简介
Gin是一个golang的微框架，封装比较优雅，API友好，源码注释比较明确，具有快速灵活，容错方便等特点
对于golang而言，web框架的依赖要远比Python，Java之类的要小。自身的net/http足够简单，性能也非常不错
借助框架开发，不仅可以省去很多常用的封装带来的时间，也有助于团队的编码风格和形成规范
package main
import (
"github.com/gin-gonic/gin"
"net/http"
)
func main() {
r := gin.Default() //初始化
r.GET("/", func(c *gin.Context) {
c.String(http.StatusOK, "hello world")
}) //get请求
r.Run(":8080") //在8080端口启动监听
}
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获取param参数
package main
import (
"github.com/gin-gonic/gin"
"net/http"
"strings"
)
func main() {
r := gin.Default()
r.GET("/user/:name/*action", func(c *gin.Context) {
name := c.Param("name")
action := c.Param("action")
action = strings.Trim(action, "/")
c.String(http.StatusOK, name+" is "+action)
})
r.Run(":8000")
}
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获取Query参数
package main
import (
"fmt"
"net/http"
"github.com/gin-gonic/gin"
)
func main() {
r := gin.Default()
r.GET("/user", func(c *gin.Context) {
//指定默认值
//http://localhost:8080/user 才会打印出来默认的值
name := c.DefaultQuery("name", "jerry")
c.String(http.StatusOK, fmt.Sprintf("hello %s", name))
})
r.Run(":8000")
}
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获取表单参数
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<body>
<form action="http://localhost:8080/form" method="post" action="application/x-www-form-urlencoded">
用户名：<input type="text" name="username" placeholder="请输入你的用户名"> <br>
密 码：<input type="password" name="userpassword" placeholder="请输入你的密码"> <br>
<input type="submit" value="提交">
</form>
</body>
</html>
package main
//
import (
"fmt"
"net/http"
"github.com/gin-gonic/gin"
)
func main() {
r := gin.Default()
r.POST("/form", func(c *gin.Context) {
types := c.DefaultPostForm("type", "post")
username := c.PostForm("username")
password := c.PostForm("userpassword")
// c.String(http.StatusOK, fmt.Sprintf("username:%s,password:%s,type:%s", username, password, types))
c.String(http.StatusOK, fmt.Sprintf("username:%s,password:%s,type:%s", username, password, types))
})
r.Run()
}
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上传单个文件
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<body>
<form action="http://localhost:8080/upload" method="post" enctype="multipart/form-data">
上传文件:<input type="file" name="file" >
<input type="submit" value="提交">
</form>
</body>
</html>
package main
import (
"github.com/gin-gonic/gin"
)
func main() {
r := gin.Default()
//限制上传最大尺寸
r.MaxMultipartMemory = 8 << 20
r.POST("/upload", func(c *gin.Context) {
file, err := c.FormFile("file")
if err != nil {
c.String(500, "上传图片出错")
}
// c.JSON(200, gin.H{"message": file.Header.Context})
c.SaveUploadedFile(file, file.Filename)
c.String(http.StatusOK, file.Filename)
})
r.Run()
}
上传多个文件
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<body>
<form action="http://localhost:8000/upload" method="post" enctype="multipart/form-data">
上传文件:<input type="file" name="files" multiple>
<input type="submit" value="提交">
</form>
</body>
</html>
package main
import (
"github.com/gin-gonic/gin"
"net/http"
"fmt"
)
func main() {
// 1.创建路由
// 默认使用了2个中间件Logger(), Recovery()
r := gin.Default()
// 限制表单上传大小 8MB，默认为32MB
r.MaxMultipartMemory = 8 << 20
