Very simple question: Call JavaBean method on page load?

Someone clicks on a URL that contains parameters like: http://server/page.jsf?param=b
How do I trigger a JavaBean method to run during page load? I see many JSF examples where JavaBean methods get called during form clicks and that works great but here I want to run code on page load.
This must be really simple; sorry I'm new to this technology.
Must I use <% ... %> syntax or can I use actual JSF tags or configuration to accomplish this?
Thanks very much in advance!

Putting a lot of logic in getter( ) function is not the best idea considering that getter( ) could be called all over the place. Using constructor for same purpose is also a bad idea especially with request scope beans. This could also happen many times at different stages. You are right, having a page load concept could be useful. Unfortunately JSF framework does not support. You could architect around it in case desperate. Or if using JSF implementation of certain vendors like IBM, you can take advantage of their implementation that was extended to support pageLoad and postBack events (similar to .NET).
Many postings on this forum dealt with topic. Feel free to review like this one:
http://forum.java.sun.com/thread.jspa?forumID=427&threadID=541382

Similar Messages

How to call java method on page load?

How to call java method on page load?
Thanks

Hey Dan,
Well, if you want to execute a java method when page is load, you need to put the clientlistener in af:document. Let me to show you an example (I can't find my post :P),
JSPX page:
<f:view>
<af:document>
<f:verbatim>
<script>
    function loadPage(event) {
        alert('Hello World!');
</script>
</f:verbatim>
<af:clientListener method="loadPage" type="load"/>
</af:document>
</f:view>If you try this code you can see that when the page has been load, you recieve the alert "Hello World!".
Furthermore, this is the javascript AJAX function that let you to call a servlet:
function ajaxFunction () {
    var httpRequest;
    if (window.XMLHttpRequest) {
        httpRequest = new XMLHttpRequest();
    } else if (window.ActiveXObject) {
        httpRequest = new ActiveXObject("Microsoft.XMLHTTP");
        httpRequest.overrideMimeType('text/xml');
    httpRequest.onreadystatechange = function() { alertContents(httpRequest); };
    httpRequest.open('GET', '/appname/servletname', false);
    httpRequest.send('');
function alertContents(httpRequest) {
    if (httpRequest.readyState == 4) {
        if (!httpRequest.status == 200) {
            alert('Request error. Http code: ' + httpRequest.status);
}Where 'appname' is your application name and 'servletname' is the name of the servlet that you want to call. Obviously, you can call any URL ;)
JVN

Preventing the method calling (WSDL Method) when page loads first

Hi Gurus,
I have created a WebService, which will return a set of data depending on some search criteria. If No search criteria is mentioned, then it will fetch all data.
I have successfully called that webservice using DataControl in ADF , now the issue is at time of the loading of ADF Page , it fetches all data.
But I want to fetch the data after pressing the search button in the Page, not at time of loading of the page.
Please help!!
Thanks in advance
SG_SOA

ADF : adfFacesContext.initialRender issue

A very simple question..Very Urgent

HI,
I have a very simple question.I am able to set up the client authentication as well as server authentication. Now do i need to authenticate (both server as well as client auth.) for every request i send to the server on https...i think it should be like that it should authenticate only for the first time and for the next upcoming requests in same session should not require any server or client authentication.. i think as it happens in browsers..
what is the fact actually??..can somebody put some light...right now in my case it is authenticating for every requests..
This is what i have done..
/****constructor part********/
// and tm are arrays of keymanagers and trustmanagers for client keystore and truststore
sslContext.init(km, tm, null);
HttpsURLConnection.setDefaultSSLSocketFactory(ssf);
HttpsURLConnection.setDefaultHostnameVerifier(new MYHostNameVerifier());
/****Method to send the request and response*********/
urlConn = (HttpsURLConnection)url.openConnection();
urlConn.setDoInput(true);
urlConn.setDoOutput(true);
OutputStream os = urlConn.getOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(os);
oos.writeObject(someobject);
oos.flush();
InputStream is1 = urlConn.getInputStream();
ObjectInputStream ois = new ObjectInputStream(is1);
SomeObject retObj = null;
retObj = (SomeObject)ois.readObject();
ois.close();
System.out.println("Get String>>>>> "+retObj.getString());
I am creating the object of this class..and calling the method again and again for sending requests and response..so i think handshake everytime i call the method...what i want is that handshake should happen for the first time and for the next requests no handshake or certificates should be checked or processed..
is it possible ..how..what i need to do for that..
please help me in this..
Akhil Nagpal

Hi,
how could I achieve SSL Session Resumption using HttpsURLConnection.
Thanks.

