go-json数据处理

这里以插入更新ES返回的json数据为例：

{
"_index":"zhenai",
"_type":"users",
"_id":"0",
"_version":28,
"result":"updated",
"forced_refresh":true,
"_shards":{"total":2,"successful":1,"failed":0},
"_seq_no":172,
"_primary_term":1
}

json数据处理方法一

• 我们可以直接将json数据映射到预定义好的结构体中，但是必须要确保json的字段和结构体必须要一致。

json数据处理方式二

• 如果JSON数据的定义过于复杂化，可以将JSON数据映射到一个map中，这样处理更加灵活。

以下为ES操作的一个简单code 包含了两种处理方式

package persist

import (
    "bufio"
    "context"
    "encoding/json"
    "fmt"
    "github.com/elastic/go-elasticsearch/v7"
    "github.com/elastic/go-elasticsearch/v7/esapi"
    "io/ioutil"
    "learn16/model"
    "reflect"
    "strconv"
    "strings"
)

type shard struct {
    Total int `json:"total"`
    Successful int `json:"successful"`
    Failed int `json:"failed"`
}

type result struct {
    Index string `json:"_index"`
    Type string `json:"_type"`
    Id string `json:"_id"`
    Version int `json:"_version"`
    Result string `json:"result"`
    ForcedRefresh bool `json:"forced_refresh"`
    Shards shard `json:"_shards"`
    SeqNo int `json:"_seq_no"`
    PrimaryTerm int `json:"_primary_term"`
}

func save(i int, item interface{}) (id string, err error) {
    //type assertion
    user := item.(model.User)
    client, err := elasticsearch.NewDefaultClient()
    if err != nil {
        return "", err
    }
    //build the request body
    var b strings.Builder
    t := reflect.TypeOf(user)
    v := reflect.ValueOf(user)
    b.WriteString(`{`)
    //遍历user结构体
    for j := 0; j < t.NumField(); j++ {
        var stringVal string
        if val, ok := v.Field(j).Interface().(int); ok {
            stringVal = strconv.Itoa(val)
        }else {
            stringVal = v.Field(j).Interface().(string)
        }
        //拼接json
        b.WriteString(`"`)
        b.WriteString(t.Field(j).Name)
        b.WriteString(`": "`)
        b.WriteString(stringVal)
        if j == t.NumField()-1 {
            b.WriteString(`"`)
        }else {
            b.WriteString(`",`)
        }
    }
    b.WriteString(`}`)
    //set up the request object
    req := esapi.IndexRequest{
        Index: "zhenai",
        DocumentType: "users",
        DocumentID: strconv.Itoa(i),
        Body: strings.NewReader(b.String()),
        Refresh: "true",
    }
    //perform the request with the client
    res, err := req.Do(context.Background(), client)
    if err != nil {
        return "", err
    }
    defer res.Body.Close()
    //打印字符串结果
    fmt.Println(res.String())
    //采用bufio读取返回数据为byte切片
    bufReader := bufio.NewReader(res.Body)
    content, err := ioutil.ReadAll(bufReader)
    if err != nil {
        return "", err
    }
    return handleJsonTwo(content),nil
}

func handleJsonOne(content []byte) string {
    //定义一个result类型变量   json处理方法一
    var data result
    json.Unmarshal(content, &data)
    //取得返回的id
    return data.Id
}

func handleJsonTwo(content []byte) string {
    //创建一个map   json处理方法二
    var jsonObj map[string]interface{}
    //将byte切片映射到指定map上
    json.Unmarshal(content, &jsonObj)
    //取得返回的id
    return jsonObj["_id"].(string)
}

package persist

import (
    "fmt"
    "learn16/model"
    "testing"
)

func TestSave(t *testing.T)  {
    userData := []model.User{
        {Name:"xxxx", Sex:"男", Age:22, MaritalStatus:"注孤生", Address:"asdasd", Height:170, Education: "大学", Wages: "5000", DetailUrl:"www.baidu.com"},
        {Name:"arvin", Sex:"男", Age:18, MaritalStatus:"已婚", Address:"asdasd", Height:170, Education: "大学", Wages: "5000", DetailUrl:"www.baidu.com"},
    }

    for i, user := range userData {
        id, err := save(i, user)
        if err != nil {
            t.Errorf("%s",err)
        }
        fmt.Println(id)
    }
}