gin框架路由传参与响应返回

1.路由传参

1.1 无参路由

请求地址：127.0.0.1:8000/hello

package main

import (
	"fmt"
	"github.com/gin-gonic/gin"
	"net/http"
)

func main() {
	r := gin.Default()
	r.GET("/hello", GetDemoHandler)
	r.Run(":8000")
}

func GetDemoHandler(c *gin.Context) {
	c.String(http.StatusOK, "hello,word")
}

执行结果

1.2. url参数路由（Query，DefaultQuery）

请求地址：127.0.0.1:8000/login?name=li&age=28

package main

import (
	"fmt"
	"github.com/gin-gonic/gin"
	"net/http"
)

func main() {
	r := gin.Default()
	r.GET("/login", GetLoginHandler)
	r.Run(":8000")
}


func GetLoginHandler(c *gin.Context) {
	//方式一:c.DefaultQuery获取值，如果没有使用默认值
	//127.0.0.1:8000/login?name=li&age=108
	/*
		name := c.DefaultQuery("name", "moren")
		age := c.DefaultQuery("age", "25")
		c.String(http.StatusOK, fmt.Sprintf("name=%v,age=%v",name, age)) //li 108
	*/
	//方式二:c.Query获取请求参数的值，没有默认值，如果没有为 nil
	name := c.Query("name")
	age := c.Query("age")
	c.String(http.StatusOK, fmt.Sprintf("name=%v,age=%v", name, age))
}

1.3. api参数路由（Param）

package main

import (
	"fmt"
	"github.com/gin-gonic/gin"
	"net/http"
)

func main() {
	r := gin.Default()
	r.GET("/book/:id", GetBookHandler) //使用 id来获取
	r.Run(":8000")
}

func GetBookHandler(c *gin.Context) {
	id := c.Param("id") //通过Context的Param方法来获取API参数,id需要跟路由中定义的id名一致
	c.String(http.StatusOK, fmt.Sprintf("第%v页", id))
}

1.4. 传值绑定到结构体（ShouldBind）

package main

import (
	"fmt"
	"github.com/gin-gonic/gin"
	"net/http"
)

func main() {
	r := gin.Default()
	r.POST("/user", GetUserHandler)
	r.Run(":8000")
}


type User struct {
	//binding:"required" 要求username字段不能为空
	Username string `from:"username" json:"username" binding:"required"`
	Password string `from:"password" json:"password" binding:"required"`
}

func GetUserHandler(c *gin.Context) {
	var User User              //定义一个结构体对象
	err := c.ShouldBind(&User) //必须要传入一个结构体对象
	if err != nil {
		c.String(http.StatusOK, fmt.Sprintln("err:", err)) //页面返回错误信息
	}
	c.String(http.StatusOK, fmt.Sprintf("username=%v,password=%v", User.Username, User.Password))
}

2. 响应和返回

2.1.响应字符串

package main

import (
	"github.com/gin-gonic/gin"
	"net/http"
)

func main() {
	r := gin.Default()
	r.GET("/string", GetStringHandler)
	r.Run(":8000")
}

func GetStringHandler(c *gin.Context) {
	c.String(http.StatusOK, "返回字符串")
}

2.2.响应json

package main

import (
	"github.com/gin-gonic/gin"
	"net/http"
)

func main() {
	r := gin.Default()
	r.GET("/json", GetJsonHandler)
	r.Run(":8000")
}

func GetJsonHandler(c *gin.Context) {
	/*
		//方式一:
		type Data struct {
			Msg  string `json:"msg"`
			Code int    `json:"code"`
		}
		d := Data{
			Msg:  "success",
			Code: 10011,
		}
		c.JSON(http.StatusOK, d)
	*/
	//方式二:
	c.JSON(http.StatusOK, gin.H{
		"Msg":  "success",
		"Code": 10011,
	})
}

2.3.路由重定向

package main

import (
	"github.com/gin-gonic/gin"
	"net/http"
)

func main() {
	r := gin.Default()
	r.GET("/redirect", GetRedirectHandler)
	r.Run(":8000")
}

func GetRedirectHandler(c *gin.Context) {
	//http.StatusMovedPermanently为状态码301
	//第二个参数为重定向之后的路径
	c.Redirect(http.StatusMovedPermanently, "https://www.baidu.com")
}