Example: Using the correlation service interface

Consult this information when utilizing the ARM API with the correlation service as part of a servlet instrumentation.

Example

The following example illustrates one of the typical workflows of using the ARM API in conjunction with the correlation service as part of a servlet instrumentation:

public void doGet(HttpServletRequest request, HttpServletResponse response)
  throws ServletException, IOException {

PmiRmArmTx artrax =
// The factory detects the currently active ARM implementation (specified by user through 
// admin console) and instantiates an appropriate ARM wrapper object 
    PmiRmArmTxFactory.createPmiRmArmTx();
ArmTransaction at = newArmTx();
if (null == at)
            out.println("Got a null ArmTransaction");
ArmCorrelator arc = newArmCorr();
at.start(arc);
try {
 artrax.setArmTransaction(at);
 PmiRmArmStack.pushTransaction(artrax);
} catch (Exception e) {
 System.out.println("Caught 1 exception" + e);
}

PmiRmArmTx atxwrp = PmiRmArmStack.peekTransaction();

if (atxwrp == null)
 out.println("Armtransaction is null");

//getArmType try {
 out.println("ARMTYPE is"+ PmiRmArmTx.getARMType());
} catch (Exception e) {
 out.println(e);
}
//getting correlator bytes try {
 if (null == atxwrp.getCorrelatorBytes())
  out.println("Got a null Correlator");
} catch (Exception e) {
 out.println(e);
}

//blocked/unblocked long blkid = 0;
try {
 out.println(blkid = atxwrp.blocked());
} catch (Exception e) {
 out.println(e);
}

try {
 out.println(atxwrp.unblocked(blkid));
} catch (Exception e) {
 out.println(e);
}
try {
 atxwrp = PmiRmArmStack.popTransaction();
 ArmTransaction art = (ArmTransaction) atxwrp.getArmTransaction();
 art.stop(ArmConstants.STATUS_GOOD);
} catch (Exception e) {
 out.println(e);
}

}



private ArmTransaction newArmTx() {

 ArmTransactionFactory txFactory = null;
try {
 String sWasName = "WebSphere";
 String appName = "t23xpimage/t23xpimage/server1";
 String sCellName = appName.substring(0, appName.indexOf("/"));
 String sNodeInstance =
   appName.substring(appName.indexOf("/") + 1, appName.length());
 sNodeInstance = sNodeInstance.replace('/', '.');
 txFactory = (ArmTransactionFactory)                   
newObjectInstance("org.opengroup.arm40.sdk.ArmTransactionFactoryImpl");
 ArmApplication app = null; // 149297
 ArmApplicationDefinition appDef = null; //LIDB3207
 appDef =    txFactory.newArmApplicationDefinition(sWasName, null, null);
 app = txFactory.newArmApplication(appDef, sCellName, sNodeInstance, null);

 String[] idnames = { "request_type" };
 String[] idvalues = { "URI" };
 String[] ctxnames = { "URI" };
 ArmIdentityPropertiesTransaction props =
   txFactory.newArmIdentityPropertiesTransaction(
     idnames,
     idvalues,
     ctxnames,
     null);
 ArmTransactionDefinition atd =
    txFactory.newArmTransactionDefinition(
     appDef,
     "URI",
     props,
     (ArmID) null);
 ArmTransaction at = txFactory.newArmTransaction(app, atd);
 return at;
} catch (Exception e) {
 System.out.println(e);
 return null;
}

}

private ArmCorrelator newArmCorr() {

 ArmTransactionFactory txFactory = null;
try {
 String sWasName = "WebSphere";
 String appName = "t23xpimage/t23xpimage/server1";
 txFactory =
 (ArmTransactionFactory) 
newObjectInstance("org.opengroup.arm40.sdk.ArmTransactionFactoryImpl");

 ArmCorrelator arc =txFactory.newArmCorrelator(
     PmiRmArmStack.peekTransaction().getCorrelatorBytes());
 return arc;
} catch (Exception e) {
 System.out.println(e);
 return null;
}

}

ExampleThere are several potential scenarios for using the PmiRmArmStack. This example shows a scenario where code accesses an existing PmiRmArmTx on the stack, extracts the correlator, and calls blocked and unblocked. This is a typical scenario when sending a correlator along an unsupported protocol. In this scenario, the Arm transaction is already on the stack.

1   PmiRmArmTx artrax =
2    PmiRmArmStack.peekTransaction();
3   if( artrax != null )
4                         {
5                                     try 6                                     {
7        byte[] cbytes = artrax.getCorrelatorBytes();
8                                         stuffBytesIntoOutboundMessage( msg, cbytes);
9                                          long blockedId = 0;
10                                         try 11                                         {
12                                            blockedId = artrax.blocked();
13                                          }
14                                          catch( NoSuchMethodException nsme )
15                                          {
16                                              // must not be running ARM4 or eWLM
17                                          }
18                                            sendMsg( msg );
19                                         try 20                                         {
21                                            artrax.blocked( blockedId );
22                                          }
23                                          catch( NoSuchMethodException nsme )
24                                          {
25                                              // must not be running ARM4 or eWLM
26                                          }
27                     
28                                      }
29                                      catch( Exception e )
30                                      {
31                                         report a problem;
32                                      }
33   }
 

Related concepts

Searchable topic ID: rprf_excorrserv