《go语言编程》音乐库代码
浏览数：48 /
时间：2015年06月10日
F:\golang
├─bin├─pkg
│
│
└─src
│ mplayer.go
│
└─mplayer
├─library
│ manager.go
│ manager_test.go
│
└─mp
mp3.go
play.go
GOPATH设为f:\golang
书中有一些错误的地方，改一下
myplay.go
======
package main
import (
"bufio"
"fmt"
"os"
"strconv"
"strings"
"mplayer/library"
"mplayer/mp"
)
var lib *library.MusicManager
var id int = 1
var ctrl, signal chan int
func handleLibCommands(tokens []string) {
if len(tokens) < 2 {
fmt.Println(`
Enter following commands to control the player:
lib list -- View the existing music lib
lib add <name><artist><source><type> -- Add a music to the music lib
lib remove <name> -- Remove the specified music from the lib
`)
return
}
switch tokens[1] {
case "list":
for i := 0; i < lib.Len(); i++ {
e, _ := lib.Get(i)
fmt.Println(i+1, ":", e.Name, e.Artist, e.Source, e.Type)
}
case "add":
{
if len(tokens) == 6 {
id++
lib.Add(&library.MusicEntry{strconv.Itoa(id),
tokens[2], tokens[3], tokens[4], tokens[5]})
} else {
fmt.Println("USAGE: lib add <name><artist><source><type>")
}
}
case "remove":
if len(tokens) == 3 {
index, _ := strconv.Atoi(tokens[2])
lib.Remove(index)
} else {
fmt.Println("USAGE: lib remove <name>")
}
default:
fmt.Println("Unrecognized lib command:", tokens[1])
}
}
func handlePlayCommand(tokens []string) {
if len(tokens) != 2 {
fmt.Println("USAGE: play <name>")
return
}
e := lib.Find(tokens[1])
if e == nil {
fmt.Println("The music", tokens[1], "does not exist.")
return
}
mp.Play(e.Source, e.Type)
}
func main() {
lib = library.NewMusicManager()
fmt.Println(`
Enter following commands to control the player:
lib list -- View the existing music lib
lib add <name><artist><source><type> -- Add a music to the music lib
lib remove <name> -- Remove the specified music from the lib
play <name> -- Play the specified music
q -- quit
`)
r := bufio.NewReader(os.Stdin)
for {
fmt.Print("Enter command-> ")
rawLine, _, _ := r.ReadLine()
line := string(rawLine)
if line == "q" || line == "e" {
break
}
tokens := strings.Split(line, " ")
if tokens[0] == "lib" {
handleLibCommands(tokens)
} else if tokens[0] == "play" {
handlePlayCommand(tokens)
} else {
fmt.Println("Unrecognized command:", tokens[0])
}
}
}
play.go
======
package mp
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 mp
import (
"fmt"
"time"
)
type MP3Player struct {
stat int
progress int
}
func (p *MP3Player) Play(source string) {
fmt.Println("Playing MP3 music", source)
p.progress = 0
for p.progress < 100 {
time.Sleep(100 * time.Millisecond) // 假装正在播放
fmt.Print(".")
p.progress += 10
}
fmt.Println("\nFinished playing", source)
}
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, 0)}
}
func (m *MusicManager) Len() int {
return len(m.musics)
}
func (m *MusicManager) Get(index int) (music *MusicEntry, err error) {
if index < 0 || 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) == 0 {
return nil
}
for _, m := range m.musics {
if m.Name == name {
return &m
}
}
return nil
}
func (m *MusicManager) Add(music *MusicEntry) {
m.musics = append(m.musics, *music)
}
func (m *MusicManager) Remove(index int) *MusicEntry {
if index < 0 || index >= len(m.musics) {
return nil
}
removedMusic := &m.musics[index]
// 从数组切片中删除元素
if index < len(m.musics)-1 { // 中间元素
m.musics = append(m.musics[:index-1], m.musics[index+1:]...)
} else if index == 0 { // 删除仅有的一个元素
m.musics = make([]MusicEntry, 0)
} else { // 删除的是最后一个元素
m.musics = m.musics[:index-1]
}
return removedMusic
}
manager_test.go
=============
package library
import (
"testing"
)
func TestOps(t *testing.T) {
mm := NewMusicManager()
if mm == nil {
t.Error("NewMusicManager failed.")
}
if mm.Len() != 0 {
t.Error("NewMusicManager failed, not empty.")
}
m0 := &MusicEntry{
"1", "My Heart Will Go On", "Celion Dion",
"http://qbox.me/24501234", "MP3"}
mm.Add(m0)
if mm.Len() != 1 {
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(0)
if m == nil {
t.Error("MusicManager.Get() failed.", err)
}
m = mm.Remove(0)
if m == nil || mm.Len() != 0 {
t.Error("MusicManager.Remove() failed.", err)
}
}
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