30 lines
1.5 KiB
Markdown
30 lines
1.5 KiB
Markdown
# Template Method Design Pattern — Java Example
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**Pattern:** Behavioral → Template Method
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**Article:** https://ankurm.com/template-method-design-pattern-java/
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## What this example shows
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A data migration pipeline with a fixed skeleton and variable steps. `DataMigration` declares `migrate()` as `final` — the sequence (connect, validate, read, transform, write, notify, disconnect) can never be reordered or skipped by a subclass. `getSourceName()`, `connect()`, `readData()`, and `transformData()` are abstract steps each subclass must supply; `validate()`, `writeData()`, and `disconnect()` are concrete steps shared by everyone; `sendNotification()` is a hook with a default of `true` that a subclass can override. `CsvMigration` uses every default unchanged. `ApiMigration` overrides the hook to stay silent. `Main` runs both through the identical skeleton.
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## How to run
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```bash
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javac template-method/*.java -d out/template-method
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java -cp out/template-method template.Main
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```
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Requires Java 25.
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## Post Section ↔ File Mapping
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| Post Section | File(s) |
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| Implementation: Data Migration Pipeline — the abstract class & template method | `DataMigration.java` |
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| Implementation: Data Migration Pipeline — CsvMigration | `CsvMigration.java` |
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| Implementation: Data Migration Pipeline — ApiMigration | `ApiMigration.java` |
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| Implementation: Data Migration Pipeline — wiring it together | `Main.java` |
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Article: https://ankurm.com/template-method-design-pattern-java/
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All patterns: https://ankurm.com/design-patterns-java/
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