Golang Web开发
HTTP基础
简单的HTTP服务器
go
package main
import (
"fmt"
"net/http"
)
func helloHandler(w http.ResponseWriter, r *http.Request) {
fmt.Fprintf(w, "Hello, World!")
}
func main() {
http.HandleFunc("/", helloHandler)
fmt.Println("Server starting on port 8080...")
http.ListenAndServe(":8080", nil)
}路由处理
go
package main
import (
"fmt"
"net/http"
)
func homeHandler(w http.ResponseWriter, r *http.Request) {
fmt.Fprintf(w, "<h1>Welcome to Home Page</h1>")
}
func aboutHandler(w http.ResponseWriter, r *http.Request) {
fmt.Fprintf(w, "<h1>About Us</h1>")
}
func userHandler(w http.ResponseWriter, r *http.Request) {
name := r.URL.Path[len("/user/"):]
fmt.Fprintf(w, "<h1>Hello, %s!</h1>", name)
}
func main() {
http.HandleFunc("/", homeHandler)
http.HandleFunc("/about", aboutHandler)
http.HandleFunc("/user/", userHandler)
fmt.Println("Server starting on port 8080...")
http.ListenAndServe(":8080", nil)
}使用Gin框架
安装Gin
bash
go get -u github.com/gin-gonic/gin基本使用
go
package main
import (
"net/http"
"github.com/gin-gonic/gin"
)
func main() {
r := gin.Default()
r.GET("/", func(c *gin.Context) {
c.JSON(200, gin.H{
"message": "Hello, Gin!",
})
})
r.GET("/user/:name", func(c *gin.Context) {
name := c.Param("name")
c.JSON(200, gin.H{
"message": "Hello " + name,
})
})
r.GET("/welcome", func(c *gin.Context) {
firstname := c.DefaultQuery("firstname", "Guest")
lastname := c.Query("lastname")
c.String(http.StatusOK, "Hello %s %s", firstname, lastname)
})
r.Run(":8080")
}POST请求处理
go
type LoginForm struct {
User string `form:"username" binding:"required"`
Password string `form:"password" binding:"required"`
}
func main() {
r := gin.Default()
r.POST("/login", func(c *gin.Context) {
var form LoginForm
if err := c.ShouldBind(&form); err != nil {
c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
return
}
if form.User == "admin" && form.Password == "password" {
c.JSON(http.StatusOK, gin.H{"status": "logged in"})
} else {
c.JSON(http.StatusUnauthorized, gin.H{"status": "unauthorized"})
}
})
r.Run(":8080")
}JSON数据处理
go
type User struct {
Name string `json:"name"`
Email string `json:"email"`
Age int `json:"age"`
}
func main() {
r := gin.Default()
r.POST("/user", func(c *gin.Context) {
var user User
if err := c.ShouldBindJSON(&user); err != nil {
c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
return
}
c.JSON(http.StatusOK, gin.H{
"message": "User created",
"user": user,
})
})
r.Run(":8080")
}路由组
go
func main() {
r := gin.Default()
// API路由组
api := r.Group("/api/v1")
{
api.GET("/users", getUsers)
api.GET("/users/:id", getUser)
api.POST("/users", createUser)
api.PUT("/users/:id", updateUser)
api.DELETE("/users/:id", deleteUser)
}
r.Run(":8080")
}
func getUsers(c *gin.Context) {
c.JSON(200, gin.H{"users": "list of users"})
}
func getUser(c *gin.Context) {
id := c.Param("id")
c.JSON(200, gin.H{"user": "user " + id})
}
func createUser(c *gin.Context) {
c.JSON(201, gin.H{"message": "user created"})
}
func updateUser(c *gin.Context) {
id := c.Param("id")
c.JSON(200, gin.H{"message": "user " + id + " updated"})
}
func deleteUser(c *gin.Context) {
id := c.Param("id")
c.JSON(200, gin.H{"message": "user " + id + " deleted"})
}中间件
自定义中间件
go
func Logger() gin.HandlerFunc {
return func(c *gin.Context) {
t := time.Now()
// 设置变量
c.Set("example", "12345")
// 请求前
c.Next()
// 请求后
latency := time.Since(t)
log.Print(latency)
// 访问状态
status := c.Writer.Status()
log.Println(status)
}
}
func main() {
r := gin.New()
r.Use(Logger())
r.GET("/test", func(c *gin.Context) {
example := c.MustGet("example").(string)
log.Println(example)
})
r.Run(":8080")
}认证中间件
go
func AuthRequired() gin.HandlerFunc {
return func(c *gin.Context) {
token := c.GetHeader("Authorization")
if token == "" {
c.JSON(http.StatusUnauthorized, gin.H{"error": "Authorization required"})
c.Abort()
return
}
// 验证token逻辑
if token != "valid-token" {
c.JSON(http.StatusUnauthorized, gin.H{"error": "Invalid token"})
c.Abort()
return
}
c.Next()
}
}
func main() {
r := gin.Default()
// 公开路由
r.GET("/", func(c *gin.Context) {
c.JSON(200, gin.H{"message": "public"})
})
// 需要认证的路由
authorized := r.Group("/admin")
authorized.Use(AuthRequired())
{
authorized.GET("/dashboard", func(c *gin.Context) {
c.JSON(200, gin.H{"message": "admin dashboard"})
})
}
r.Run(":8080")
}静态文件服务
go
func main() {
r := gin.Default()
// 单个文件
r.StaticFile("/favicon.ico", "./resources/favicon.ico")
// 整个目录
r.Static("/static", "./static")
// 使用前缀
r.StaticFS("/more_static", http.Dir("my_file_system"))
r.Run(":8080")
}模板渲染
HTML模板
go
func main() {
router := gin.Default()
router.LoadHTMLGlob("templates/*")
router.GET("/index", func(c *gin.Context) {
c.HTML(http.StatusOK, "index.tmpl", gin.H{
"title": "Main website",
})
})
router.Run(":8080")
}模板文件示例 (templates/index.tmpl)
html
<!DOCTYPE html>
<html>
<head>
<title>{{ .title }}</title>
</head>
<body>
<h1>{{ .title }}</h1>
</body>
</html>错误处理
go
func main() {
r := gin.Default()
r.Use(gin.CustomRecovery(func(c *gin.Context, recovered interface{}) {
if err, ok := recovered.(string); ok {
c.String(http.StatusInternalServerError, fmt.Sprintf("error: %s", err))
}
c.AbortWithStatus(http.StatusInternalServerError)
}))
r.GET("/panic", func(c *gin.Context) {
panic("foo")
})
r.Run(":8080")
}