GO语言（六）接口使用
作者：互联网
原文链接：http://www.cnblogs.com/xuxu8511/p/3312063.html
<music>
|------<src>
|-------<library>
|-------manager.go
|-------manager_test.go
|-------<play>
|-------play.go
|-------mp3.go
|-------wav.go
|--------<music>
|-------mplayer.go
|------<pkg>
|------<bin>
------------------------------------------------------------------------------------
library：音乐库文件所在目录
[manager.go]
1 package library
2
3 import "errors"
4
5 type MusicEntry struct {
6 Id string
7 Name string
8 Artist string
9 Source string
10 Type string
11 }
12
13 type MusicManager struct {
14 musics []MusicEntry
15 }
16
17 func NewMusicManager() *MusicManager {
18 return &MusicManager{make([]MusicEntry, 0)}
19 }
20
21 func (m *MusicManager) Len() int {
22 return len(m.musics)
23 }
24
25 func (m *MusicManager) Get(index int) (music *MusicEntry, err error) {
26 if index <0 || index >= len(m.musics) {
27 return nil, errors.New("Index out of range.")
28 }
29 return &m.musics[index], nil
30 }
31
32 func (m *MusicManager) Find(name string) *MusicEntry {
33 if len(m.musics)==0 {
34 return nil
35 }
36
37 for _,mm := range m.musics {
38 if mm.Name == name {
39 return &mm
40 }
41 }
42 return nil
43 }
44
45 func (m *MusicManager)Add(music *MusicEntry) {
46 m.musics = append(m.musics, *music)
47 }
48
49 func (m *MusicManager)Remove(index int) *MusicEntry {
50 if index<0 || index >= len(m.musics) {
51 return nil
52 }
53
54 removedMusic := &m.musics[index]
55
56 if index < len(m.musics)-1 {
57 m.musics = append(m.musics[:index-1], m.musics[index+1:]...)
58 } else if index ==0 {
59 m.musics = make([]MusicEntry, 0)
60 }else {
61 m.musics = m.musics[:index-1]
62 }
63 return removedMusic
64 }
[manager_test.go]
1 package library
2
3 import (
4 "testing"
5 )
6
7 func TestOps(t *testing.T) {
8 mm := NewMusicManager()
9 if mm == nil {
10 t.Error("NewMusicManager() failed.")
11 }
12 m0 := &MusicEntry {"1", "Cellion Dion", "My Heart Will Go On", "http://qbox.me/24501234", "MP3" }
13 mm.Add(m0)
14
15 if mm.Len() != 1 {
16 t.Error("MusicManager.Add() failed.")
17 }
18
19 m := mm.Find(m0.Name)
20
21 if m == nil {
22 t.Error("MusicManager.Find() failed.")
23 }
24
25 if m.Id != m0.Id || m.Artist != m0.Artist || m.Name != m0.Name || m.Source != m0.Source || m.Type != m0.Type {
26 t.Error("MusicManager.Find() failed. Found item mismatch.")
27 }
28
29 m, err := mm.Get(0)
30
31 if m == nil {
32 t.Error("MusicManager.Get() failed.", err)
33 }
34
35 m = mm.Remove(0)
36 if m == nil || mm.Len() != 0 {
37 t.Error("MusicManager.Remove() failed.", err)
38 }
39 }
play：各种音乐类型存放库
[play.go]
1 package play
2
3 import "fmt"
4
5 type Player interface {
6 Play(source string)
7 }
8
9 func Play(source, mtype string) {
10 var p Player
11 switch mtype {
12 case "MP3":
13 p = &MP3Player{}
14 case "WAV":
15 p = &WAVPlayer{}
16 default:
17 fmt.Println("Unsupported music type", mtype)
18 return
19 }
20 p.Play(source)
21 }
[mp3.go]
1 package play
2
3 import (
4 "fmt"
5 "time"
6 )
7
8 type MP3Player struct {
9 stat int
10 progress int
11 }
12
13 func (p *MP3Player)Play(source string) {
14 fmt.Println("Playing MP3 music", source)
15
16 p.progress = 0
17
18 for p.progress < 100 {
19 time.Sleep(100*time.Millisecond)
20 fmt.Print(".")
