Because Your Data Is Worth It

  • Live Container Instances

    Every Live container in the heap is tracked. Views organize them neatly in their interface groups (Maps, Lists, Sets, Queues, etc...)

  • Live Animated Container API Usage

    Any API called lights up and increments the counter at the intersection of API column and container instance row.

  • Container Population Chart

    Track the evolution in time of your container populations. See when instance creation hotspots are active.

  • Class Relationship Tree


    Visualizes the role relationships between container class,element class and container user class. All sensible relationship permutations can be viewed (eg user/element/container or container/element/user).


  • Class Loading

    All classes loaded by the profiled application are logged and charted with full timestamp and ClassLoader information.

  • Launch Dialog

    CollectionSpy lets you define any number of target applications to profile, along with their launching parameters, such as JRE to use, command line flags to use, and so on.

Profile any Java Program to Analyse Collection Framework Usage

Profile client or server applications and discover how, where and when your program uses the Java Collection Framework containers.

View the Content of any Map, List, Set or Queue

Effortlessly view and browse the content of any container at any time. Map content views, show key, value pairs without burdening you with the time-consuming and sometimes maze-like intricate details of implementation-specific supporting data structures. Hashing container content views feature extra information on actual element or key hashCodes.

Analysis Rules Detect a Variety of Bugs and Coding Anti-Patterns

Runtime Analysis Rules detect bugs and usage anti-patterns that are impossible to detect by classic static code analysis tools like CheckStyle, PMD or even FindBugs. CollectionSpy Analysis Rules address anti-patterns and bugs that lead to container and/or data corruption due to flawed concurrent coding, wasted heap usage and reduced performance.

View Complete Hash Code Distribution of Any Hashing Container

Hash table performance problems are a thing of the past with CollectionSpy as problems are instantly diagnosed by the hash code collision and distribution visualization feature.

Realtime Display of All Containers in the Heap

Live view of all containers, along with a wealth of dynamic statistics like container size, element type(s), thread accesses, detailed API usage, and much more.

View Live, Animated Container API Usage

Find out what methods are being called on which container. For any method call, CollectionSpy can show you which logic triggered the method in the form of stack traces.

See Which Threads Access Which Containers

Instantly see the causes of corruption due to concurrent thread modifications of shared containers.

See Which Code Uses Which Collection Framework Aspects

CollectionSpy's unique Usage Radar lets you quickly see which of your packages, classes and methods use which parts of the Collection Framework.

Realtime Container Corruption Detection

Notifies you when any hashing container becomes corrupted due to a mutable key (for Maps) or element (for non-Maps) gets mutated while part of a container.

Interoperates with Your Favourite IDE

Whether you prefer Eclipse, Netbeans or IntelliJ, CollectionSpy will use your favourite IDE whenever you drill-down to source code level.