<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]
package library
import "errors"
type MusicEntry struct {
Id string
Name string
Artist string
Source string
Type string
}
type MusicManager struct {
musics []MusicEntry
}
func NewMusicManager() *MusicManager {
return &MusicManager{make([]MusicEntry, )}
}
func (m *MusicManager) Len() int {
return len(m.musics)
}
func (m *MusicManager) Get(index int) (music *MusicEntry, err error) {
if index < || index >= len(m.musics) {
return nil, errors.New("Index out of range.")
}
return &m.musics[index], nil
}
func (m *MusicManager) Find(name string) *MusicEntry {
if len(m.musics)== {
return nil
}
for _,mm := range m.musics {
if mm.Name == name {
return &mm
}
}
return nil
}
func (m *MusicManager)Add(music *MusicEntry) {
m.musics = append(m.musics, *music)
}
func (m *MusicManager)Remove(index int) *MusicEntry {
if index< || index >= len(m.musics) {
return nil
}
removedMusic := &m.musics[index]
if index < len(m.musics)- {
m.musics = append(m.musics[:index-], m.musics[index+:]...)
} else if index == {
m.musics = make([]MusicEntry, )
}else {
m.musics = m.musics[:index-]
}
return removedMusic
}
[manager_test.go]
package library import (
"testing"
) func TestOps(t *testing.T) {
mm := NewMusicManager()
if mm == nil {
t.Error("NewMusicManager() failed.")
}
m0 := &MusicEntry {"", "Cellion Dion", "My Heart Will Go On", "http://qbox.me/24501234", "MP3" }
mm.Add(m0) if mm.Len() != {
t.Error("MusicManager.Add() failed.")
} m := mm.Find(m0.Name) if m == nil {
t.Error("MusicManager.Find() failed.")
} if m.Id != m0.Id || m.Artist != m0.Artist || m.Name != m0.Name || m.Source != m0.Source || m.Type != m0.Type {
t.Error("MusicManager.Find() failed. Found item mismatch.")
} m, err := mm.Get() if m == nil {
t.Error("MusicManager.Get() failed.", err)
} m = mm.Remove()
if m == nil || mm.Len() != {
t.Error("MusicManager.Remove() failed.", err)
}
}
play：各种音乐类型存放库
[play.go]
package play
import "fmt"
type Player interface {
Play(source string)
}
func Play(source, mtype string) {
var p Player
switch mtype {
case "MP3":
p = &MP3Player{}
case "WAV":
p = &WAVPlayer{}
default:
fmt.Println("Unsupported music type", mtype)
return
}
p.Play(source)
}
[mp3.go]
package play import (
"fmt"
"time"
) type MP3Player struct {
stat int
progress int
} func (p *MP3Player)Play(source string) {
fmt.Println("Playing MP3 music", source) p.progress = for p.progress < {
time.Sleep(*time.Millisecond)
fmt.Print(".")
p.progress +=
} fmt.Println("\nFinished playing", source)
}
[wav.go]
package play import (
"fmt"
"time"
) type WAVPlayer struct {
stat int
progress int
} func (p *WAVPlayer) Play(source string) {
fmt.Println("Playing WAV music", source) p.progress = for p.progress < {
time.Sleep(*time.Millisecond)
fmt.Print(".")
p.progress +=
} fmt.Println("\nFinished playing", source)
}
music：主程序的放在处
[mplayer.go]
package main import (
"bufio"
"fmt"
"os"
"strconv"
"strings"
"play"
"library"
) var lib *library.MusicManager
var id int =
var ctrl, signal chan int func handleLibCommands(tokens []string) {
switch tokens[] {
case "list" :
for i:=; i<lib.Len(); i++ {
e,_ := lib.Get(i)
fmt.Println(i+, ":", e.Name, e.Artist, e.Source, e.Type)
}
case "add":
if len(tokens) == {
id++
lib.Add(&library.MusicEntry{string(strconv.Itoa(id)),tokens[],tokens[],tokens[],tokens[]})
}else {
fmt.Println("USAGE: library add <name><artist><source><type>")
}
case "remove":
if len(tokens) == {
lib.Remove() // 有问题
} else {
fmt.Println("USAGE: library remove <name>")
}
default:
fmt.Println("Unrecongnized library command:", tokens[])
}
} func handlePlayCommands(tokens []string) {
if len(tokens) != {
fmt.Println("USAGE: play <name>")
return
} e := lib.Find(tokens[]) if e == nil {
fmt.Println("The music", tokens[], "does not exist.")
return
} play.Play(e.Source, e.Type)
} func main() {
fmt.Println(`
Enter following commands to control the player:
lib add <name><artist><source><type>
lib remove <name>
play <name>
`) lib = library.NewMusicManager() r := bufio.NewReader(os.Stdin) for {
fmt.Println("Enter command->") rawLine,_,_ := r.ReadLine() line := string(rawLine) if line == "q" || line == "e" {
break
} tokens := strings.Split(line, " ") if tokens[] == "lib" {
handleLibCommands(tokens)
}else if tokens[] == "play" {
handlePlayCommands(tokens)
}else {
fmt.Println("Unrecongnized command:", tokens[])
}
}
}
；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；