nAdminAPI code not returning current number of events in topic/queue

, ,
1

Hi All,

I am trying the below code to get the total number of events currently present in the topic/queue

String RNAME={realmUrl};
nSessionAttributes nsa=new nSessionAttributes(RNAME);
nRealmNode realm = new nRealmNode(nsa);

nNode nc=realm.findNode(destinationName);
nLeafNode myChannel=(nLeafNode) realm.findNode(destinationName);
Long evt = myChannel.getCurrentNumberOfEvents ();

evt is always coming as 0. Kindly suggest.

Regards
Abir Banerjee

2

Here you go:


                nSessionAttributes nsa = new nSessionAttributes(RNAME);
                nSession mySession=nSessionFactory.create(nsa);
		mySession.init();
                nChannelAttributes cattrib = new nChannelAttributes();
                cattrib.setName(destinationName);
                int numberOfEvents;
		int numberOfReaders;
		try{
			nQueue myQueue=mySession.findQueue(cattrib);
			nQueueDetails nqd = myQueue.getDetails();
			numberOfEvents=nqd.getNoOfEvents();
			numberOfReaders=nqd.getNoOfReaders();
		}
		catch(nChannelNotFoundException e){
			throw new ServiceException("Queue with name '"+queueName+"' does not exist");
		}
2 Likes
3

Thanks a lot Prasad for the details. I have another query. I am trying to use the code snippet provided in the UM document to list the topics and queues inside realm.

public void searchNodes(nContainer container)
Enumeration children = container.getNodes();
while (children.hasMoreElements()) {
nNode child = (nNode)children.nextElement();
if (child instanceof nContainer) {
searchNodes((nContainer)child);
} else if (child instanceof nLeafNode) {
nLeafNode leaf = (nLeafNode)child;
if (leaf.isChannel) {
System.out.println(“Leaf Node “+leaf.getName()+” is a channel”);
} else if (leaf.isQueue()) {
System.out.println(“Leaf Node “+leaf.getName()+” is a queue”);
}
}
}
}

The code is not working as it is showing class cast exception from String to nNode for the below line,

nNode child = (nNode)children.nextElement();

Is there any tweak for this. Kindly suggest.

Regards
Abir

4

Above code worked fine for me. Below is the outcome:

Coming to TWEAKS… as you are facing cast exception try to change your line as below:
CHANGE THIS LINE:

 nNode child = (nNode)children.nextElement();

TO:

 Object child = children.nextElement();
5

Thanks the tweak is working , but the issue is only the topics under JNDI topics are showing up , if a topic is like say “ext/temp/topics/testTopic” , these types of topics and queues are not showing up , that is nested ones.

6

Below is the code snippet that is used in the shared section of the java service

public static String searchQueues(nContainer container)
{
Enumeration children = container.getNodes();
String arr={“”};
StringBuilder sb=new StringBuilder(“”);
while (children.hasMoreElements()) {
nNode child = (nNode)children.nextElement();
if (child instanceof nContainer) {
searchQueues((nContainer)child);
} else if (child instanceof nLeafNode) {
nLeafNode leaf = (nLeafNode)child;
if (leaf.isQueue()) {
sb.append(leaf.getName());
sb.append(“\n”);
}
}
}
arr=sb.toString().split(“\n”);
return arr;
}

public static String[] searchTopics(nContainer container) 
{
	Enumeration children = container.getNodes(); 
	String arr[]={""};
	StringBuilder sb=new StringBuilder("");
	while (children.hasMoreElements()) { 
		nNode child = (nNode)children.nextElement(); 
		if (child instanceof nContainer) { 
				searchTopics((nContainer)child); 
		} else if (child instanceof nLeafNode) { 
				nLeafNode leaf = (nLeafNode)child; 
				if (leaf.isChannel()) { 
						sb.append(leaf.getName());
						sb.append("\n");
				} 
				} 
		} 
	arr=sb.toString().split("\n");
	return arr;
}

Now these methods are getting called as below

try
{
String RNAME={realmUrl};
nSessionAttributes nsa=new nSessionAttributes(RNAME);
nRealmNode realm = new nRealmNode(nsa);

		nContainer nc=(nContainer)realm;
		
		String topics[]=searchTopics(nc);
		String queues[]=searchQueues(nc);
		 
		
			
	}
	catch(Exception e)
	{
		errorMsg=e.toString();
	}

In the attached image , the topic , naming/defaultContext is not showing up in the result , for I believe when the Enum is getting listed , “naming” is not an instance of nContainer. Hence it is ignoring it. Kindly share your thoughts on this.

