The WeakReference class, monitoring memory leak and garbage collection in a Java application

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Image
 Below is a Stack implementation that uses an internal resizeable array structure.  public class MyStack< T > implements Stack< T > { private static final int CAPACITY = 100 ; private Object[] array ; private int pos = 0 ; public MyStack () { this . array = new Object[ CAPACITY ] ; } @Override public void push ( T item) { if ( pos >= array . length / 2 ) { Object[] newArray = new Object[ pos * 2 ] ; System. arraycopy ( array , 0 , newArray , 0 , array . length ) ; array = newArray ; } array [ pos ++] = item ; } @Override public T pop () { if (isEmpty()) { throw new RuntimeException( "empty stack" ) ; } @SuppressWarnings ( "unchecked" ) T item = ( T ) array [ pos - 1 ] ; pos -= 1 ; return item ; } @Override @SuppressWarnings ( "unchecked" ) public T peek...
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nijhof2axon

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Axon framework kullanıcılarına katkıda bulunmak amacıyla paylaştığım proje ile ilgili yorum ve sorular gelmeye başladı.

http://code.google.com/p/nijhof2axon/

>>You share the Data between the Domain and the Query Model?
When a command is dispatched, a CommandHandler uses the aggregate root to handle the command. Aggregate root fires DomainEvents.
=> Query layer related code listens to domain events and updates the query model. (Example: ClientTableUpdater)

Domain entities are first class objects but Query Model classes are just DTOs with getters and setters. We have Client as entity and ClientDetailsEntry as DTO.

>>The (generated?) table domainevententry looks like you can not replay events? missing the event data?

To observe how events are replayed by the framework, you can follow these steps:

Click on sample client
change name
stop server
start server
put a breakpoint to EventSourcingRepository.doLoad() method
put a breakpoint to Client.handleClientNameChangedEvent() method
start server in debug mode
open the client that you changed
change name
=> you stop at the doLoad() breakpoint
reach to this line:
aggregate.initializeState(...
Here the events will be replayed to initialize aggregate state.
=> hit the breakpoint of Client.handleClientNameChangedEvent()

So, we have to implement the handlers that handle state changes properly.

>>if i can force the query database to have a invalid state...
You can do that by not listening to domain events and not updating query tables. So updating the query tables properly is our duty.

>>how to replay events to integrate new features
I added a test class to nijhof2axon. Please have a look at SampleEventVisitorTest

>>how i can monitor the system (maybe the command and event queue)
We can look at org.axonframework.auditing.AuditingInterceptor

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