This is a very simple question,but I don't know.Please me.Thank you!

I am a Chinese student in a university.I have a very simple question to ask.
I have writed a EJB module,and I have deployed to Weblogic8.1 successfully.
1.Now I want to write a client program.Is it necessary that the client program is packaged in the EJB package.For example ,the EJB package is Beans,is "package Beans " or "import Beans.*" necessary in my client program.
2.If I only know the EJB interfaces,that means the EJB module is writed by other programer.I want to know how I can write the client program.How can I call EJB module's method writed by other programer.Could you give me a simple example?
Thank you very much.

I have writed a EJB module,and I have deployed to
Weblogic8.1 successfully.:-)
1.Now I want to write a client program.Is it
necessary that the client program is packaged in the
EJB package.For example ,the EJB package is Beans,is
"package Beans " or "import Beans.*" necessary in my
client program.You need not package your client with the EJB. It can be a JSP/servlet or a stand-alone application.
2.If I only know the EJB interfaces,that means the
EJB module is writed by other programer.I want to
know how I can write the client program.How can I
call EJB module's method writed by other
programer.Could you give me a simple example?
import java.util.*;
import javax.naming.*;
import javax.rmi.PortableRemoteObject;
import examples.*;
class TestEJBHello {
    public static void main(String[] args) {
        Context context   = null;
        Object object     = null;
        // Hashtable for environment properties.
        Hashtable env = new Hashtable();
        env.put(Context.INITIAL_CONTEXT_FACTORY, "weblogic.jndi.WLInitialContextFactory");
        env.put(Context.PROVIDER_URL, "t3://localhost:7001");
        HelloHome home            = null;
        HelloWorld hello          = null;
        try {
            context     = new InitialContext(env);
            object      = context.lookup("HelloWorldTest");
            System.out.println(" JNDI Looked up >>> " +object);
            home        = (HelloHome)PortableRemoteObject.narrow(object, HelloHome.class);
            hello       = home.create();
            System.out.println(hello.hello());
        } catch(Exception e) {
            e.printStackTrace();
        } finally {
            close(context);        // Closes the initial context.
    private static void close(Context context) {
        try {
            context.close();
            System.out.println("*** Context closed. ***");
        } catch (NamingException namingException) {
            namingException.printStackTrace();
        } catch(Exception exception) {
            exception.printStackTrace();
}Here's a sample client app code I use for a HelloWorld EJB. You need to have a EJB client JAR containing the home and remote interfaces in the classpath during compile time and runtime.
x

Very simple question, how do you configure windows 8.1 to use a SF card as the default install location for software applications?

Very simple question, how do you configure windows 8.1 to use a SD card / external drive as the default install location for software applications? Primarily interested in apps installed from the windows store. This should be available in the settings
charm within the windows store. This must have been overlooked in the development of windows 8.1 or is a bug.
Regards, Bill
* update
I've tried modifying this key and the path:
“HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Appx”
http://answers.microsoft.com/en-us/windows/forum/windows_8-windows_store/how-do-you-install-apps-in-windows-8-from-the/c4fbe2a8-fd3d-41c1-b9a6-6f881eed374f
Also tried using symlinks as detailed here:
http://social.technet.microsoft.com/Forums/windows/en-US/8eee52c2-db0f-4032-8c72-7cd999e8b41a/windows-8-apps-installing-to-secondary-drive?forum=w8itprogeneral

