Java Design Patterns

Java Design Patterns — a practical guide to Java design patterns with clear examples you can reuse in real projects.

Java Tutorial Series (85/90). Prefer one article? Read the complete Java tutorial.

Short description

Patterns communicate design intent. Use them where they reduce complexity, not for decoration.

Builder sketch

class User {
    final String name;
    final String email;
    private User(Builder b) { name = b.name; email = b.email; }
    static class Builder {
        String name, email;
        Builder name(String n) { name = n; return this; }
        Builder email(String e) { email = e; return this; }
        User build() { return new User(this); }
    }
}