richfaces Process Bar (progress bar)

[Suresh Khant]

Hi All,

I am trying to implement progress ( process ) bar example which i need it to my interface , I have just copied the example in the richfaces site.
what i want is that once the user clicks on the button it should call a method which will take some time to finish the processing , while the processing is going , I just want to display a message indicating that there is some process going on .

in the code below once i click on the button it will call the method "processSomething" from mehtod"startProcess" and after finishing processing in this method , it show the processing bar which is not what i want.

it should show the processing bar while the processing is going on in the method "processSomething".

any one can help me to fix this issue

here is the code:

<ui:define name="body">
		<h:form>
			<a4j:outputPanel id="progressPanel">
            <rich:progressBar value="#{progressBarBean.currentValue}"
                interval="2000" label="#{progressBarBean.currentValue} %"
                enabled="#{progressBarBean.enabled}" minValue="-1" maxValue="100"
                reRenderAfterComplete="progressPanel" mode="ajax">
                <f:facet name="initial">
                    <br />
                    <h:outputText value="Process doesn't started yet" />
                    <a4j:commandButton action="#{progressBarBean.startProcess}"
                        value="Start Process" reRender="progressPanel"
                        rendered="#{progressBarBean.buttonRendered}"
                        style="margin: 9px 0px 5px;" />
                </f:facet>
                <f:facet name="complete">
                    <br />
                    <h:outputText value="Process Done" />
                    <a4j:commandButton action="#{progressBarBean.startProcess}"
                        value="Restart Process" reRender="progressPanel"
                        rendered="#{progressBarBean.buttonRendered}"
                        style="margin: 9px 0px 5px;" />
                </f:facet>
            </rich:progressBar>
        </a4j:outputPanel>

/**
 * 
 */
package com.lit.message.backoffice.web.bean;

import java.util.Date;

/**
 * @author techbrainless
 *
 */
public class ProgressBarBean {
	
	private boolean buttonRendered = true;
    private boolean enabled=false;
    private Long startTime;
    
 
 
    
    public String startProcess() {
        setEnabled(true);
        setButtonRendered(false);
        setStartTime(new Date().getTime());
        processSomething();
        return null;
    }

    public Long getCurrentValue(){
        if (isEnabled()){
        	Long current = (new Date().getTime() - startTime)/1000;
            if (current>100){
                setButtonRendered(true);
            }else if (current.equals(0)){
                return new Long(1);
            }
            return (new Date().getTime() - startTime)/1000;
        } if (startTime == null) {
            return Long.valueOf(-1);
        }
        else
            return Long.valueOf(101);
    }
    
    public boolean isEnabled() {
        return enabled;
    }

    public void setEnabled(boolean enabled) {
        this.enabled = enabled;
    }

    public Long getStartTime() {
        return startTime;
    }

    public void setStartTime(Long startTime) {
        this.startTime = startTime;
    }

    public boolean isButtonRendered() {
        return buttonRendered;
    }

    public void setButtonRendered(boolean buttonRendered) {
        this.buttonRendered = buttonRendered;
    }


    
    public void processSomething(){
    	//process something .., which requires some time 
    }
}

[Tim Holloway]

That's not going to work. An HTTP request doesn't return anything at all until all the code in the request handler has completely finished processing. So you'd get a long delay and then 100%.

To get a progress display, you're going to need to run the long-running display in a separate thread, start the thread in you backing bean, then return to the caller, leaving the thread to run.

You also need to make sure that the thread you start isn't tied to a transient object like a servlet request or you'll run out of HTTP request processors. Traditionally, I've simply set up what I call a "null servlet" whose init() method launched a thread engine which could be petitioned to run the threads on its own resource structure.