Job Scheduler in WAS

Introduction

This posting is how to for developing and scheduling jobs in WebSphere Application Server. IBM Rational Software Architect/Rational Application Developer is used for this example.

Requirement

IBM Rational Software Architect/Rational Application Developer.
A relational database (SQL Server/Oracle/My SQL etc.).
Knowledge in Java, J2ee and basic Websphere administration (to create data source and etc.)

Steps

Creating a WAS Scheduler
Creating a EJB Project with stateless session bean which will be used as job.
Creating a Dynamic Web Project to control the job.

1. Creating a WAS Scheduler.

Open Admin console.
To create a scheduler first have to create a data source.
Verify the connection is working.
No have to create a scheduler.
Go to Resources Schedulers.
Create a new scheduler.
Give a name, specify a JNDI name this will be used to control the jobs register to the scheduler, select data source JNDI name and JAAS alias for the data source.
Click Apply and save the configuration.
Now select the scheduler and click Create Tables.

2. Creating a EJB project.

Create a EJB project in IBM RSA/RAD.
Now create a stateless session bean in the EJB project with remote home interface as com.ibm.websphere.scheduler.TaskHandlerHome and remote interface as com.ibm.websphere.scheduler.TaskHandler
Now you have to change the JNDI of the Bean if you want it can remain as default.
The IDE will create a stub EJB Bean.

package ejbs;

public class TestBeanBean implements javax.ejb.SessionBean {

    static final long serialVersionUID = 3206093459760846163L;
    private javax.ejb.SessionContext mySessionCtx;
    public javax.ejb.SessionContext getSessionContext() {
        return mySessionCtx;
    }
    public void setSessionContext(javax.ejb.SessionContext ctx) {
        mySessionCtx = ctx;
    }
    public void ejbCreate() throws javax.ejb.CreateException {
    }
    public void ejbActivate() {
    }
    public void ejbPassivate() {
    }
    public void ejbRemove() {
    }
}

Now add the interface com.ibm.websphere.scheduler.TaskHandler and overrides the methods of the Interface and you have the stub of the job bean.

package ejbs;

import java.rmi.RemoteException;

import javax.ejb.EJBHome;
import javax.ejb.EJBObject;
import javax.ejb.Handle;
import javax.ejb.RemoveException;

import com.ibm.websphere.scheduler.TaskStatus;

public class TestBeanBean
    implements javax.ejb.SessionBean,com.ibm.websphere.scheduler.TaskHandler {

    static final long serialVersionUID = 3206093459760846163L;
    private javax.ejb.SessionContext mySessionCtx;
    public javax.ejb.SessionContext getSessionContext() {
        return mySessionCtx;
    }
    public void setSessionContext(javax.ejb.SessionContext ctx) {
        mySessionCtx = ctx;
    }
    public void ejbCreate() throws javax.ejb.CreateException {
    }
    public void ejbActivate() {
    }
    public void ejbPassivate() {
    }
    public void ejbRemove() {
    }
    public void process(TaskStatus taskStatus) throws RemoteException {
        // TODO Here implement the business logic of the job.
        System.out.println("Inside a job bean");
    }
    public EJBHome getEJBHome() throws RemoteException {
        return null;
    }
    public Handle getHandle() throws RemoteException {
        return null;
    }
    public Object getPrimaryKey() throws RemoteException {
        return null;
    }
    public boolean isIdentical(EJBObject object) throws RemoteException {
        return false;
    }
    public void remove() throws RemoteException, RemoveException {

    }
}

3. Creating a Dynamic web project.

Create a Dynamic web application.
Create the folder called jsp under Webcontent and put the following two JSP files.

testJob.jsp

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>
<HEAD>
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<META name="GENERATOR" content="IBM Software Development Platform">
<META http-equiv="Content-Style-Type" content="text/css">
<TITLE>Test Job</TITLE>
<SCRIPT>
    function setAction(action){
        document.getElementById('action').value=action;
    }
    function init(){
        var error = document.forms[0].error.value;
        if(error.lentgh > 0){
            alert(error);
        }
    }
    function getParams(){
        var action = document.forms[0].action.value;
        if(action == 'start'){
            var url = '<%=request.getContextPath()%>/jsp/testJobParams.jsp';
            var secStr = window.showModalDialog(url,”,'dialogHeight:422px;dialogWidth:550px;center:yes;scroll:no;status:no');
            if(secStr['starttime'] == undefined){
                return;
            }
            document.getElementById('starttime').value=secStr['starttime'];
            document.getElementById('interval').value=secStr['interval'];
        }
    }
</SCRIPT>
</HEAD>
<BODY>

