组合设计模式
简介
将对象组合成树形结构以表示“部分-整体”的层次结构。组合设计模式使得用户对单个对象和组合对象的使用具有一致性。
参与者
-
Component
为组合中的对象声明接口
-
Leaf
在组合中表示叶子节点对象。
-
Composite
存储子部件。访问和管理子部件。
案例1
component.go
package main
type Component interface {
Execute()
}
leaf.go
package main
import "fmt"
type Leaf struct {
name string
}
func (l *Leaf) Execute() {
fmt.Printf("%s leaf execute\n", l.name)
}
composite.go
package main
import "fmt"
type Composite struct {
name string
components []Component
}
func (cm *Composite) Execute() {
fmt.Printf("%s composite execute\n", cm.name)
for _, c := range cm.components {
c.Execute()
}
}
func (cm *Composite) Add(component Component) {
cm.components = append(cm.components, component)
}
client.go
package main
func main() {
composite1 := &Composite{name: "composite1"}
composite2 := &Composite{name: "composite2"}
leaf1 := &Leaf{name: "leaf1"}
leaf2 := &Leaf{name: "leaf2"}
leaf3 := &Leaf{name: "leaf3"}
composite2.Add(composite1)
composite1.Add(leaf1)
composite2.Add(leaf2)
composite2.Add(leaf3)
composite2.Execute()
}