of <jsp:include in struts?
from the documentation for bean:include
Perform an internal dispatch to the specified application component (or external URL) and make the response data from that request available as a bean of type String. This tag has a function similar to that of the standard jsp:include tag, except that the response data is stored in a page scope attribute instead of being written to the output stream. If the current request is part of a session, the generated request for the include will also include the session identifier (and thus be part of the same session).
first hit on google
bean:include works almost like jsp:include except that the result is stored in the page scope. This means that your code on the current page can access the results and manipulate it. See this page.