    <table width="100%" height="100%">
        <tr>
            <td align="center" valign="middle">
                <form action="<%=request.getContextPath()%>/TestJob" onsubmit="getParams();">
                    <input type=hidden name="action" id="action"/>
                    <input type=hidden name="starttime" id="starttime"/>
                    <input type=hidden name="interval" id="interval"/>
                    <TABLE>
                        <tr>
                            <td>Test Job Status</td>
                        </tr>
                        <tr>
                            <td>Status: ${requestScope.STATUS}</td>
                        </tr>
                        <tr>
                            <td>Next Sheduld Time: ${requestScope.NEXT}</td>
                        </tr>
                        <tr>
                            <td class="fontSpecifications">${requestScope.error}</td>
                        </tr>
                    </TABLE>
                    <table>
                        <tr>
                            <td align="center">
                                <input type=submit onclick="setAction('start')" value="Start"></submit>
                                <input type=submit onclick="setAction('suspend')" value="Suspend"></submit>
                                <input type=submit onclick="setAction('resume')" value="Resume"></submit>
                                <input type=submit onclick="setAction('cancel')" value="Cancel"></submit>
                            </td>
                        </tr>
                    </table>
                </form>
            </td>
        </tr>
    </table>
</BODY>
</html>

testJobParams.jsp

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<HTML>

<HEAD>
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<META name="GENERATOR" content="IBM Software Development Platform">
<META http-equiv="Content-Style-Type" content="text/css">
<TITLE>Test Job Params</TITLE>
<SCRIPT>
    var r = new Array();
    function ok(){
        var date_val = document.getElementById('date').value;
        var time_val = document.getElementById('time').value;
        var int_val = document.getElementById('int_val').value;
        var int_type = document.getElementById('int_type').value;
        r['starttime'] = date_val+' '+time_val;
        r['interval'] = int_val+”+int_type
        window.close();
    }
    function cancel(){
        r['starttime'] = undefined;
    }
    function windiowUnload(){
        window.returnValue = r;
    }
</SCRIPT>
</HEAD>
<BODY onunload="windiowUnload()">
    <form>
    <table width="100%" height="100%">
        <tr>
            <td align="center" valign="middle">
                <table>
                    <tr>
                        <td colspan="2">
                            Enter Date And time to start the job
                        </td>
                    </tr>
                    <tr>
                        <td class="fontSpecifications">Date (dd/MM/yyyy):</td>
                        <td><input type="text" name='date'  size=10 maxlength="10" id='date'/></td>
                    </tr>
                    <tr>
                        <td class="fontSpecifications">Time (HH24:MI):</td>
                        <td><input type="text" name='time' size="5" maxlength="5" id='time'></td>
                    </tr>
                    <tr>
                        <td class="fontSpecifications">Interval:</td>
                        <td>
                            <input type="text" size="4" name='int_val' alt="Enter Numeric Value" id='int_val'>
                            <select name='int_type' id='int_type'>
                                <OPTION value="seconds">Second(s)</OPTION>
                                <OPTION value="minutes">Minute(s)</OPTION>
                                <OPTION value="hours">Hour(s)</OPTION>
                                <OPTION value="days">Day(s)</OPTION>
                                <OPTION value="months">Month(s)</OPTION>
                                <OPTION value="years">Years(s)</OPTION>
                            </select>
                        </td>
                    </tr>
                    <tr>
                        <td colspan="2" align="right">
                            <input type="button" value="Ok" onclick="ok();"/>
                            <input type="button" value="Cancel" onclick="cancel()"/>
                        </td>
                    </tr>
                </table>
            </td>
        </tr>
    </table>
    </form>
</BODY>
</HTML>

Create a servlet TestJob

package com.servlets;

import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Iterator;

import javax.naming.InitialContext;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.ibm.websphere.scheduler.BeanTaskInfo;
import com.ibm.websphere.scheduler.Scheduler;
import com.ibm.websphere.scheduler.TaskHandlerHome;
import com.ibm.websphere.scheduler.TaskStatus;

public class TestJob extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet {
    private static final long serialVersionUID = 9166651663233476722L;