Here's some links I've used to try to figure this out:
http://social.technet.microsoft.com/Forums/windows/en-US/2dfc0cd9-7d1b-41de-abce-e03fb6a5a383/metro-apps-not-working-in-windows-8-pro-x64-after-moving-users-and-programdata-folders?forum=w8itproinstall
http://social.technet.microsoft.com/Forums/windows/en-US/8eee52c2-db0f-4032-8c72-7cd999e8b41a/windows-8-apps-installing-to-secondary-drive?forum=w8itprogeneral
http://social.technet.microsoft.com/Forums/windows/de-DE/f5e33ac9-beab-4b99-b3ca-7cb5e6f415e4/how-do-you-change-metro-apps-default-install-location?forum=w8itprogeneral
Regards, Bill
The registry method does not work with 8.1. I found this out the hard way. Doing it on 8.1 will leave you reinstalling the OS if you didn't do a SRP beforehand.

HT4753 I have a very simple question: how do I view where Lion has autosaved my current version to (without the convoluted route of using finder)? In days gone by i'd simply use the save as function to see where it was being saved.

I have a very simple question: how do I view where Lion has autosaved my current version to (without the convoluted route of using finder)? In days gone by i'd simply use the save as function to see where it was being saved.

It's actually even easier than using Save As to see the full path to the currently open document. Just do a "Secondary click" on the document title in its window's title bar.
Like you, I relied upon Save As my whole life to check a file's location and considered it a must-have capability. Turns out it's even faster to use the single-click method to reveal the full path to the open document. It displays the entire path to the current document starting from the level of your Mac, and works for files stored on drives as well as iCloud.
If you're not sure how to do a secondary click, go into System Preferences, select Trackpad, Point & Click to find the current preference for secondary click on your Mac. If you happen to have a mouse with more than one button, it's probably the right button. As a trackpad user, I check the box to "Click or tap with two fingers," so a simple two finger tap on the title of an open document reveals its full path. This feature actually has been around for a very long time.
Note that this is not the same thing as the Autosave and Versions menu, which is exposed using a little drop down triangle to the right of the title. There is no visual clue for the presence of this feature - you just have to know it's there, probably because this feature goes all the way back to pre-OS X days.

VERY SIMPLE QUESTION REGARDING UML DIAGRAMS IN JDEVELOPER

Hello there,
I have a very simple question. I want to know how I can convert a class diagram that I have created in jdeveloper into a jpg image so I can put in word. When I try exporting it only has the uml to xmi option
Does anyone have a suggestion?

Hi,
Right mouse click on the class diagram,
than click publish diagram on the context menu
and save as jpg where ever you want...
Boris

A very very very simple question

Hi guys,
I have a very simple question and standard but I cant find anywhere...
I have two dateTime variables, i need to calculate difference between this dates in days, thats it.
I tried all functions and tried without success a Java Embed task but I couldnt retrieve this objects as java.util.Date so I couldnt calculate exactly the difference in days like this pure java code:
(dataVencimento.getTime() - dataReferencia.getTime()) / 86400000L)
can you help me this?

Hi Jose
Just see if these alternate approaches works. I know there may be lot like this and you may be lucky to find out simple out of box solution itself. If you want to solve this issue and move ahead, gives these approaches a shot.
1. Create a very simple standalone WebService that takes 2 input date elements (can be of Date type or String type. If string type, convert to date in your java code). Create a simple operation like getDaysBetween(firstDate, secondDate). In the generated webservice impl class, use the java code apis (refer earlier link for usage), and get the difference. Return this value. NOW, invoke this WebService in your BPEL Process, and pass your 2 inputs (if the bpel payload elemetns are date object or string objects of date), and get output, and then use this output in your continuing bpel process.
2. This approach, I did a long back. When we insert any expression using XPath, in that editor window on bottom right side, we see many categories and for each category we see list of functions we can use, like for String, we can use concat etc. I vaguely remember reading somewhere, that we can add our own custom functions also in this section. So explore this direction and see if you can add your own function and then use that fucntion with your 2 input dates.
I have not given solution to your problem, but may be these directions can help you move ahead. Or something along these lines.
Thanks
Ravi Jegga

Can anyone answer a very simple question for me ive heard the apple was giving a free iphone 4 or 4s bumper away is there any truth to that?

can anyone answer a very simple question for me ive heard the apple was giving away iphone 4 or 4s bumpers is there any truth to that?

