模式定义
将一个申请（行为）封装为一个对象，从而使你可用不同的申请对客户进行参数化，对申请排队或记录申请日志，以及反对可撤销的操作
类图
要点总结
- Command 模式的基本目标在于将“行为请求者”与“行为实现者”解耦，在面向对象语言中，常见的实现伎俩是“将行为形象为对象”
- 实现 Command 接口的具体命令对象 ConcreteCommand 有时候依据须要可能会保留一些额定的状态信息，通过应用 Composite 模式，能够将多个“命令”封装为一个“复合命令”MacroCommand
Go 语言代码实现
工程目录
command.go
package Command
import "fmt"
type Person struct {
name string
cmd Command
}
type Command struct {
person *Person
method func()}
func NewCommand (p *Person, method func()) Command {
return Command{
person: p,
method: method,
}
}
func (c *Command) Execute(){c.method()
}
func NewPerson (name string, cmd Command) Person{
return Person{
name: name,
cmd: cmd,
}
}
func (p *Person) Buy() {fmt.Println(fmt.Sprintf("%s is buying", p.name))
p.cmd.Execute()}
func (p *Person) Cook() {fmt.Println(fmt.Sprintf("%s is cooking", p.name))
p.cmd.Execute()}
func (p *Person) Wash() {fmt.Println(fmt.Sprintf("%s is washing", p.name))
p.cmd.Execute()}
func (p *Person) Listen() {fmt.Println(fmt.Sprintf("%s is listening", p.name))
p.cmd.Execute()}
func (p *Person) Talk() {fmt.Println(fmt.Sprintf("%s is talking", p.name))
p.cmd.Execute()}command_test.go
package Command
import "testing"
func TestCommand_Execute(t *testing.T) {laowang := NewPerson("wang", NewCommand(nil, nil))
laozhang := NewPerson("zhang", NewCommand(&laowang, laowang.Listen))
laofeng := NewPerson("feng", NewCommand(&laozhang, laozhang.Buy))
laoding := NewPerson("ding", NewCommand(&laofeng, laofeng.Cook))
laoli := NewPerson("li", NewCommand(&laoding, laoding.Wash))
laoli.Talk()}