Java API to manipulate BPEL 10g processes

Once BPEL processes are deployed onto servers then they are available in two forms to be invoked

• As a webservice through WSDL/SOAP interface
• Java component

In this article we see basics behind java client to inoke BPEL processes.

Oracle provide java api, also called as 'Java Business Delegates' API to manipulate deployed BPEL processes.This functionality is provided as part of below jars.

• orabpel.jar 
• orabpel-common.jar
• oracle_http_client
• orabpel-boot

Major steps involved in using this API are

1. Add appropriate Oracle BPEL jar files to your java client application classpath.
2. Get the handle to com.oracle.bpel.client.Locator object
3. Build com.oracle.bpel.client.util.WhereCondition object to form a query to be executed against SOA data source
4. Get tha handle to  com.oracle.bpel.client.dispatch.IDeliveryService object from the reference of Locator object
5. Build com.oracle.bpel.client.NormalizedMessage to create input message
6. Call appropriate method  (deliveryService.request(..)/deliveryService.post(...)) to perform BPEL invocation

 Note that only 1st nd 2nd  steps are mandatory and remaining steps are optional and required depending on tasks you perform on BPM engine.

If you take a task of deleting a bpel process from BPEL domain then following code provides necessary steps

try{

com.oracle.bpel.client.IInstanceHandle instance;

com.oracle.bpel.client.IInstanceHandle[] instances;

String instanceKey = null;

//processInstanceId is a BPEL variable holding process_instance_id to be deleted

instanceKey =(java.lang.String)getVariableData("processInstanceId ");

Locator locator = new Locator("default", "welcome1");

// Set the whereclause

WhereCondition cond1 = new WhereCondition( "cikey = ?" );

WhereCondition cond2 = new WhereCondition( "process_id = ?" );

//set query parameters

cond1.setLong(1,Long.parseLong(instanceKey));

cond2.setString(1,"BPELProcess2");

//I am converting cond1 to process_id= ? and cikey = ?

cond1.prepend("and").prepend(cond2);

// Perform the query using the Locator

instances =locator.listInstances(cond1);

instance = instances[0];

instance.delete(); // deletes instance trace  from data source

//instance.abort(); // terminates instance trace  from data source

//instance.cancel(); // canceles instance trace  from data source

addAuditTrailEntry("BPELProcess2 instance deleted: "+instanceKey);

}catch(Exception e){

addAuditTrailEntry(e.getMessage());

}

If you take a task of recovering BPEL call back messages then following code provides necessary steps

package bpelrecovery;

import com.oracle.bpel.client.*;

import com.oracle.bpel.client.util.SQLDefs;

import com.oracle.bpel.client.util.WhereCondition;

import java.util.ArrayList;

import java.util.Hashtable;

import java.util.List;

import javax.naming.Context;

public class bpelrecovery {

public bpelrecovery() {

}

public static void main(String[] args) {

bpelrecovery recover = new bpelrecovery();

String rtc = "";

try{

rtc = recover.doRecover();

}

catch (Exception e){

e.printStackTrace();

}

}

private void recoverCallbackMessages(List messages)

throws Exception

{

String messageGuids[] = new String[messages.size()];

for(int i = 0; i < messages.size(); i++)

{

ICallbackMetaData callbackMetadata = (ICallbackMetaData)messages.get(i);

String messageGuid = callbackMetadata.getMessageGUID();

messageGuids[i] = messageGuid;

System.err.println((new StringBuilder()).

append("recovering callback message =").

append(messageGuids[i]).append(" process[").

append(callbackMetadata.getProcessId()).append("(").

append(callbackMetadata.getRevisionTag()).

append(")] domain [").

append(callbackMetadata.getDomainId()).

append("]").toString());

}

Locator locator = getLocator();

IBPELDomainHandle domainHandle = locator.lookupDomain();

domainHandle.recoverCallbackMessages(messageGuids);

System.out.println("Complete RECOVER");

}

public String doRecover() throws Exception{

WhereCondition where = null;

// Connect to domain "default"

try{

System.out.println("doRecover() instantiating locator...");

Locator locator =(Locator) getLocator();

System.out.println("doRecover() instantiated locator for domain " +

locator.lookupDomain().getDomainId());

// look for Invoke messages in need of recovery

StringBuffer buf1 = new StringBuffer();

where = new WhereCondition(buf1.append(SQLDefs.IM_state).append( " = "

).append(IDeliveryConstants.STATE_UNRESOLVED ).toString() );

System.out.println("doRecover() instantiating IInvokeMetaData... with where = "+ where.getClause());

IInvokeMetaData imd1[] = locator.listInvokeMessages(where);

System.out.println("doRecover() instantiated IInvokeMetaData");

// iterate thru the list

List l1 = new ArrayList();

for (Object o:imd1){

l1.add(o);

}

// See how many INVOKES are in the recovery zone

System.out.println("doRecover() instantiated IInvokeMetaData size = " +l1.size());

// look for Callback messages in need of recovery

StringBuffer buf = new StringBuffer();

where = new WhereCondition(buf.append(SQLDefs.DM_state).append( " = "

).append(IDeliveryConstants.TYPE_callback_soap ).append(" and ").

append(SQLDefs.DM_conv_id).append(" = ").append("\'MD5{54017bc3a7bfc4f7f50381287ff28bc7}\'")

.append(SQLDefs.DM_process_id).append(" = ").append("\'BPELProcess3\'")

.append(" and ").append("ROWNUM").append(" < ").append("30").toString() );

System.out.println("doRecover() instantiating ICallbackMetaData... with where = "+

where.getClause());

ICallbackMetaData imd[] = locator.listCallbackMessages(where);

System.out.println("doRecover() instantiated ICallbackMetaData");

//

// recover

//

List l = new ArrayList();

for (Object o:imd){

l.add(o);

}

recoverCallbackMessages(l);

}

catch (Exception e){

e.printStackTrace();

}

return "done";

}

public Locator getLocator(){

System.out.println("getLocator() start");

Locator locator = null;

// set JNDI properties for BPEL lookup

String jndiProviderUrl = "opmn:ormi://127.0.0.1:6003:oc4j_soa/orabpel";

String jndiFactory = "com.evermind.server.rmi.RMIInitialContextFactory";

String jndiUsername = "oc4jadmin";

String jndiPassword = "welcome1";

Hashtable jndi = new Hashtable();

jndi.put(Context.PROVIDER_URL, jndiProviderUrl);

jndi.put(Context.INITIAL_CONTEXT_FACTORY, jndiFactory);

jndi.put(Context.SECURITY_PRINCIPAL, jndiUsername);

jndi.put(Context.SECURITY_CREDENTIALS, jndiPassword);

jndi.put("dedicated.connection", "true");

try{

System.out.println("getLocator() instantiating locator...");

locator = new Locator("default", jndi);

System.out.println("getLocator() instantiated locator@" +locator);

}

catch (Exception e){

System.out.println("getLocator() error");

e.printStackTrace();

}

return locator;

}

}