Regards
Abir Banerjee
Capture.JPG

7

Nope. “naming” is indeed an instance of nContainer. The issue you are facing might be because of a small code issue.

The below lines are local to “searchQueues/Topics” methods. The variables arr and sb will get created every time with a local scope during recursion. Because of this, all the queue names/topic names that are collected inside recursive call will not be propagated up to the call stack.

String arr[]={""}; 
StringBuilder sb=new StringBuilder("");

To fix this either make arr and sb as static fields in shared area or pass on these two into the searchX methods during recursion.

1 Like
8

Thanks Prasad , it is working now. Thanks for your suggestions.

Regards
Abir

9

Hi Prasad,

I am having issues with the static variables now. They are holding the reference from earlier calls . After compiling the code , when I am calling for first time , it is returning the correct number of topics and queues. Now if I am calling again , the values are getting duplicated , and if called again values are getting triplicated and so on…

Is there any way to remove the static variables after each call.

Regards
Abir Banerjee

10

Try below code:

try 
{ 
String[] RNAME={realmUrl}; 
nSessionAttributes nsa=new nSessionAttributes(RNAME); 
nRealmNode realm = new nRealmNode(nsa); 

nContainer nc=(nContainer)realm; 

StringBuilder queue_sb=new StringBuilder(); 
String queues[]=searchQueues(nc,queue_sb); 
 
StringBuilder topic_sb=new StringBuilder(); 
String topics[]=searchTopics(nc,topic_sb); 

} 
catch(Exception e) 
{ 
errorMsg=e.toString(); 
} 

public static String[] searchQueues(nContainer container, StringBuilder sb) 
{ 
String arr[]={""};
Enumeration children = container.getNodes(); 
while (children.hasMoreElements()) { 
nNode child = (nNode)children.nextElement(); 
if (child instanceof nContainer) { 
searchQueues((nContainer)child, sb); 
} else if (child instanceof nLeafNode) { 
nLeafNode leaf = (nLeafNode)child; 
if (leaf.isQueue()) { 
sb.append(leaf.getName()); 
sb.append("\n"); 
} 
} 
} 
arr=sb.toString().split("\n"); 
return arr; 
} 

public static String[] searchTopics(nContainer container, StringBuilder sb) 
{ 
Enumeration children = container.getNodes(); 
String arr[]={""}; 
while (children.hasMoreElements()) { 
nNode child = (nNode)children.nextElement(); 
if (child instanceof nContainer) { 
searchTopics((nContainer)child, sb); 
} else if (child instanceof nLeafNode) { 
nLeafNode leaf = (nLeafNode)child; 
if (leaf.isChannel()) { 
sb.append(leaf.getName()); 
sb.append("\n"); 
} 
} 
} 
arr=sb.toString().split("\n"); 
return arr; 
}
11

Hi Prasad,

Thanks for the details . I have tried another method which is sort of a band aid solution. :slight_smile: . I will try your method. What I did was,

//MAIN CODE SECTION//

StringBuilder qq=new StringBuilder(“”);
String queues={“”};

qq.append(searchQueues(nc));

queues=qq.toString().split(“\n”);
int qCap = sbQ.capacity(); ----> calculating the current capacity of the StringBuilder object
sbQ.delete(0, qCap); ----> deleting the contents of the StrinBuilder object after each call

//MAIN CODE SECTION//

//START SHARED CODE SECTION//
private static StringBuilder sbQ=new StringBuilder(“”);

public static StringBuilder searchQueues(nContainer container) 
{
	Enumeration children = container.getNodes(); 
	
