golang实现从服务器下载文件到本地指定目录

一、连接服务器，采用sftp连接模式

package middlewaresimport ("fmt""time""github.com/pkg/sftp""golang.org/x/crypto/ssh"
)// 建立服务器连接
func Connect(user, password, host string, port int) (*sftp.Client, error) {var (auth         []ssh.AuthMethodaddr         stringclientConfig *ssh.ClientConfigsshClient    *ssh.ClientsftpClient   *sftp.Clienterr          error)// get auth methodauth = make([]ssh.AuthMethod, 0)auth = append(auth, ssh.Password(password))clientConfig = &ssh.ClientConfig{User: user,Auth: []ssh.AuthMethod{ssh.Password(password)},// 此处忽略了密钥认证，改用密码认证HostKeyCallback: ssh.InsecureIgnoreHostKey(),Timeout:         30 * time.Second,}// 通过ssh连接到服务器addr = fmt.Sprintf("%s:%d", host, port)if sshClient, err = ssh.Dial("tcp", addr, clientConfig); err != nil {return nil, err}// 创建一个sftp连接工具用来读取文件或者目录if sftpClient, err = sftp.NewClient(sshClient); err != nil {return nil, err}return sftpClient, nil
}

二、下载文件

// 定义下载功能
func SyncCiticLog(r *gin.Context) {// viper设置的连接服务器的用户名和密码以及端口、连接的IP地址，此用户名写在了配置文件中User := viper.GetString("ConnectUser")Password := viper.GetString("ConnectPassword")Port := viper.GetInt("ConnectPort")citicIp := viper.GetString("ConnectOldIp")// 此处设置了要读取的目录前缀const allDir = "D:\\backup\\citic"// 定义变量用来接收下载文件的源目录和目标目录dstDir := ""srcDir := ""// 实例化结构体用来接收数据downloglist := DownLogList{}// 调用定义的sftp方法连接服务器sftpClient, sftpErr := middlewares.Connect(User, Password, citicIp, Port)// 此处要关闭要用defer关闭连接，否则下载的文件将发生打开文件错误defer sftpClient.Close()// 判断连接是否成功if sftpErr != nil {logs.Error(map[string]interface{}{"msg": sftpErr}, "未连接到服务器，请检查相关配置！")}// 此处用的Post请求，在请求体获取前端传递过来的参数if error := r.ShouldBindBodyWithJSON(&downloglist); error != nil {logs.Error(map[string]interface{}{"msg": "绑定结构体失败"}, "请检查配置文件是否正确！")} else {// 判断传递过来的IP，来定义相应的源目录和目标目录switch downloglist.ServiceIp {case "172.16.2.51":srcDir = "/home/backup/zqyl-abc/new"dstDir = "D:\\backup\\abc"breakcase "172.16.2.58":srcDir = "/home/backup/citic/" + downloglist.ServiceIpdstDir = filepath.Join(allDir, "中信03")breakcase "172.16.2.59":srcDir = "/home/backup/citic/" + downloglist.ServiceIpdstDir = filepath.Join(allDir, "中信04")breakcase "172.16.2.60":srcDir = "/home/backup/citic/" + downloglist.ServiceIpdstDir = filepath.Join(allDir, "中信01")breakcase "172.16.2.61":srcDir = "/home/backup/citic/" + downloglist.ServiceIpdstDir = filepath.Join(allDir, "中信02")break}// 由于传递过来的下载文件是多个，所以将以集合的形式传递过来，循环遍历来将单个文件进行下载for _, citicLog := range downloglist.LogList {// 拼出源文件的位置目录fileSrcDir := srcDir + "/" + citicLog// 利用sftp连接工具将文件目录打开openFile, err := sftpClient.Open(fileSrcDir)if err != nil {logs.Error(map[string]interface{}{"msg": "读取文件失败！"}, "请检查文件是否存在或者是否正常！")}// 创建本地文件存放的目录error := os.MkdirAll(dstDir, 0755)if error != nil {logs.Error(map[string]interface{}{"msg": "创建文件失败！"}, "请检查目录是否存在！")}// 创建本地文件的等待拷贝logFile, _ := os.Create(dstDir + "\\" + citicLog)// 创建资源记得关闭defer logFile.Close()// 拷贝文件至目标目录_, copyErr := io.Copy(logFile, openFile)if copyErr != nil {logs.Info(map[string]interface{}{"msg": "下载文件失败，请检查磁盘分区是否存在或者是否可写入状态！！"}, "")}}// 返回给前端状态码、下载成功信息、目标文件下载到的目录r.JSON(http.StatusOK, gin.H{"status":  http.StatusOK,"message": "下载成功！","path":    dstDir,})}
}