golang中常用函数

灰太狼 2022-12-20 14:54 207阅读 0赞

golang一行代码将切片转成以分号分隔的字符串
    https://blog.csdn.net/Sun_Hui_/article/details/106083770
    
    Golang Slice 删除指定的索引(下标）和 slice 清空 等常用操
    https://www.cnblogs.com/egrep/p/10532806.html
    http://www.baiyuxiong.com/?p=1175
    
    
    Golang map字典按值排序
    https://blog.csdn.net/qq_15115793/article/details/88552152
    https://blog.csdn.net/u010983881/article/details/52460998
    
    golang 切片 slice 去掉重复元素
    https://blog.csdn.net/whatday/article/details/109710407
    
    
    //字符串转json对象
    func str2json(jsonstr string) interface{}{
    	//cmd := "['read': 2.0, 'write': 1.2}, {'read_mb': 4.0, 'write': 3.2}]"
    	str := strings.Replace(string(jsonstr), "'", "\"", -1)
    	str = strings.Replace(str, "\n", "", -1)
    
    	var dat interface{}
    	if err := json.Unmarshal([]byte(str), &dat); err == nil {
    		return dat
    	} else {
    		return "0"
    	}
    }
    
    //遍历数组中所有元素追加成string
    func arrayToString(arr []string) string {
    	var result string
    	for _, i := range arr {
    		result += i
    	}
    	return result
    }
    
    //判断文件是否存在，存在则返回true,不存在则返回false
    func checkFileIsExist(filename string) bool  {
    	var exist = true
    	if _, err := os.Stat(filename); os.IsNotExist(err) {
    		exist = false
    	}
    	return exist
    }
    
    //将int64转换为int
    func int64toint(num int64) int{
    	strInt64 := strconv.FormatInt(num, 10)
    	id16, _ := strconv.Atoi(strInt64)
    	return id16
    }
    //输出错误
    func checkErr(err error) {
    	if err != nil {
    		panic(err)
    	}
    }
    
    //字节数组转string
    func byte2String(p []byte) string {
    	return *(*string)(unsafe.Pointer(&p))
    }
    
    //string转字节数组
    func string2byte(s string) []byte {
    	x := (*[2]uintptr)(unsafe.Pointer(&s))
    	h := [3]uintptr{x[0], x[1], x[1]}
    	return *(*[]byte)(unsafe.Pointer(&h))
    }
    
    func post_test() {
    	request_url := "http://xxxxxxxxxxxx/ybtest"
    	// 要 POST的 参数
    	form := url.Values{
    		"username": {"xiaoming"},
    		"address":  {"beijing"},
    		"subject":  {"Hello"},
    		"from":     {"china"},
    	}
    	//对form进行编码
    	body := bytes.NewBufferString(form.Encode())
    	rsp, err := http.Post(request_url, "application/x-www-form-urlencoded", body)
    	if err != nil {
    		panic(err)
    	}
    	defer rsp.Body.Close()
    	body_byte, err := ioutil.ReadAll(rsp.Body)
    	if err != nil {
    		panic(err)
    	}
    	fmt.Println(string(body_byte))
    }
    
    
    func post_data(url string, json string, filename string, filepath string) {
    	var buff bytes.Buffer
    	// 创建一个Writer
    	writer := multipart.NewWriter(&buff)
    
    	// 写入一般的表单字段
    	writer.WriteField("json", json)
    
    	// 写入文件字段
    	if checkFileIsExist(filepath) {
    		// CreateFormFile 第一个参数是表单对应的字段名;第二个字段是对应上传文件的名称
    		w, err := writer.CreateFormFile("file", filename)
    		if err != nil {
    			//创建文件失败
    			checkErr(err)
    			return
    		}
    		data, err := ioutil.ReadFile(filepath)
    		if err != nil {
    			//读取文件发生错误
    			checkErr(err)
    			return
    		}
    		// 把文件内容写入cd
    		w.Write(data)
    	}
    
    	writer.Close()
    
    	// 发送一个POST请求
    	req, err := http.NewRequest("POST", url, &buff)
    	if err != nil {
    		//创建请求失败
    		checkErr(err)
    	}
    
    	// 设置你需要的Header  （这里要特别注意，改成下面json格式就是不行的）
    	req.Header.Set("Content-Type", writer.FormDataContentType())
    	//req.Header.Set("Content-Type", "application/json;charset=UTF-8")
    	//req.Header.Set("Content-Type", "text/html;charset=utf-8")
    	//req.Header.Set("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/85.0.4183.83 Safari/537.36 Edg/85.0.564.44")
    
    	var client http.Client
    	// 执行请求
    	resp, err := client.Do(req)
    	defer resp.Body.Close()
    	// 读取返回内容
    	d, err := ioutil.ReadAll(resp.Body)
    	if err != nil{
    		//读取失败
    		checkErr(err)
    		return
    	}
    
    	fmt.Println(string(d))
    
    }
    
    
    //获取当前最大已经消费完的最大ID
    func getCurrId(logpath string) string {
    	var f *os.File
    	var err1 error
    	max_id := "0"
    	if checkFileIsExist(logpath) { //如果文件存在
    		f, err1 = os.Open(logpath) //打开文件
    		reader := bufio.NewReader(f) // 创建带缓冲的读取器
    		for {
    			str, err := reader.ReadString('\n')
    			if err == nil && str !="" {
    				max_id = strings.Replace(str, "\n", "", -1)
    				max_id = strings.Replace(max_id, "\\n", "", -1)
    				break
    			}
    		}
    		f.Close()
    	} else {
    		f, err1 = os.Create(logpath) //创建文件
    		n, err := io.WriteString(f, "0\n") //写入文件(字符串)
    		_ = n
    		checkErr(err)
    		f.Close()
    	}
    	checkErr(err1)
    	return max_id
    }
    
    //将消费完的最大ID写入文件
    func writeFile(logpath string, num int) bool {
    	var f *os.File
    	f, err := os.OpenFile(logpath,os.O_WRONLY|os.O_TRUNC,0666) //打开文件
    	if err != nil {
    		checkErr(err)
    		return false
    	}
    	n, err := io.WriteString(f, strconv.Itoa(num)+"\n") //写入文件(字符串)
    	if err != nil {
    		checkErr(err)
    		return false
    	}
    	_ = n
    	f.Close()
    	return true
    }