There is an application that stores photos in oracle db (oracle multimedia format). There is a JAVA servlet page that handle the connection and the SQLs ..., and there are JSP pages to show the images in browser.
There is a delete function in the JAVA page, when i click one thumbnail it navigates to the an other JSP and show the full size image. Here i would like to call the
public void deleteRowById( String selectId ) function which is in the JAVA servlet page. i would like to use a button, and i'm not realy know what is the proper way to call this function.
Any suggestions are welcome.
In the mean time i solved the situation. There is a java class that contains SQL statements -taht's what i would like to call with a form button.
1st JSP page show the button like delete, it navigates to an other JSP page via passing a parameter with post method, in this 2nd JSP page i call the main java class method that execute a delete statement then from the 2nd JSP page i navigate back with <jsp:forward page="1st_page.jsp"/>
Maybe not a cutting edge solution but works like charm :)
Related
Is there a way to let my page using ajax update a certain part content on my jsp webpage when the database change?
Currently I have:
1. db.java - a class to connect to database and query out the data I want
2. admin.jsp - a jsp page to display those data I want
My question:
How to using JSP and servlet automatically and dynamically update a page content while database changes, I know how to use JQuery ajax call servlet, but to achieved this, the only way I can get is set a time interval and loop repeating call ajax function, is this way workable ? or there are others better methods to do it?
I have been doing similer thing using jquery .load().. I have a struts2 action which is returning a VO ,which is binded with JSP view . i am calling same action via jquery .load() and updating JSP div.
I am using a polling timer which is handled in javascript to trigger this .
http://api.jquery.com/load/
Regds,
Amit
I have a button through which i INVOKE a java method :
<h:commandButton value="My Schedule" action="#{empDutySchedBean.viewMyTask}" rendered="#{welcomeBean.workSchedule}" class="mainLinks"/>
now through this method viewMyTask() i get a List of values returned from the database.
public List viewMyTask()
{
setEmpID((String) session.getAttribute("userName"));
setEmpDuty(ts.getMyTask(getEmpID()));
return empDuty;
}
From here i want tht with the click of a button, the user is redirected to another page and the List data shows up.
I dont understand how to REDIRECT to another HTML page and display the LIST data.
NOTE: --> this button is basically a menu on my webpage. For the other menus i have used an anchor tag. However as you cannot invoke a method using anchor tag, i have used button tag. But because of this, I am not being able to redirect
Some Ways that i think it can be solved are:
use anchor tag instead on button to redirect to the other page AND then use onLoad method of javascript to INVOKE java method
invoke another method after viewMyTask() to perform the redirection.
I dont kw how these methods would work though.
First off, I assume you already know how to return the data Java side, in which case this is really just a javascript question. To do simple post-gets, I usually use Ajax, like so:
new Ajax.Request(myUrlToCall, {
method:'POST',
onComplete: function(transport) {
window.location.replace(theRedirectUrl);
}
});
This will call whatever url you wanted to call Java side, then on the completion of this call, will redirect you to whatever url you want to go to. If you need to send some parameters to the java side, all you need to add is:
parameters:myParamVar,
after the method:'POST' line, and if you want your java side to return the url, then all you'd need to do is send it as json or similar in the response, then do:
window.location.replace(transport.responseJSON["theRedirectUrl"])
Hope that helped!
The problem I'm having is the following:
I have an app with two separate modes: A WebView for browsing and a custom Canvas. The custom Canvas captures handwriting samples for language placement exams. Here's how it works. A user logs in to Moodle via the WebView. After they log in, they navigate to a Quiz inside Moodle. They click a link on one of the Quiz's questions and this launches an Intent which hides the WebView and shows the Canvas. The user then writes (using a stylus) on the Canvas. When a user is finished writing their essay (or whatever), they press a button that uploads an image file to Moodle. I am able to upload images to a point, it's getting them to show up in the HTML page that the user clicked the link in originally (see above) and to get Moodle to commit them to permanent storage that is the problem. Normally this is all accomplished through AJAX (really AJAJ since it's JavaScript and JSON) and when the user drops a file on this one component, the component refreshes and uploads the file.
Here is the problem: I need the WebView so that students can log in to Moodle through Shibboleth. But because the underlying JavaScript in the browser makes AJAX calls to the Moodle server and since the Java side of Android doesn't have access to the DOM, I have use the Apache HTTP components library to make some of the connections below basically to preserve the state of the HTML page in WebView.
