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Golang操作elasticsearch

  • 使用第三方包:olivere github。总结一下olivere操作ES的常用功能,方便查阅。
  • 说明:以下例子用到的es index:"test", es type:"test", es address: "http://10.1.1.1:9200"
  1. 新建es client

    func ESClient() (client *elastic.Client,err error){
        file := "./log.log"
        logFile, _ := os.OpenFile(file, os.O_RDWR|os.O_CREATE|os.O_APPEND, 0766) // 应该判断error,此处简略
        cfg := []elastic.ClientOptionFunc{
            elastic.SetURL("http://10.1.1.1:9200"),
            elastic.SetSniff(false),
            elastic.SetInfoLog(log.New(logFile, "ES-INFO: ", 0)),
            elastic.SetTraceLog(log.New(logFile, "ES-TRACE: ", 0)),
            elastic.SetErrorLog(log.New(logFile, "ES-ERROR: ", 0)),
        }
        client,err =elastic.NewClient(cfg ...)
        return
    }
  2. 查看某文档是否存在,给定文档ID查询

    func isExists(id string)bool{
        client,_ := ESClient()
        defer client.Stop()
        exist,_ := client.Exists().Index("test").Type("test").Id(id).Do(context.Background())
        if !exist{
            log.Println("ID may be incorrect! ",id)
            return false
        }
        return true
    }
  3. 获取某文档的内容

    func(doc *myDocument) Get(id string){
        client ,_:= ESClient()
        defer client.Stop() 
        if !isExists(id){
            return
        }
        esResponse,err := client.Get().Index("test").Type("test").Id(id).Do(context.Background())
        if err != nil {
            // Handle Error
            return
        }
        json.Unmarshal(*esResponse.Source,&doc)
    }
  4. 新增文档

    func(doc *myDocument) Add(id string){
        client ,_:= ESClient()
        defer client.Stop() 
        if !isExists(id){
            return
        }
        client.Index().Index("test").Type("test").Id(id).BodyJson(doc).Do(context.Background())
    }
  5. 批量新增

    func BulkAdd(docs []myDocument){
        bulkRequest := seriesClient.Bulk()
        client ,_:= ESClient()
        defer client.Stop()
        for _,doc := range docs{
            esRequest := elastic.NewBulkIndexRequest().Index("test").Type("test").Id(id).Doc(doc)
            bulkRequest = bulkRequest.Add(esRequest)
        }
        bulkRequest.Do(context.Background())
    }
  6. 更新文档

    func Update(updateField *map[string]interface{},id string){
        client ,_:= ESClient()
        defer client.Stop()
        if !isExists(id){
            return
        }
        _,err:=client.Update().Index("test").Type("test").Id(id).Doc(updateField).Do(context.Background())
        if err != nil{
            //Handle Error
        }
    }
  7. 删除文档

    func Delete(id string){
        client ,_:= ESClient()
        defer client.Stop()
        if !isExists(id){
            return
        }
        _,err:=client.Delete().Index("test").Type("test").Id(id).Do(context.Background())
        if err != nil{
            //Handle Error
        }
    }
  8. 搜索文档(搜索是ES非常引以为傲的功能,以下示例是相对复杂的查询条件,需将查询结果排序,按页返回)

    func Search(criteria *SearchCriteria)(docs []myDocument){
        client ,_:= ESClient()
        defer client.Stop()
        query := elastic.NewBoolQuery()
        query = query.Must(elastic.NewTermQuery("category",criteria.Category))
        query=query.Must(elastic.NewMatchQuery("title",criteria.Title))
        query=query.Must(elastic.NewRangeQuery("update_timestamp").Gte(criteria.UpdateTime))
        esResponse,_ :=client.Search().Index("test").Type("test").
            Query(query).Sort(criteria.Sort,criteria.Order=="ASC"||criteria.Order=="asc").
            From(criteria.Offset).Size(criteria.Limit).Do(context.Background())
        for _,value:= range esResponse.Hits.Hits{
            var doc *myDocument
            json.Unmarshal(*value.Source,&doc)
            docs = append(docs,doc)
        }
        return
    }
    
    type SearchCriteria struct{
        Category string `json:"category"`
        Limit int `json:"limit"`
        Offset int `json:"offset"`
        Title string `json:"title"`
        UpdateTime int64 `json:"update_timestamp"`
        Order string `json:"order"`
        Sort string `json:"sort"`
    }

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