之前，已经讲过很多Golang的东西，比如基础语法，mysql的使用，redis的使用等等，感兴趣的可以看看以前的文章，https://www.cnblogs.com/zhangweizhong/category/1275863.html，

今天就用从头写一个完整的go的示例项目吧。

本项目完全使用原生开发，没有使用任何WEB框架和ORM。虽然大家对mvc 呀，三层架构已经很了解了。但是，我还是想从头写一个完整的示例项目。这样大家有一个更深刻的了解，这样以后介绍web框架，orm框架的时候，学习起来应该会简单一点。

项目架构

下图这种架构模式相信大家应该十分清楚

Controller组合封装

Controller"基类"封装

package frameworktype Controller struct {Data interface{}
}

UserController定义了用户注册，登录和查询等简单的三个接口

package controllerimport ("net/http""micro-cloud/service""micro-cloud/utils""micro-cloud/framework"
)/*** r.PostFormValue  : 可以解析 Post/PUT Content-Type=application/x-www-form-urlencoded 或 Content-Type=multipart/form-data*/type UserConterller struct {}var userService = new(service.UserService)func (p *UserConterller) Router(router *framework.RouterHandler) {router.Router("/register", p.register)router.Router("/login", p.login)router.Router("/findAll", p.findAll)
}//POST Content-Type=application/x-www-form-urlencoded
func (p *UserConterller) register(w http.ResponseWriter, r *http.Request) {username := r.PostFormValue("username")password := r.PostFormValue("password")if utils.Empty(username) || utils.Empty(password) {microcloud.ResultFail(w, "username or password can not be empty")return}id := userService.Insert(username, password)if id <= 0 {microcloud.ResultFail(w, "register fail")return}microcloud.ResultOk(w, "register success")
}//POST Content-Type=application/x-www-form-urlencoded
func (p *UserConterller) login(w http.ResponseWriter, r *http.Request) {username := r.PostFormValue("username")password := r.PostFormValue("password")if utils.Empty(username) || utils.Empty(password) {microcloud.ResultFail(w, "username or password can not be empty")return}users := userService.SelectUserByName(username)if len(users) == 0 {microcloud.ResultFail(w, "user does not exist")return}if users[0].Password != password {microcloud.ResultFail(w, "password error")return}microcloud.ResultOk(w, "login success")
}// GET/POST
func (p *UserConterller) findAll(w http.ResponseWriter, r *http.Request) {users := userService.SelectAllUser()framework.ResultJsonOk(w, users)
}

数据访问层

package daoimport ("micro-cloud/model""fmt")type UserDao struct {
}func (p *UserDao) Insert(user *model.User) int64 {result, err := framework.DB.Exec("INSERT INTO user(`username`,`password`,`create_time`) value(?,?,?)", user.Username, user.Password, user.CreateTime)if err != nil {fmt.Println("Insert error")return 0}id, err := result.LastInsertId()if err != nil {fmt.Println("Insert error")return 0}return id
}func (p *UserDao) SelectUserByName(username string) []model.User {rows, err := framework.DB.Query("SELECT * FROM user WHERE username = ?", username)if err != nil {fmt.Println("selectuserbyname error")return nil}var users []model.Userfor rows.Next() {var user model.Usererr := rows.Scan(&user.ID, &user.Username, &user.Password, &user.CreateTime)if err != nil {fmt.Println("selectuserbyname error")continue}users = append(users, user)}rows.Close()return users
}func (p *UserDao) SelectAllUser() []model.User {rows, err := framework.DB.Query("SELECT * FROM user")if err != nil {fmt.Println("SelectAllUser error")return nil}var users []model.Userfor rows.Next() {var user model.Usererr := rows.Scan(&user.ID, &user.Username, &user.Password, &user.CreateTime)if err != nil {fmt.Println("SelectAllUser error")continue}users = append(users, user)}rows.Close()return users
}

实体层

package modelimport "time"type User struct {ID         uint      `json:"id"`Username   string    `json:"username"`Password   string    `json:"-"`CreateTime time.Time `json:"create_time"`
}

database

数据库操作类的实现

package microcloudimport ("database/sql""log""strings"_ "github.com/go-sql-driver/mysql"
)//数据库的配置
const (username   = "admin"password   = "123456"ip         = "10.2.1.5"port       = "3306"dbName     = "microcloud"driverName = "mysql"
)//DB数据库连接池
var DB *sql.DBfunc InitDB() {//构建连接："用户名:密码@tcp(IP:端口)/数据库?charset=uft8"//注意：要想解析time.Time类型，必须要设置parseTime=Truepath := strings.Join([]string{username, ":", password, "@tcp(", ip, ":", port, ")/", dbName, "?charset=utf8&parseTime=True&loc=Local"}, "")//打开数据库，前者是驱动名，所以要导入:_"github.com/go-sql-driver/mysql"DB, _ = sql.Open(driverName, path)//设置数据库最大连接数DB.SetConnMaxLifetime(100)//设置数据库最大闲置连接数DB.SetMaxIdleConns(10)//验证连接if err := DB.Ping(); err != nil {log.Panic(err)}log.Println("database connect success")
}func CreateTable() {userTable := "CREATE TABLE IF NOT EXISTS `user`(" +"`id` INT UNSIGNED AUTO_INCREMENT," +"`username` VARCHAR(20) NOT NULL," +"`password` VARCHAR(40) NOT NULL," +"`create_time` DATETIME," +"PRIMARY KEY ( `id` )" +")ENGINE=InnoDB DEFAULT CHARSET=utf8;"_, err := DB.Exec(userTable)if err != nil {log.Panic(err)}
}

http

http server的实现

 server := &http.Server{Addr:        ":8215",Handler:     microcloud.Router,ReadTimeout: 5 * time.Second,}RegiterRouter(microcloud.Router)err := server.ListenAndServe()if err != nil {log.Panic(err)}

Router

路由处理的实现，其实也就是一个转发的功能

type RouterHandler struct {
}var mux = make(map[string]func(http.ResponseWriter,*http.Request))func (p *RouterHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {fmt.Println(r.URL.Path)if fun, ok := mux[r.URL.Path]; ok {fun(w, r)return}//静态资源if strings.HasPrefix(r.URL.Path,constant.STATIC_BAES_PATH){if fun, ok := mux[constant.STATIC_BAES_PATH]; ok {fun(w, r)return}}http.Error(w, "error URL:"+r.URL.String(), http.StatusBadRequest)}func (p *RouterHandler) Router(relativePath string, handler func(http.ResponseWriter, *http.Request)) {mux[rela

演示

执行 go run main.go 之后，打开Postman，调相关的接口

以下就是访问API的请求与响应

/findAll 接口

/register 接口

最后

以上，用Go语言实现webapi 的例子，已经介绍完了，虽然比较简单，session，权限验证等都没有加。但是最主要的功能已经讲完了，感兴趣的可以从头编写下相关的代码。

完整例子下载：microcloud.rar