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The main difference between the **Adapter** and a **wrapper class** lies in their **purpose** and **level of abstraction**:
all adapters are wrappers, but **not every wrapper is an adapter**.

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### 1. **Purpose**

- **Adapter** solves the **architectural task of interface compatibility**: it lets an object with a "wrong" interface work where a different one is expected.
- **Wrapper** simply **adds functionality** around an existing object (for example, logging, validation, caching) without changing the interface.

**Example:**

- Adapter: turns `playMP3()` into `play(String file)`: "translates" the interface.
- Wrapper: adds logging to `play(String file)`: "extends" the behavior.

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### 2. **Interface**

- **Adapter** usually **changes the interface**: it implements one (target) interface and calls methods of another (adapted) one.
- **Wrapper** **keeps the same interface**, simply wrapping calls with extra logic.

**Example (Adapter):**

```java
class MediaAdapter implements MediaPlayer {
    private OldPlayer player = new OldPlayer();
    public void play(String file) { player.startPlayback(file); }
}
```

**Example (Wrapper):**

```java
class LoggingMediaPlayer implements MediaPlayer {
    private MediaPlayer wrapped;
    public void play(String file) {
        System.out.println("Start playing " + file);
        wrapped.play(file);
    }
}
```

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### 3. **Context of Use**

| Criterion | Adapter | Wrapper |
|---|---|---|
| Purpose | Interface compatibility | Behavior extension |
| Changes the interface | Yes | No |
| Example use case | Integrating old and new code | Adding logging, caching |
| Level | Architectural | Behavioral |

---

### 4. **Conclusion**

Adapter is an **"interface translator"** that ensures compatibility.
Wrapper is a **"behavior decorator"** that adds new capabilities without changing the contract.
In other words, Adapter is needed to **connect the incompatible**, while Wrapper is needed to **reinforce what is already compatible**.

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