Composite is the structural pattern for part-whole hierarchies. In Java, it becomes useful when the client should not care whether it is dealing with one object or a tree of objects.
Typical examples include:
- UI component trees
- file or folder structures
- product bundles
- rule groups
- scene graphs
Composite is powerful because it gives recursive structure a uniform API. It is dangerous because once the tree is public, ownership, mutation, and traversal rules must be designed carefully.
In this section
- Implementing Composite in Java
Implement Composite in Java with a clear component contract, disciplined child ownership, and traversal rules that fit recursive structures.
- Component, Leaf, and Composite Classes
Design the three Composite roles in Java deliberately so the shared contract stays useful and child-management rules stay explicit.
- Managing Hierarchical Structures with the Composite Pattern
Manage Java composite hierarchies with explicit ownership, cycle rules, mutation boundaries, and aggregation semantics.
- Iteration and Recursion in Composites
Choose traversal style for Java composites deliberately, balancing recursion, explicit iterators, streams, and failure handling.
- Composite Pattern Use Cases and Examples in Java
See where Composite earns its place in Java systems, especially UI trees, file-like hierarchies, bundles, and recursive rule structures.