map按插入顺序排序后生成json

发表于： 2023年4月3日 2023年4月3日
分类： Go

类似java中的LinkedHashMap，输出的json串是按key的插入顺序排序的

场景
一个java项目，重构为go 某一个接口返回的数据结构是和客户端约定好的，有排序规则；返回结果是按key插入顺序进行排序的一个map转成的字符串（java中可以直接用LinkedHashMap，然后转json）

package main

import (
    "fmt"
    "strings"
    "encoding/json"
)

type Smap []*SortMapNode

type SortMapNode struct {
    Key string
    Val interface{}
}

func (c *Smap) Put(key string, val interface{}) {
    index, _, ok := c.get(key)
    if ok {
        (*c)[index].Val = val
    } else {
        node := &SortMapNode{Key: key, Val: val}
        *c = append(*c, node)
    }
}

func (c *Smap) Get(key string) (interface{}, bool) {
    _, val, ok := c.get(key)
    return val, ok
}

func (c *Smap) get(key string) (int, interface{}, bool) {
    for index, node := range *c {
        if node.Key == key {
            return index, node.Val, true
        }
    }
    return -1, nil, false
}

func ToSortedMapJson(smap *Smap) string {
    s := "{"
    for _, node := range *smap {
        v := node.Val
        isSamp := false
        str := ""
        switch v.(type){
            case *Smap:
                isSamp = true
                str = ToSortedMapJson(v.(*Smap))
        }

        if(!isSamp){
            b, _ := json.Marshal(node.Val)
            str = string(b)
        }

        s = fmt.Sprintf("%s\"%s\":%s,", s, node.Key, str)
    }
    s = strings.TrimRight(s, ",")
    s = fmt.Sprintf("%s}", s)
    return s
}

type testStruct struct{
    name string
    value interface{} 
}

func main(){
    smap := &Smap{}

    n1 := []int{5, 6}
    n2 := []string{"s3", "s4"}
    n3 := []string{"s1", "s2"}
    n4 := []interface{}{"a",5,6.7}
    n4 = append(n4, "t")
    n4 = append(n4, 1)
    n4 = append(n4, 3.2)

    s1 := &Smap{}
    s1.Put("first", "1str")
    s1.Put("second", "2str")
    s1.Put("third", "3str")

    s2 := &Smap{}
    var t2 testStruct
    t2.name = "testname"
    t2.value = s2
    s2.Put("s1", s1)

    arr2 := []string{"str1", "str2"}
    s2.Put("arr2", arr2)

    smap.Put("1int", n1)
    smap.Put("2string", n2)
    smap.Put("3string", n3)
    smap.Put("4interface", n4)
    smap.Put("5smap", s1)
    smap.Put("6interfaceSmap", s2)

    s := ToSortedMapJson(smap)
    fmt.Println(s)
}

example

smap := &Smap{}
smap.Put("name", "myname")
smap.Put("attr", "123")
s := ToSortedMapJson(smap)
fmt.Println(s)

结果输出

{
    "1int": [5, 6],
    "2string": ["s3", "s4"],
    "3string": ["s1", "s2"],
    "4interface": ["a", 5, 6.7, "t", 1, 3.2],
    "5smap": {
        "first": "1str",
        "second": "2str",
        "third": "3str"
    },
    "6interfaceSmap": {
        "s1": {
            "first": "1str",
            "second": "2str",
            "third": "3str"
        },
        "arr2": ["str1", "str2"]
    }
}

admin

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