69 lines
1.6 KiB
Go
69 lines
1.6 KiB
Go
package main
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import "fmt"
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/*
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实例：
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汤宝宝买火车票，可以去火车站买，也可以去代售点买，但是汤宝宝选择全都要。然而，火车站总共只剩两张票，这可苦了小明了。
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*/
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type Seller interface {
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Sell(name string) error
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}
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type TrainStation struct {
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stock int
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}
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func newTrainStation(stock int) *TrainStation {
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fmt.Printf("火车站库存%d张票\n", stock)
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return &TrainStation{stock: stock}
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}
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func (ts *TrainStation) Sell(name string) error {
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fmt.Printf("%s去火车站买票。\n", name)
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if ts.stock > 0 {
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ts.stock--
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fmt.Printf("%s在火车站买到一张火车票。\n", name)
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return nil
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} else {
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fmt.Printf("火车站没有票了, %s没买到票。\n", name)
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return fmt.Errorf("no ticket")
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}
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}
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type TicketAgency struct {
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name string
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station *TrainStation
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}
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func newTicketAgency(name string, station *TrainStation) *TicketAgency {
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return &TicketAgency{name: name, station: station}
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}
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func (tp *TicketAgency) Sell(name string) error {
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fmt.Printf("%s去%s买票。\n", name, tp.name)
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err := tp.station.Sell(tp.name)
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if err != nil {
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fmt.Printf("%s在%s没买到票。\n", name, tp.name)
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return err
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}
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fmt.Printf("%s在%s买到一张火车票。\n", name, tp.name)
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return nil
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}
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func main() {
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fmt.Println("============= 代理模式 =============")
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station := newTrainStation(2)
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agency := newTicketAgency("代售点A", station)
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station.Sell("汤宝宝")
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agency.Sell("汤宝宝")
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fmt.Println()
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agency.Sell("小明")
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station.Sell("小明")
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fmt.Println()
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fmt.Println("=========== 代理模式结束 ===========")
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}
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