client.gogit
package main import ( "bufio" "encoding/json" "fmt" "hash/crc32" "math/rand" "net" "os" // "sync" "time" ) //數據包類型 const ( HEART_BEAT_PACKET = 0x00 REPORT_PACKET = 0x01 ) //默認的服務器地址 var ( server = "127.0.0.1:8080" ) //數據包 type Packet struct { PacketType byte PacketContent []byte } //心跳包 type HeartPacket struct { Version string `json:"version"` Timestamp int64 `json:"timestamp"` } //數據包 type ReportPacket struct { Content string `json:"content"` Rand int `json:"rand"` Timestamp int64 `json:"timestamp"` } //註冊 type RegisterReq struct { PERAESKey string `json:"PERAESKey"` VIN string `json:"VIN"` T_Box_SN string `json:"T_Box_SN"` IMSI string `json:"IMSI"` rollNumber string `json:"rollNumber"` } //客戶端對象 type TcpClient struct { connection *net.TCPConn hawkServer *net.TCPAddr stopChan chan struct{} } func main() { //拿到服務器地址信息 hawkServer, err := net.ResolveTCPAddr("tcp", server) if err != nil { fmt.Printf("hawk server [%s] resolve error: [%s]", server, err.Error()) os.Exit(1) } //鏈接服務器 connection, err := net.DialTCP("tcp", nil, hawkServer) if err != nil { fmt.Printf("connect to hawk server error: [%s]", err.Error()) os.Exit(1) } client := &TcpClient{ connection: connection, hawkServer: hawkServer, stopChan: make(chan struct{}), } //啓動接收 go client.receivePackets() //發送心跳的goroutine /*go func() { heartBeatTick := time.Tick(2 * time.Second) for { select { case <-heartBeatTick: client.sendHeartPacket() case <-client.stopChan: return } } }()*/ //測試用的，開300個goroutine每秒發送一個包 // for i := 0; i < 1; i++ { go func() { sendTimer := time.After(5 * time.Second) for { select { case <-sendTimer: client.sendReportPacket() sendTimer = time.After(1 * time.Second) case <-client.stopChan: return } } }() // } //等待退出 <-client.stopChan } // 接收數據包 func (client *TcpClient) receivePackets() { reader := bufio.NewReader(client.connection) for { //承接上面說的服務器端的偷懶，我這裏讀也只是以\n爲界限來讀區分包 msg, err := reader.ReadString('\n') if err != nil { //在這裏也請處理若是服務器關閉時的異常 close(client.stopChan) break } fmt.Print(msg) } } //發送數據包 //仔細看代碼其實這裏作了兩次json的序列化，有一次實際上是不須要的 func (client *TcpClient) sendReportPacket() { registPacket := RegisterReq{ PERAESKey: "123456", VIN: "abcdef", T_Box_SN: "abcdef123456", IMSI: "IMSI", rollNumber: getRandString(), /*Content: getRandString(), Timestamp: time.Now().Unix(), Rand: rand.Int(),*/ } fmt.Println("registPacket:", registPacket) packetBytes, err := json.Marshal(registPacket) //返回值是字節數組byte[], if err != nil { fmt.Println(err.Error()) } //這一次其實能夠不須要，在封包的地方把類型和數據傳進去便可 /*packet := Packet{ PacketType: REPORT_PACKET, PacketContent: packetBytes, } sendBytes, err := json.Marshal(packet) if err != nil { fmt.Println(err.Error()) }*/ //發送 client.connection.Write(EnPackSendData(packetBytes)) // fmt.Println("EnPackSendData(packetBytes):%v", EnPackSendData(packetBytes)) // fmt.Println("Send metric