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docs: update visitor

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Ilkka Seppälä committed 2024-05-27 14:59:50 +03:00
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commit 2bbf893133
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visitor/README.md
+33 -15
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@@ -50,6 +50,9 @@ public abstract class Unit {
} }
} }
```
```java
public interface UnitVisitor { public interface UnitVisitor {
void visit(Soldier soldier); void visit(Soldier soldier);
@@ -80,7 +83,9 @@ public class Commander extends Unit {
return "commander"; return "commander";
} }
} }
```
```java
public class Sergeant extends Unit { public class Sergeant extends Unit {
public Sergeant(Unit... children) { public Sergeant(Unit... children) {
@@ -98,7 +103,9 @@ public class Sergeant extends Unit {
return "sergeant"; return "sergeant";
} }
} }
```
```java
public class Soldier extends Unit { public class Soldier extends Unit {
public Soldier(Unit... children) { public Soldier(Unit... children) {
@@ -139,7 +146,9 @@ public class CommanderVisitor implements UnitVisitor {
LOGGER.info("Good to see you {}", commander); LOGGER.info("Good to see you {}", commander);
} }
} }
```
```java
@Slf4j @Slf4j
public class SergeantVisitor implements UnitVisitor { public class SergeantVisitor implements UnitVisitor {
@@ -158,7 +167,9 @@ public class SergeantVisitor implements UnitVisitor {
// Do nothing // Do nothing
} }
} }
```
```java
@Slf4j @Slf4j
public class SoldierVisitor implements UnitVisitor { public class SoldierVisitor implements UnitVisitor {
@@ -182,23 +193,30 @@ public class SoldierVisitor implements UnitVisitor {
Finally, we can show the power of visitors in action. Finally, we can show the power of visitors in action.
```java ```java
commander.accept(new SoldierVisitor()); public static void main(String[] args) {
commander.accept(new SergeantVisitor());
commander.accept(new CommanderVisitor()); var commander = new Commander(
new Sergeant(new Soldier(), new Soldier(), new Soldier()),
new Sergeant(new Soldier(), new Soldier(), new Soldier())
);
commander.accept(new SoldierVisitor());
commander.accept(new SergeantVisitor());
commander.accept(new CommanderVisitor());
}
``` ```
Program output: Program output:
``` ```
Greetings soldier 14:58:06.115 [main] INFO com.iluwatar.visitor.SoldierVisitor -- Greetings soldier
Greetings soldier 14:58:06.118 [main] INFO com.iluwatar.visitor.SoldierVisitor -- Greetings soldier
Greetings soldier 14:58:06.118 [main] INFO com.iluwatar.visitor.SoldierVisitor -- Greetings soldier
Greetings soldier 14:58:06.118 [main] INFO com.iluwatar.visitor.SoldierVisitor -- Greetings soldier
Greetings soldier 14:58:06.118 [main] INFO com.iluwatar.visitor.SoldierVisitor -- Greetings soldier
Greetings soldier 14:58:06.118 [main] INFO com.iluwatar.visitor.SoldierVisitor -- Greetings soldier
Hello sergeant 14:58:06.118 [main] INFO com.iluwatar.visitor.SergeantVisitor -- Hello sergeant
Hello sergeant 14:58:06.118 [main] INFO com.iluwatar.visitor.SergeantVisitor -- Hello sergeant
Good to see you commander 14:58:06.118 [main] INFO com.iluwatar.visitor.CommanderVisitor -- Good to see you commander
``` ```
## Class diagram ## Class diagram
@@ -215,9 +233,9 @@ Use the Visitor pattern when
## Tutorials ## Tutorials
* [Visitor - Refactoring Guru](https://refactoring.guru/design-patterns/visitor) * [Visitor (Refactoring Guru)](https://refactoring.guru/design-patterns/visitor)
* [Visitor Pattern Tutorial with Java Examples - DZone](https://dzone.com/articles/design-patterns-visitor) * [Visitor Pattern Tutorial with Java Examples (DZone)](https://dzone.com/articles/design-patterns-visitor)
* [Visitor Design Pattern - Sourcemaking](https://sourcemaking.com/design_patterns/visitor) * [Visitor Design Pattern (Sourcemaking)](https://sourcemaking.com/design_patterns/visitor)
## Known uses ## Known uses
visitor/src/main/java/com/iluwatar/visitor/App.java
-1
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@@ -48,6 +48,5 @@ public class App {
commander.accept(new SoldierVisitor()); commander.accept(new SoldierVisitor());
commander.accept(new SergeantVisitor()); commander.accept(new SergeantVisitor());
commander.accept(new CommanderVisitor()); commander.accept(new CommanderVisitor());
} }
} }