TehNrd

<apex:page controller="batchStatus">
    <apex:form>
        <apex:commandButton value="Start Batch Job" action="{!startBatch}" reRender="jobs,error"/> 
        <apex:outputText id="error" value="{!error}" style="font-weight: bold; color: red"/>
 
        <br/><br/>
        <c:batchJobs id="jobs" numberOfJobs="20"/>
    </apex:form>
</apex:page>

<apex:component controller="batchJobs" selfClosing="true">
    <apex:attribute name="numberOfJobs" type="Integer" assignTo="{!numberOfJobs}" description="The number of batch jobs to display in the table."/>
 
    <!-- Here is the css styles that will be used for the progress bars -->
    <style>
        .progressBar{
            background-color: #f8f8f8;
            border:1px solid #DDDDDD;
            height: 19px;
            width: 300px;
            -moz-border-radius: 5px; 
            -webkit-border-radius: 5px;
        }
        .progress{
            background-color: #F7B64B;
            border:1px solid #E78F08;
            height: 100%;
            margin: -1px;
            text-align: center;
            -moz-border-radius: 5px; 
            -webkit-border-radius: 5px;
            line-height: 18px;
        }
    </style>
 
    <!-- This action poller will check the status of the batch jobs every 5 seconds -->
    <apex:actionPoller rerender="jobs" interval="5"/>
 
    <apex:pageBlock title="Batch Apex Jobs">
        <apex:pageBlockTable value="{!batchJobs}" var="b" id="jobs">
            <apex:column headerValue="Apex Class" value="{!b.job.ApexClass.Name}"/>
            <apex:column value="{!b.job.CreatedDate}"/>
            <apex:column value="{!b.job.CreatedById}"/>
            <apex:column value="{!b.job.Status}"/>
            <apex:column width="320px" >
 
                <!-- Here with have two divs that construct our progresses bar. An outter which is the entire bar,
                and and inner that represents the percent complete. We simply pass the percentComplete value to
                the inner div width and this will show how far along the job is. Brilliant! -->
 
                <div class="progressBar">
                    <div class="progress" style="width: {!b.percentComplete}%;">
                        {!b.percentComplete}%
                    </div>
                </div>
 
            </apex:column>
            <apex:column value="{!b.job.CompletedDate}"/>
        </apex:pageBlockTable>
    </apex:pageBlock>
 
</apex:component>

public class batchJobs{
 
    public List<BatchJob> batchJobs;
    public Integer numberOfJobs {get; set;}
 
    public List<BatchJob> getBatchJobs(){
        //Create new list of BatchJobs, a wrapper class that includes the job and percent complete.
        batchJobs = new List();
 
        //If number of jobs was not defined, default to 20
        if(numberOfJobs== null || numberofJobs <= 0){
            numberofJobs = 20;
        }
 
        //Query the Batch apex jobs
        for(AsyncApexJob a : [select TotalJobItems, Status, NumberOfErrors, MethodName, JobType, JobItemsProcessed, Id, CreatedDate, CreatedById, CompletedDate, ApexClassId, ApexClass.Name From AsyncApexJob order by CreatedDate desc limit :numberOfJobs]){
            Double itemsProcessed = a.JobItemsProcessed;
            Double totalItems = a.TotalJobItems;
 
            BatchJob j = new BatchJob();
            j.job = a;
 
            //Determine the pecent complete based on the number of batches complete
            if(totalItems == 0){
                //A little check here as we don't want to divide by 0.
                j.percentComplete = 0;
            }else{
                j.percentComplete = ((itemsProcessed  / totalItems) * 100.0).intValue();
            }
 
            batchJobs.add(j);
        }
        return batchJobs;
    }
 
    //This is the wrapper class the includes the job itself and a value for the percent complete
    public Class BatchJob{
        public AsyncApexJob job {get; set;}
        public Integer percentComplete {get; set;}
    }
 
    /*--------------------TEST METHOD------------------------*/
    static testMethod void batchStatusBarTest(){
        batchJobs controller = new batchJobs();
        controller.getBatchJobs();
    }
}

public void startBatch(){
	error = '';
	batchJob job = new batchJob();
	List<AsyncApexJob> openJobs = [select Id from AsyncApexJob where Status = 'Processing' OR Status = 'Queued']; 
 
	if(openJobs.size() < 5){
	        ID batchprocessid = Database.executeBatch(job);
	}else{
		error = 'WHOA BUDDY! Only five batch jobs at a time.';
	}
}

global class batchJob implements Database.Batchable<SObject>{
 
    global database.querylocator start(Database.BatchableContext bc){
        return Database.getQueryLocator('select Id, Name from Account where Type = \'Batch Test\'');
    }
 
    global void execute(Database.BatchableContext bc, sObject[] objects){
        List<Account> accns = new List<Account>();
 
        for(sObject s : objects){
            Account a = (Account)s;
            a.Description = 'batch testing. blah blah blah.  ' + system.now();  
            accns.add(a);
        }
        update accns;
    }
 
    global void finish(Database.BatchableContext bc){
       system.debug('all done');
    }
}