data success!") } //使用的協議與服務器端保持一致 func EnPackSendData(sendBytes []byte) []byte { packetLength := len(sendBytes) + 8 result := make([]byte, packetLength) result[0] = 0xFF result[1] = 0xFF result[2] = byte(uint16(len(sendBytes)) >> 8) //除以2的8次方,byte是0-255， result[3] = byte(uint16(len(sendBytes)) & 0xFF) copy(result[4:], sendBytes) sendCrc := crc32.ChecksumIEEE(sendBytes) result[packetLength-4] = byte(sendCrc >> 24) result[packetLength-3] = byte(sendCrc >> 16 & 0xFF) result[packetLength-2] = 0xFF result[packetLength-1] = 0xFE fmt.Println(result) return result } //發送心跳包，與發送數據包同樣 func (client *TcpClient) sendHeartPacket() { heartPacket := HeartPacket{ Version: "1.0", Timestamp: time.Now().Unix(), } packetBytes, err := json.Marshal(heartPacket) if err != nil { fmt.Println(err.Error()) } packet := Packet{ PacketType: HEART_BEAT_PACKET, PacketContent: packetBytes, } sendBytes, err := json.Marshal(packet) if err != nil { fmt.Println(err.Error()) } client.connection.Write(EnPackSendData(sendBytes)) fmt.Println("Send heartbeat data success!") } //拿一串隨機字符 func getRandString() string { // length := rand.Intn(10) strBytes := make([]byte, 10) for i := 0; i < 10; i++ { strBytes[i] = byte(rand.Intn(26) + 97) } return string(strBytes) } /*做者：getyouyou 連接：https://www.jianshu.com/p/dbc62a879081 來源：簡書 著做權歸做者全部。商業轉載請聯繫做者得到受權，非商業轉載請註明出處。*/
server.gogithub
package main import ( "bufio" "encoding/json" "fmt" "hash/crc32" "io" "net" "os" ) //數據包的類型 const ( HEART_BEAT_PACKET = 0x00 REPORT_PACKET = 0x01 ) var ( server = "127.0.0.1:8080" ) //這裏是包的結構體，實際上是能夠不須要的 type Packet struct { PacketType byte PacketContent []byte } //註冊 type RegisterReq struct { PERAESKey string `json:"PERAESKey"` VIN string `json:"VIN"` T_Box_SN string `json:"T_Box_SN"` IMSI string `json:"IMSI"` rollNumber string `json:"rollNumber"` } //心跳包，這裏用了json來序列化，也能夠用github上的gogo/protobuf包 //具體見(https://github.com/gogo/protobuf) type HeartPacket struct { Version string `json:"version"` Timestamp int64 `json:"timestamp"` } //正式上傳的數據包 type ReportPacket struct { Content string `json:"content"` Rand int `json:"rand"` Timestamp int64 `json:"timestamp"` } //與服務器相關的資源都放在這裏面 type TcpServer struct { listener *net.TCPListener hawkServer *net.TCPAddr } func main() { //相似於初始化套接字，綁定端口 hawkServer, err := net.ResolveTCPAddr("tcp", server) checkErr(err) //偵聽 listen, err := net.ListenTCP("tcp", hawkServer) checkErr(err) //記得關閉 defer listen.Close() tcpServer := &TcpServer{ listener: listen, hawkServer: hawkServer, } fmt.Println("start server successful......") //開始接收請求 for { conn, err := tcpServer.listener.Accept() fmt.Println("accept tcp client %s", conn.RemoteAddr().String()) checkErr(err) // 每次創建一個鏈接就放到單獨的協程內作處理 go Handle(conn) } } //處理函數，這是一個狀態機 //根據數據包來作解析 //數據包的格式爲|0xFF|0xFF|len(高)|len(低)|Data|CRC高16位|0xFF|0xFE //其中len爲data的長度，實際長度爲len(高)*256+len(低) //CRC爲32位CRC，取了最高16位共2Bytes //0xFF|0xFF和0xFF|0xFE相似於前導碼 func Handle(conn net.Conn) { // close connection before exit defer conn.Close() // 狀態機狀態 state := 0x00 // 數據包長度 length := uint16(0) // crc校驗和 crc16 := uint16(0) var recvBuffer []byte // 遊標 cursor := uint16(0) bufferReader := bufio.NewReader(conn) //狀態機處理數據 for { recvByte, err := bufferReader.ReadByte() //recvByte是每次讀到的字節 if err != nil { //這裏由於作了心跳，因此就沒有加deadline時間，若是客戶端斷開鏈接 //這裏ReadByte方法返回一個io.EOF的錯誤，具體可考慮文檔 /*Handle方法在一個死循環中使用了一個無阻塞的buff來讀取套接字中的數據， 所以當客戶端主動關閉鏈接時，若是不對這個io.EOF進行處理，會致使這個goroutine空轉， 瘋狂吃cpu，在這裏io.EOF的處理很是重要:)*/ if err == io.EOF { fmt.Printf("client %s is close!\n", conn.RemoteAddr().String()) } //在這裏直接退出goroutine，關閉由defer操做完成 return } //進入狀態機，根據不一樣的狀態來處理 switch state { case 0x00: if recvByte == 0xFF { state = 0x01 //初始化狀態機 recvBuffer = nil length = 0 crc16 = 0 } else { state = 0x00 } break case 0x01: if recvByte == 0xFF { state = 0x02 } else { state = 0x00 } break case 0x02: length += uint16(recvByte) * 256 //length此次是發送數據的長度 fmt.Println("0x02,length:%d", length) //0 state = 0x03 break case 0x03: length += uint16(recvByte) fmt.Println("0x03,length:%d", length) //77 // 一次申請緩存，初始化遊標，準備讀數據 recvBuffer = make([]byte, length) cursor = 0 state = 0x04 break case 0x04: //不斷地在這個狀態下讀數據，直到知足長度爲止 recvBuffer[cursor] = recvByte cursor++ if cursor == length { state = 0x05 } break case 0x05: crc16 += uint16(recvByte) * 256 //crc32編碼 state = 0x06 break case 0x06: crc16 += uint16(recvByte) state = 0x07 break case 0x07: if recvByte == 0xFF { state = 0x08 } else { state = 0x00 } case 0x08: if recvByte == 0xFE { //執行數據包校驗 if (crc32.ChecksumIEEE(recvBuffer)>>16)&0xFFFF == uint32(crc16) { var packet RegisterReq //把拿到的數據反序列化出來 json.Unmarshal(recvBuffer, &packet) //新開協程處理數據 go processRecvData(&packet, conn) } else { fmt.Println("丟棄數據!") } } //狀態機歸位,接收下一個包 state = 0x00 } } } //在這裏處理收到的包，就和通常的邏輯同樣了，根據類型進行不一樣的處理，因人而異 //我這裏處理了心跳和一個上報數據包 //服務器往客戶端的數據包很簡單地以\n換行結束了，偷了一個懶:)，正常狀況下也可根據本身的協議來封裝好 //而後在客戶端寫一個狀態來處理 func processRecvData(packet *RegisterReq, conn net.Conn) { // switch packet.PacketType { // case HEART_BEAT_PACKET: // var beatPacket HeartPacket // json.Unmarshal(packet.PacketContent, &beatPacket) fmt.Printf("recieve heat beat from [%s] ,data is [%v]\n", conn.RemoteAddr().String(), packet) conn.Write([]byte("heartBeat\n")) return // case REPORT_PACKET: // var reportPacket ReportPacket // json.Unmarshal(packet.PacketContent, &reportPacket) // fmt.Printf("recieve report data from [%s] ,data is [%v]\n", conn.RemoteAddr().String(), reportPacket) // conn.Write([]byte("Report data has recive\n")) // return // } } //處理錯誤，根據實際狀況選擇這樣處理，仍是在函數調以後不一樣的地方不一樣處理 func checkErr(err error) { if err != nil { fmt.Println(err) os.Exit(-1) } } /*做者：getyouyou 連接：https://www.jianshu.com/p/dbc62a879081 來源：簡書 著做權歸做者全部。商業轉載請聯繫做者得到受權，非商業轉載請註明出處。*/