	//String arr[]={""};
	//StringBuilder sb=new StringBuilder("");
	while (children.hasMoreElements()) { 
		nNode child = (nNode)children.nextElement(); 
		if (child instanceof nContainer) { 
				searchQueues((nContainer)child); 
		} else if (child instanceof nLeafNode) { 
				nLeafNode leaf = (nLeafNode)child; 
				if (leaf.isQueue()) { 
						//sbQ.append(leaf.getName());
						sbQ.append(leaf.getAbsolutePath ());
						sbQ.append("\n");
				} 
				} 
		} 
	
	return sbQ;
}

// END SHARED CODE SECTION //

12

Hi Prasad,

I am seeing that , when I am calling the nLeafNode methods to get the channel/topic properties I am not able to get the actual values like total publishes,total consumed etc. I am doing the code like this,

String RNAME={realmUrl};
nSessionAttributes nsa=new nSessionAttributes(RNAME);
nRealmNode realm = new nRealmNode(nsa);
nNode nn=realm.findNode(topicName);

nLeafNode nlf = (nLeafNode)nn;

		float connectionRate = nlf.getConnectionRate();
		float consumedRate = nlf.getConsumedRate();
		long currentConnections = nlf.getCurrentNoOfConnections();
		long totalConsumed = nlf.getTotalConsumed();
		long totalPublished = nlf.getTotalPublished();
		long usedSpace = nlf.getUsedSpace();
		nChannelAttributes nch = nlf.getAttributes();
		long ttl=nch.getTTL();
		int type=nch.getType ();

Here only getTTL and type are giving the proper values , the total consumed and total published are not providing correct values only returning 0.

Regards
Abir Banerjee

13

I never tried reading those kind of fields using nLeafNode. Like I posted early in this topic, I prefer going with nQueue or nChannel kind of classes where I got results desired. Once again, below is a sample code to read “noOfEvents” and “noOfReader (connections)”.

You may explore other methods of nQueueDetails and see if it has got the details you are looking for.

nSessionAttributes nsa = new nSessionAttributes(RNAME);  
              nSession mySession=nSessionFactory.create(nsa);  
mySession.init();  
              nChannelAttributes cattrib = new nChannelAttributes();  
              cattrib.setName(destinationName);  
              int numberOfEvents;  
int numberOfReaders;  
try{  
    nQueue myQueue=mySession.findQueue(cattrib);  
    nQueueDetails nqd = myQueue.getDetails();  
    numberOfEvents=nqd.getNoOfEvents();  
    numberOfReaders=nqd.getNoOfReaders();  
}  
catch(nChannelNotFoundException e){  
    throw new ServiceException("Queue with name '"+queueName+"' does not exist");  
}
14

Hi all,

I have a slightly different issue, when I run this to connect:


nSessionAttributes nsa=new nSessionAttributes(RNAME);
nRealmNode realm = new nRealmNode(nsa);

I get the following exception:

Exception in thread "main" java.lang.NoClassDefFoundError: com/pcbsys/nirvana/client/p2p/nServiceFactory
	at com.pcbsys.nirvana.nAdminAPI.nRealmNode.loadChannels(nRealmNode.java:3787)
	at com.pcbsys.nirvana.nAdminAPI.nRealmNode.createNameSpace(nRealmNode.java:3669)
	at com.pcbsys.nirvana.nAdminAPI.nRealmNode.connectToRealm(nRealmNode.java:3447)
	at com.pcbsys.nirvana.nAdminAPI.nRealmNode.create(nRealmNode.java:1389)
	at com.pcbsys.nirvana.nAdminAPI.nRealmNode.<init>(nRealmNode.java:1385)
	at com.pcbsys.nirvana.nAdminAPI.nRealmNode.<init>(nRealmNode.java:1371)
	at com.pcbsys.nirvana.nAdminAPI.nRealmNode.<init>(nRealmNode.java:1359)

I suspect that it is a version issue, it will help if I get the nClient.jar and nAdminAPI.jar that you guys are using.

Can you please assist me?

Regards,
Patrick