In a desktop browser on, say, Windows, I use WebScarab to monitor the browser's requests and this is what I see: the browser uploads a file to Moodle via five successive calls to the following scripts:
POST https://[moodle website]/repository/repository_ajax.php [posts multipart form data]
POST https://[moodle website]/repository/draftfiles_ajax.php [posts some params]
GET https://[moodle website]/draftfile.php/[some_id]/user/draft/[some_id]/[somefilename.png] [returns an icon of the image for a filepicker from YUI]
POST https://[moodle website]/mod/quiz/processattempt.php [returns HTML page]
GET https://[moodle website]/mod/quiz/summary.php [returns HTML page]
Some of these scripts return, as you'd expect, JSON data since they're AJAX and not HTML. The final two calls (4 & 5) return HTML. Now, I can make all of those calls in succession in either the WebView or the Apache HTTP library, but if I do so with WebView, only JSON data is returned to the WebView in calls 1-3 (WebView treats the JSON data as a page and displays it wiping out whatever HTML page was displayed in it). If I capture and process the JSON data using the Apache HTTP library in Java, then the JavaScript components internal to the page do not get updated. If I split the calls so that I send only calls 4 & 5 to the WebView, the HTML merely returns WebView to the first question of the exam and Moodle acts as if I haven't uploaded anything.
I can verify that files are uploading if I manually refresh (press a link) the JavaScript UI elements in the page. I can't expect students to do this, though, because the link to do so is very tiny and it's not obvious that it does a refresh. I need a way to programmatically refresh this one element (it's part of YUI) or to get Android and the Java side to play more nicely with the JavaScript/DOM side.
My question is: does anyone know a way to 1) fire off a drag and drop event using YUI to an element inside an HTML page or 2) a way to consume the JSON data and pass it to an element inside the HTML page.
I'm banging my head against a wall trying to figure this out.
OK, so I figured out that: javascript:document.getElementsByClassName(\"[name of link here]\")[0].click() works in Chrome on the desktop but doesn't work if I pass it to WebView.loadURL(). I just need to be able to simulate that click event reliably in WebView. It appears not to support click(). Anyone have any ideas?
The winning code is:
el = document.getElementsByClassName("[some element]")[0];
var event = document.createEvent("MouseEvents");
event.initEvent("click", true, true);
el.dispatchEvent(event);
This selects the link at [some element] and thereby fires an AJAX request that refreshes the FilePicker. For those working with Moodle, I had to add the above code to the same quiz question that handles so it is invoked by putting that code in its own function and calling it with WebView.loadURL("javascript:myRefreshFunction()").
I m trying to access JavaScript function from Servlet code. But I'm getting the error shown below.
Here is the code:
out.println("<FRAME src=\"javascript:parent.newWindow('" + URL+ "') \" scrolling=No noresize />");
And this is the error that occurs in JavaScript:
Object does not support this property or method;
You can't access a Javascript function from your servlet code. Javascript executes on the client (= your user's browser) and the servlet code executes on your server (for example Tomcat, JBoss, whatever you're using).
What are you trying to accomplish with your code? I'm sure there's a simpler way to do it than what you just described.
[edited]
I see you just updated your description, so here's my view:
I'm guessing that you want to display a page to the user and when the page is displayed, you want to open a new window which will display another page using the URL parameter to point its address. If this is the case, you should probably just do this in the first page's onLoad() Javascript event using window.open().
There is no newWindow property on a window object (which is what parent references), so this is not unexpected.
Maybe you are looking for the open method instead?
If so, then:
Putting it as the src of an iframe is a very strange thing to do
It will probably be zapped by pop-up blockers
Ok. You try to generate javascript code inside Servlet code. When you do, your code goes to Web browser and it's seen there as a html document with javascript inside. So, your error rather comes from web browser and links to javascript error. Probably it's newWindow method. To open new window you should call window.open() function, I guess.
Here is my situation: the user selects a section (for example from a dropdown) such as "Section1," "Section2" or "Section3." Then he clicks the OK button (or some link).
What I need to happen: after he clicks on that button/link, he will be redirected to the selected section, e.g. www.homepage.com/docs#section2.
So far, I have not been able to process the form from Link's onClick method, nor have I been able to call some clickLink on Link from the Button method onSubmit().
I would prefer not to use AJAX or JavaScript. How can I do this?
That's because a Link doesn't submit the form. It just acts as a link to somewhere. To access your formdata you'll need to submit the form first. Try using a SubmitLink instead of a Link and call
getRequestCycle().setRequestTarget
(new RedirectRequestTarget("www.homepage.com/docs#section2"));
from the onSubmit function of the SubmitLink.
Judging from the Javadoc this should work but I can't test it right now.
A RequestTarget that will send a redirect url to the browser. Use this if you
want to direct the browser to some external URL, like Google etc, immediately.
Or if you want to redirect to a Wicket page. If you want to redirect with a
delay the RedirectPage will do a meta tag redirect with a delay.
Did you try Link.setAnchor(Component)?