Not any more, no. There was a free bumper program back when the iPhone 4 originally came out. It has long since expired.

Crash when calling Clipboard.GetContent() in Page Loaded event

Hello
I found a crash when using
Clipboard.GetContent() method ,
the steps to reproduce this are very simple:
-create C# Windows store application ,
-add loaded event for main page
-call Clipboard.GetContent() inside it(loaded event handler).
-run the application as release Ctrl+F5 , the application will crash , note that when you run as debug no problems
-this problem appears not on GetContent() only , it appears when you use any method of ClipBoard class indside main page loaded event.
Is this bug? , if yes , what is the workaround for this.

Hi shaker,
Firstly, I have to say that, yes, I can reproduce your issue on my side.
However, as far as I know that the Clipboard operations are used to enable users to cut, copy, and paste data, but why you just call the Clipboard.GetContent() method in the Grid_Loaded event? Could you please show me more information
about your requirement so that I can better understand your scenario?
Thanks.
Vicky Song [MSFT]
MSDN Community Support | Feedback to us
Develop and promote your apps in Windows Store
Please remember to mark the replies as answers if they help and unmark them if they provide no help.

How to execute a method after page Load?

My question is very similar to what was discussed in following thread:
How to execute a method after page Load?
My requirement is that I want to run a method in backing bean of a page, immediately after the page gets loaded. In that method I want to invoke one of the method action included in the pagedef of this page, conditionally.
I tried using the approach given in the above thread, i.e to use <f:view afterPhase="#{backing_security.setPermPriv}">, but the problem is that our page is not using 'f:view' , so I explicitly added one f:view with afterPhase property set , but it is not working, page it self is not getting loaded, it is throwing the error:
Root cause of ServletException.
java.lang.IllegalStateException: <f:view> was not present on this page; tag [email protected]e8encountered without an <f:view> being processed.
     at org.apache.myfaces.trinidad.webapp.UIXComponentELTag.setProperties(UIXComponentELTag.java:108)
     at javax.faces.webapp.UIComponentClassicTagBase.findComponent(UIComponentClassicTagBase.java:733)
     at javax.faces.webapp.UIComponentClassicTagBase.doStartTag(UIComponentClassicTagBase.java:1354)
     at org.apache.myfaces.trinidad.webapp.UIXComponentELTag.doStartTag(UIXComponentELTag.java:71)
     at oracle.adfinternal.view.faces.taglib.UIXQueryTag.doStartTag(UIXQueryTag.java:41)
     at oracle.adfinternal.view.faces.unified.taglib.UnifiedQueryTag.doStartTag(UnifiedQueryTag.java:51)
     at oracle.jsp.runtime.tree.OracleJspBodyTagNode.executeHandler(OracleJspBodyTagNode.java:50)
     at oracle.jsp.runtime.tree.OracleJspCustomTagNode.execute(OracleJspCustomTagNode.java:262)
     at oracle.jsp.runtime.tree.OracleJspNode.execute(OracleJspNode.java:89)
     at oracle.jsp.runtimev2.ShortCutServlet._jspService(ShortCutServlet.java:89)
     at oracle.jsp.runtime.OracleJspBase.service(OracleJspBase.java:29)
     at oracle.jsp.runtimev2.JspPageTable.compileAndServe(JspPageTable.java:665)
     at oracle.jsp.runtimev2.JspPageTable.service(JspPageTable.java:387)
     at oracle.jsp.runtimev2.JspServlet.internalService(JspServlet.java:822)
     at oracle.jsp.runtimev2.JspServlet.service(JspServlet.java:746)
Please help to resolve this issue, or am I doing anything wrong?