r.POST("/upload", func(c *gin.Context) {
form, err := c.MultipartForm()
if err != nil {
c.String(http.StatusBadRequest, fmt.Sprintf("get err %s", err.Error()))
}
// 获取所有图片
files := form.File["files"]
// 遍历所有图片
for _, file := range files {
// 逐个存
if err := c.SaveUploadedFile(file, file.Filename); err != nil {
c.String(http.StatusBadRequest, fmt.Sprintf("upload err %s", err.Error()))
return
}
}
c.String(200, fmt.Sprintf("upload ok %d files", len(files)))
})
//默认端口号是8080
r.Run(":8000")
}
路由分组
package main
import (
"github.com/gin-gonic/gin"
"fmt"
)
// gin的helloWorld
func main() {
// 1.创建路由
// 默认使用了2个中间件Logger(), Recovery()
r := gin.Default()
// 路由组1 ，处理GET请求
v1 := r.Group("/v1")
// {} 是书写规范
{
v1.GET("/login", login)
v1.GET("submit", submit)
}
v2 := r.Group("/v2")
{
v2.POST("/login", login)
v2.POST("/submit", submit)
}
r.Run(":8000")
}
func login(c *gin.Context) {
name := c.DefaultQuery("name", "jack")
c.String(200, fmt.Sprintf("hello %s\n", name))
}
func submit(c *gin.Context) {
name := c.DefaultQuery("name", "lily")
c.String(200, fmt.Sprintf("hello %s\n", name))
}
重定向
package main
import (
"net/http"
"github.com/gin-gonic/gin"
)
func main() {
r := gin.Default()
r.GET("/index", func(c *gin.Context) {
c.Redirect(http.StatusMovedPermanently, "http://www.5lmh.com")
})
r.Run()
}
中间件
全局中间件
package main
import (
"fmt"
"time"
"github.com/gin-gonic/gin"
)
// 定义中间
func MiddleWare() gin.HandlerFunc {
return func(c *gin.Context) {
t := time.Now()
fmt.Println("中间件开始执行了")
// 设置变量到Context的key中，可以通过Get()取
c.Set("request", "中间件")
status := c.Writer.Status()
fmt.Println("中间件执行完毕", status)
t2 := time.Since(t)
fmt.Println("time:", t2)
}
}
func main() {
// 1.创建路由
// 默认使用了2个中间件Logger(), Recovery()
r := gin.Default()
// 注册中间件
r.Use(MiddleWare())
// {}为了代码规范
{
r.GET("/ce", func(c *gin.Context) {
// 取值
req, _ := c.Get("request")
fmt.Println("request:", req)
// 页面接收
c.JSON(200, gin.H{"request": req})
})
}
r.Run()
}
局部中间件
package main
import (
"fmt"
"time"
"github.com/gin-gonic/gin"
)
// 定义中间
func MiddleWare() gin.HandlerFunc {
return func(c *gin.Context) {
t := time.Now()
fmt.Println("中间件开始执行了")
// 设置变量到Context的key中，可以通过Get()取
c.Set("request", "中间件")
// 执行函数
c.Next()
// 中间件执行完后续的一些事情
status := c.Writer.Status()
fmt.Println("中间件执行完毕", status)
t2 := time.Since(t)
fmt.Println("time:", t2)
}
}
func main() {
// 1.创建路由
// 默认使用了2个中间件Logger(), Recovery()
r := gin.Default()
//局部中间键使用
r.GET("/ce", MiddleWare(), func(c *gin.Context) {
// 取值
req, _ := c.Get("request")
fmt.Println("request:", req)
// 页面接收
c.JSON(200, gin.H{"request": req})
})
r.Run()
}
中间件练习-登录校验
package main
import (
"fmt"
"github.com/gin-gonic/gin"
"net/http"
)
func middleWare() gin.HandlerFunc {
return func(c *gin.Context) {
name := c.Param("username")
password := c.Param("password")
fmt.Println(name)
fmt.Println(password)
if name == "admin" && password == "123" {
c.Next()
} else {
c.String(http.StatusBadRequest, "登录失败")
c.Abort()
}
}
}
func main() {
r := gin.Default()
r.GET("/login/:username/:password", middleWare(), func(c *gin.Context) {
c.String(http.StatusOK, "loginSuccessfully")
})
r.Run(":8000")
}
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