21 p.progress += 1
22 }
23
24 fmt.Println("\nFinished playing", source)
25 }
[wav.go]
1 package play
2
3 import (
4 "fmt"
5 "time"
6 )
7
8 type WAVPlayer struct {
9 stat int
10 progress int
11 }
12
13 func (p *WAVPlayer) Play(source string) {
14 fmt.Println("Playing WAV music", source)
15
16 p.progress = 0
17
18 for p.progress < 100 {
19 time.Sleep(1000*time.Millisecond)
20 fmt.Print(".")
21 p.progress += 10
22 }
23
24 fmt.Println("\nFinished playing", source)
25 }
music：主程序的放在处
[mplayer.go]
1 package main
2
3 import (
4 "bufio"
5 "fmt"
6 "os"
7 "strconv"
8 "strings"
9 "play"
10 "library"
11 )
12
13 var lib *library.MusicManager
14 var id int = 1
15 var ctrl, signal chan int
16
17 func handleLibCommands(tokens []string) {
18 switch tokens[1] {
19 case "list" :
20 for i:=0; i<lib.Len(); i++ {
21 e,_ := lib.Get(i)
22 fmt.Println(i+1, ":", e.Name, e.Artist, e.Source, e.Type)
23 }
24 case "add":
25 if len(tokens) == 6 {
26 id++
27 lib.Add(&library.MusicEntry{string(strconv.Itoa(id)),tokens[2],tokens[3],tokens[4],tokens[5]})
28 }else {
29 fmt.Println("USAGE: library add <name><artist><source><type>")
30 }
31 case "remove":
32 if len(tokens) == 3 {
33 lib.Remove(3) // 有问题
34 } else {
35 fmt.Println("USAGE: library remove <name>")
36 }
37 default:
38 fmt.Println("Unrecongnized library command:", tokens[1])
39 }
40 }
41
42 func handlePlayCommands(tokens []string) {
43 if len(tokens) != 2 {
44 fmt.Println("USAGE: play <name>")
45 return
46 }
47
48 e := lib.Find(tokens[1])
49
50 if e == nil {
51 fmt.Println("The music", tokens[1], "does not exist.")
52 return
53 }
54
55 play.Play(e.Source, e.Type)
56 }
57
58 func main() {
59 fmt.Println(`
60 Enter following commands to control the player:
61 lib add <name><artist><source><type>
62 lib remove <name>
63 play <name>
64 `)
65
66 lib = library.NewMusicManager()
67
68 r := bufio.NewReader(os.Stdin)
69
70 for {
71 fmt.Println("Enter command->")
72
73 rawLine,_,_ := r.ReadLine()
74
75 line := string(rawLine)
76
77 if line == "q" || line == "e" {
78 break
79 }
80
81 tokens := strings.Split(line, " ")
82
83 if tokens[0] == "lib" {
84 handleLibCommands(tokens)
85 }else if tokens[0] == "play" {
86 handlePlayCommands(tokens)
87 }else {
88 fmt.Println("Unrecongnized command:", tokens[0])
89 }
90 }
91 }
；之后，返回到music目录节点，执行如下命令：
go build library
go build play
go build music
go test library
go install library
go install play
go install music
--------------------------------------------------------------------
接口使用的感受：
1、类似于C++中虚基类的作用，作为一个消费者的接口，用于接收生产者设计的方法；
2、生产者设计也简单，只需要实现接口中的方法就算设计了接口【无需如C++的，还需要继承】；
3、使用简单，设计也简单；
转载于:https://www.cnblogs.com/xuxu8511/p/3312063.html
标签：语言,musics,fmt,接口,tokens,go,GO,MusicManager,string 来源： https://blog.csdn.net/weixin_30652271/article/details/95731988