    public TestJob() {
        super();
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String action = request.getParameter("action");
        System.out.println("Action >>---> " + action);
        String status = null;
        String error = "";
        Scheduler scheduler;
        int intStatus = -99;
        boolean isReg = false;
        SimpleDateFormat dateFormat = new SimpleDateFormat("dd/MM/yyyy HH:mm");
        try {
            scheduler = (Scheduler) new InitialContext()
                    .lookup("sche/test");// JNDI Name of the scheduler
            Iterator iter = scheduler.findTasksByName("Test Job");
            System.out.println("Size of iter " + iter.hasNext());
            BeanTaskInfo taskInfo = null;
            if (iter.hasNext()) {
                taskInfo = (BeanTaskInfo) iter.next();
                System.out.println(" Next fire time "
                        + taskInfo.getNextFireTime());
                isReg = true;
                intStatus = taskInfo.getStatus();
            }
            if (action != null && action.equals("start")) {
                String startTime = request.getParameter("starttime");
                String interval = request.getParameter("interval");
                System.out.println("St Int >>---> "+startTime+" "+interval);
                Date startDt = dateFormat.parse(startTime);
                if (!isReg) {
                    taskInfo = (BeanTaskInfo) scheduler
                            .createTaskInfo(BeanTaskInfo.class);
                    Object o = new InitialContext()
                            .lookup("ejb/scheduler/TestBeanHome");
                    TaskHandlerHome home = (TaskHandlerHome) javax.rmi.PortableRemoteObject
                            .narrow(o, TaskHandlerHome.class);
                    taskInfo.setTaskHandler(home);
                    taskInfo.setStartTime(startDt);
                    taskInfo.setNumberOfRepeats(-1);//If the value is positive the job will run specified times.
                    taskInfo.setName("Test Job");
                    taskInfo.setRepeatInterval(interval);
                    TaskStatus ts = scheduler.create(taskInfo);
                    System.out.println("Task created with id: "
                            + ts.getTaskId() + " " + ts.getStatus() + " "
                            + ts.getNextFireTime());
                    //return mapping.getInputForward();
                } else {
                    scheduler.cancel(taskInfo.getTaskId(), true);
                    taskInfo = (BeanTaskInfo) scheduler
                            .createTaskInfo(BeanTaskInfo.class);
                    Object o = new InitialContext()
                            .lookup("ejb/scheduler/TestBeanHome");
                    TaskHandlerHome home = (TaskHandlerHome) javax.rmi.PortableRemoteObject
                            .narrow(o, TaskHandlerHome.class);
                    taskInfo.setTaskHandler(home);
                    taskInfo.setStartTime(startDt);
                    taskInfo.setNumberOfRepeats(-1);
                    taskInfo.setName("Test Job");
                    taskInfo.setRepeatInterval(interval);
                    TaskStatus ts = scheduler.create(taskInfo);
                    System.out.println("Task created with id: "
                            + ts.getTaskId() + " " + ts.getStatus() + " "
                            + ts.getNextFireTime());
                }
                intStatus = taskInfo.getStatus();
            }else if (action != null && action.equals("suspend")) {
                System.out.println("Inside Task Suspend Before if");
                if (taskInfo != null) {
                    System.out.println("Inside Task Suspend");
                    TaskStatus taskStatus = scheduler.suspend(taskInfo.getTaskId());
                    System.out.println("Status "+taskStatus.getStatus());
                    intStatus = taskStatus.getStatus();
                }
            }else if (action != null && action.equals("resume")) {
                System.out.println("Inside Task Suspend Before if");
                if (taskInfo != null) {
                    System.out.println("Inside Task Suspend");
                    TaskStatus taskStatus = scheduler.resume(taskInfo.getTaskId());
                    System.out.println("Status "+taskStatus.getStatus());
                    intStatus = taskStatus.getStatus();
                }
            }else if (action != null && action.equals("cancel")) {
                System.out.println("Inside Task Suspend Before if");
                if (taskInfo != null) {
                    System.out.println("Inside Task Suspend");
                    TaskStatus taskStatus = scheduler.cancel(taskInfo.getTaskId(),true);
                    System.out.println("Status "+taskStatus.getStatus());
                    intStatus = taskStatus.getStatus();
                }
            }
            if (intStatus == -99) {
                status = "NOT SCHEDULED";
            } else {
                switch (intStatus) {
                case TaskStatus.SCHEDULED:
                    status = "SCHEDULED";
                    break;
                case TaskStatus.COMPLETE:
                    status = "COMPLETE";
                    break;
                case TaskStatus.INVALID:
                    status = "NOT SCHEDULED";
                    break;
                case TaskStatus.RUNNING:
                    status = "RUNNING";
                    break;
                case TaskStatus.SUSPENDED:
                    status = "SUSPENDED";
                    break;
                case TaskStatus.CANCELLED:
                    status = "CANCELLED";
                    break;
                }
            }
            request.setAttribute("STATUS", status);
            if(taskInfo != null)
                request.setAttribute("NEXT", taskInfo.getNextFireTime().toString());
            System.out.println("Task Status " + status);

        } catch (Exception e) {
            e.printStackTrace();
            error = "Error: "+ e.getMessage();
        }
        request.setAttribute("error", error);
        RequestDispatcher dispatcher = getServletContext().getRequestDispatcher("jsp/testJob.jsp");
        dispatcher.forward( request, response );

    }
}