Hi,
I assume that your view is a page fragment and here - indeed - the f:view tag cannot be used. If you use ADF then one option would be to use a custom RegionController on the binding layer to listen for the render phase to invoke the method. Another option would be to use a hidden field (output text set to display="false" and have this component value referencing a managed bean property. The managed bean property's getter method can now be used to invoke the method you want to run upon view rendering
Frank

Simple Question Calling methods from Java files through JSP without JVM

Hi.
I've got a simple question (forigve my newbieness)...
If I'm running Tomcat can I exectue a method in a compiled Java file from a JSP page without having the JVM installed on the server?
Any thoughts or additional comments would be appreciated.
Many thanks.

No... but that's because you can't run Tomcat without
a JVM installed on the server.
If you are running Tomcat, you are running a JVM for
the JSP pages to run in, in which case, yes, the JSP
pages can call the other Java code... as long as it's
in the classpath.Thanks a lot for the replies.
So just to check, if I sign up with a hosting company that offers Tomcat then the JVM will be installed on the server and I can call other Java code as long as it's in the classpath?
I just want to make sure before I sign up with a hosting company =D
Thanks again!

Method called three times on page loading

I have a page with panelTabbed and several showDetailItems. On the first showDetailItem I have ADF Query component with the results table.
I want the second showDetailItem to be enabled or disabled depending on whether there is a selected row in the results table or not.
I have second showDetailItem's Disabled property set to an EL expression referring to a method in a backing bean.
This method is called three times during initial page loading. I suspected that it was caused by some partialTriggers, but without any partialTriggers
ADF behave the same way.
Moreover, first two times there is a selected row in an iterator. Only the third time there's no selected row (empty initial state of the results table).
And if this method returns false (not disabled) first two times and true (disabled) third time only, the second showDetailItem is enabled after page is loaded.
What is responsible for these redundant calls of the method?

Studio Edition Version 11.1.2.0.0
Build JDEVADF_11.1.2.0.0_GENERIC_110531.1615.6017

Very simple question from a beginner

I am currently doing a little exercise, but I ran into a problem. I have written a class that supports operations on rational number. The fields are two long variables, one each that stores the numerator and denominator.
I have made add, subtract, multiply, and divide methods...
1. what I need help in is: beingh able to store the rational number in reduced for, with the denominator always positive
2. constructing a toString method, equals method, and compareTo method.
3. it also says "make sure the toString method correctly handles the case in which the denominator is zero by throwing an exception.
I have been working on this for a long time now, an I am stuck at this point.
I know this will be very simple for you guys and gals, but I am a beginner. Please offer some input, advice, and/or some code to help me get past this problem.
Thanks so much,
Jason

ok, here is what I have so far
public class Rational {
     public long num, den;
     public Rational(long n,long d) {
          this.num = n;
          this.den = d;
     public static void main(String args[]) {
          Rational r = new Rational(1,2);
          Rational s = new Rational(3,4);
          Rational rmuls = r.multiply(s);
          Rational rdivs = r.divide(s);
          Rational radds = r.add(s);
          Rational rsubs = r.subtract(s);
          r.print();
          s.print();
          rmuls.print();
          rdivs.print();
          radds.print();
          rsubs.print();
     public void print(){
          System.out.println(this.num+ "/" +this.den);
     public Rational multiply(Rational t){
          long n;
          long d;
          n = this.num*t.num;
          d = this.den*t.den;
          Rational answer = new Rational(n,d);
          return answer;
     public Rational divide(Rational t){
          long n;
          long d;
          n = this.num*t.den;
          d = this.den*t.num;
          Rational answer = new Rational(n,d);
          return answer;
     public Rational add(Rational t){
          long n;
          long d;
          n = (t.den*this.num)+(t.num*this.den);
          d = t.den*this.den;
          Rational answer = new Rational(n,d);
          return answer;
     public Rational subtract(Rational t){
          long n;
          long d;
          n = (t.den*this.num)-(t.num*this.den);
          d = t.den*this.den;
          Rational answer = new Rational(n,d);
          return answer;
     //public int compareTo (Rational t)??????

Very simple question: Call JavaBean method on page load?

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