spring增强访问者模式-改造后

src/main/java/top/fjy8018/designpattern/pattern/behavior/visitor/spring/after/DrawVisitor.java

@@ -0,0 +1,34 @@
+package top.fjy8018.designpattern.pattern.behavior.visitor.spring.after;
+
+import top.fjy8018.designpattern.pattern.behavior.visitor.spring.bean.Building;
+import top.fjy8018.designpattern.pattern.behavior.visitor.spring.bean.Factory;
+import top.fjy8018.designpattern.pattern.behavior.visitor.spring.bean.Node;
+import top.fjy8018.designpattern.pattern.behavior.visitor.spring.bean.School;
+
+/**
+ * TODO:
+ *
+ * @author F嘉阳
+ * @date 2022/1/26 10:31
+ */
+public class DrawVisitor implements Visitor {
+	@Override
+	public void visit(Node node) {
+		System.out.println("draw node");
+	}
+
+	@Override
+	public void visit(Factory factory) {
+		System.out.println("draw factory");
+	}
+
+	@Override
+	public void visit(Building building) {
+		System.out.println("draw building");
+	}
+
+	@Override
+	public void visit(School school) {
+		System.out.println("draw school");
+	}
+}

src/main/java/top/fjy8018/designpattern/pattern/behavior/visitor/spring/after/Visitor.java

@@ -0,0 +1,23 @@
+package top.fjy8018.designpattern.pattern.behavior.visitor.spring.after;
+
+import top.fjy8018.designpattern.pattern.behavior.visitor.spring.bean.Building;
+import top.fjy8018.designpattern.pattern.behavior.visitor.spring.bean.Factory;
+import top.fjy8018.designpattern.pattern.behavior.visitor.spring.bean.Node;
+import top.fjy8018.designpattern.pattern.behavior.visitor.spring.bean.School;
+
+/**
+ * Visitor Pattern
+ *
+ * @author F嘉阳
+ * @date 2022/1/26 10:31
+ */
+public interface Visitor {
+
+	void visit(Node node);
+
+	void visit(Factory factory);
+
+	void visit(Building building);
+
+	void visit(School school);
+}

src/main/java/top/fjy8018/designpattern/pattern/behavior/visitor/spring/bean/Building.java

@@ -1,5 +1,7 @@
 package top.fjy8018.designpattern.pattern.behavior.visitor.spring.bean;
 
+import top.fjy8018.designpattern.pattern.behavior.visitor.spring.after.Visitor;
+
 /**
  * TODO:
  *
@@ -16,4 +18,13 @@ public class Building implements Node {
 	public String getDescription() {
 		return null;
 	}
+
+	/**
+	 * 调用方知道visit的参数就是Building类型的，并且知道Visitor::visit(Building)方法确实存在，
+	 * 因此会直接调用Visitor::visit(Building)方法
+	 */
+	@Override
+	public void accept(Visitor v) {
+		v.visit(this);
+	}
 }

src/main/java/top/fjy8018/designpattern/pattern/behavior/visitor/spring/bean/Factory.java

@@ -1,5 +1,7 @@
 package top.fjy8018.designpattern.pattern.behavior.visitor.spring.bean;
 
+import top.fjy8018.designpattern.pattern.behavior.visitor.spring.after.Visitor;
+
 /**
  * TODO:
  *
@@ -16,4 +18,13 @@ public class Factory implements Node {
 	public String getDescription() {
 		return null;
 	}
+
+	/**
+	 * 调用方知道visit的参数就是Factory类型的，并且知道Visitor::visit(Factory)方法确实存在，
+	 * 因此会直接调用Visitor::visit(Factory)方法
+	 */
+	@Override
+	public void accept(Visitor v) {
+		v.visit(this);
+	}
 }

src/main/java/top/fjy8018/designpattern/pattern/behavior/visitor/spring/bean/Node.java

@@ -1,5 +1,7 @@
 package top.fjy8018.designpattern.pattern.behavior.visitor.spring.bean;
 
+import top.fjy8018.designpattern.pattern.behavior.visitor.spring.after.Visitor;
+
 /**
  * 地图节点
  *
@@ -11,4 +13,6 @@ public interface Node {
 	String getName();
 
 	String getDescription();
+
+	void accept(Visitor v);
 }

src/main/java/top/fjy8018/designpattern/pattern/behavior/visitor/spring/bean/School.java

@@ -1,5 +1,7 @@
 package top.fjy8018.designpattern.pattern.behavior.visitor.spring.bean;
 
+import top.fjy8018.designpattern.pattern.behavior.visitor.spring.after.Visitor;
+
 /**
  * TODO:
  *
@@ -16,4 +18,13 @@ public class School implements Node {
 	public String getDescription() {
 		return null;
 	}
+
+	/**
+	 * 调用方知道visit的参数就是School类型的，并且知道Visitor::visit(School)方法确实存在，
+	 * 因此会直接调用Visitor::visit(School)方法
+	 */
+	@Override
+	public void accept(Visitor v) {
+		v.visit(this);
+	}
 }

src/main/java/top/fjy8018/designpattern/pattern/behavior/visitor/spring/before/DrawService.java

@@ -1,4 +1,4 @@
-package top.fjy8018.designpattern.pattern.behavior.visitor.spring;
+package top.fjy8018.designpattern.pattern.behavior.visitor.spring.before;
 
 import top.fjy8018.designpattern.pattern.behavior.visitor.spring.bean.Building;
 import top.fjy8018.designpattern.pattern.behavior.visitor.spring.bean.Factory;

src/test/java/top/fjy8018/designpattern/pattern/behavior/visitor/spring/DrawServiceTest.java

@@ -2,10 +2,13 @@ package top.fjy8018.designpattern.pattern.behavior.visitor.spring;
 
 import lombok.extern.slf4j.Slf4j;
 import org.junit.jupiter.api.Test;
+import top.fjy8018.designpattern.pattern.behavior.visitor.spring.after.DrawVisitor;
+import top.fjy8018.designpattern.pattern.behavior.visitor.spring.after.Visitor;
 import top.fjy8018.designpattern.pattern.behavior.visitor.spring.bean.Building;
 import top.fjy8018.designpattern.pattern.behavior.visitor.spring.bean.Factory;
 import top.fjy8018.designpattern.pattern.behavior.visitor.spring.bean.Node;
 import top.fjy8018.designpattern.pattern.behavior.visitor.spring.bean.School;
+import top.fjy8018.designpattern.pattern.behavior.visitor.spring.before.DrawService;
 
 /**
  * DrawService中只有4个draw方法，参数类型分别是Factory, Building, School和Node，如果调用方传了一个City进来怎么办？
@@ -26,6 +29,13 @@ class DrawServiceTest {
 		draw(new Factory());
 	}
 
+	@Test
+	public void draw2() {
+		Visitor drawVisitor = new DrawVisitor();
+		Factory factory = new Factory();
+		factory.accept(drawVisitor);
+	}
+
 	private void draw(Node node) {
 		DrawService drawService = new DrawService();
 		if (node instanceof Building) {