State Pattern Use Cases and Examples in Java

State is strongest where lifecycle is central to the model.

Strong Java Use Cases

• orders that move from pending to paid to shipped
• connections that move through open, closed, reconnecting, and failed states
• UI workflows with distinct editing, reviewing, and locked modes
• approval pipelines with different allowed actions per stage

Weak Java Use Cases

State is weak when:

• the lifecycle is tiny and unlikely to grow
• only one method really changes behavior
• conditionals remain few and readable

Use State when status-dependent behavior is important enough to deserve its own explicit model.