Heap introspection for test puposes
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Latest commit e4c47e6 Jun 12, 2017



Test library to introspecting your Java heap via heap dumps.

HeapUnit can

  • capture heap dump of own JVM
  • scan content of dump
  • reconstruct Java objects from heap dump


Code snippet below dumps TCP Socket instances found in heap

HeapImage hi = HeapUnit.captureHeap();
for(HeapInstance i: hi.instances(SocketImpl.class)) {
	// fd field in SocketImpl class is nullified when socket gets closed
	boolean open = i.value("fd") != null;
	System.out.println(i.rehydrate() + (open ? " - open" : " - closed"));

Full source is here

Maven artifact

HeapUnit and dependencies is available in Maven Central Repo