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 maintype Component interface {Execute()
}

leaf.go

package mainimport "fmt"type Leaf struct {name string
}func (l *Leaf) Execute() {fmt.Printf("%s leaf execute\n", l.name)
}

composite.go

package mainimport "fmt"type Composite struct {name       stringcomponents []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 mainfunc 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()
}