# Purpose

The Template Method pattern defines the skeleton of an algorithm in an operation, deferring some steps to subclasses.

# Problem

• Redundancy: Repetition of common logic across multiple classes processing nearly identical flows.

• Fragility: Difficulty ensuring that all variants follow the same control steps.

# Solution

Create a base class with a final method (the template) that invokes abstract methods. Subclasses fill in the blanks without changing the flow.

# Structure

# Participants

• AbstractClass: Defines the template and base steps.
• ConcreteClass: Implements specific steps of the algorithm.

# When to Use It

When you have a fixed recipe for a process but ingredients that change based on context or product type.

# Example: Drink Preparation

Common steps for Tea and Coffee (Boil, Pour) but specific preparation and ingredients for each.

# Java Code

abstract class DrinkTemplate {
    final void prepare() { boil(); brew(); pour(); }
    abstract void brew();
    void boil() { System.out.println("Boiling water"); }
    void pour() { System.out.println("Pouring into cup"); }
}

class Coffee extends DrinkTemplate {
    void brew() { System.out.println("Brewing coffee grounds"); }
}

class Tea extends DrinkTemplate {
    void brew() { System.out.println("Steeping the tea bag"); }
}

# Mapping Participants

• DrinkTemplate: AbstractClass.
• Tea/Coffee: ConcreteClasses.
• Client: Uses the DrinkTemplate's prepare method.

# Conclusions

Ensures that all subtypes of a process follow the same protocol, allowing clean and centralized specializations.

# Related Patterns