golang读写常见的文件类型

发表于2019-01-192023-01-12 作者 admin

一、读写xml文件

golang的”encoding/xml”模块有 xml.Unmarshal() 方法和 xml.Marshal() 方法。前者用于格式化读取 xml 文件，后者用于格式化写 xml 文件。操作之前我们先准备一个测试文件notes.xml，内容如下：

<note>
<to>Admin</to>
<from>www.361way.com</from>
<heading>Reminder</heading>
<body>Don't forget me this weekend!</body>
</note>

1、 xml.Unmarshal()读 xml

代码如下：

package main
import (
        "encoding/xml"
        "fmt"
        "io/ioutil"
)
type Notes struct {
        To      string `xml:"to"`
        From    string `xml:"from"`
        Heading string `xml:"heading"`
        Body    string `xml:"body"`
}
func main() {
        data, _ := ioutil.ReadFile("notes.xml")
        note := &Notes{}
        _ = xml.Unmarshal([]byte(data), &note)
        fmt.Println(note.To)
        fmt.Println(note.From)
        fmt.Println(note.Heading)
        fmt.Println(note.Body)
}

上面使用ioutil.ReadFile()方法读取后，返回byte类型的slice类型的文件，然后再交引 Unmarshal进行处理。

2、 xml.Marshal写xml文件

写xml文件的代码如下：

package main
import (
    "encoding/xml"
    "io/ioutil"
)
type notes struct {
    To      string `xml:"to"`
    From    string `xml:"from"`
    Heading string `xml:"heading"`
    Body    string `xml:"body"`
}
func main() {
    note := &notes{To: "Nicky",
        From:    "Rock",
        Heading: "Meeting",
        Body:    "Meeting at 5pm!",
    }
    file, _ := xml.MarshalIndent(note, "", " ")
    _ = ioutil.WriteFile("notes1.xml", file, 0644)
}

二、读写json文件

之前也写过处理json文件的总结：https://www.361way.com/go-json/5859.html ，本篇这里再搞两个示例，本篇写json文件使用的json.MarshalIndent方法，读文件使用的json.Unmarshal方法。

1、写json文件

package main
import (
    "encoding/json"
    "io/ioutil"
)
type Salary struct {
        Basic, HRA, TA float64
    }
type Employee struct {
    FirstName, LastName, Email string
    Age                        int
    MonthlySalary              []Salary
}
func main() {
    data := Employee{
        FirstName: "Mark",
        LastName:  "Jones",
        Email:     "mark@gmail.com",
        Age:       25,
        MonthlySalary: []Salary{
            Salary{
                Basic: 15000.00,
                HRA:   5000.00,
                TA:    2000.00,
            },
            Salary{
                Basic: 16000.00,
                HRA:   5000.00,
                TA:    2100.00,
            },
            Salary{
                Basic: 17000.00,
                HRA:   5000.00,
                TA:    2200.00,
            },
        },
    }
    file, _ := json.MarshalIndent(data, "", " ")
    _ = ioutil.WriteFile("test.json", file, 0644)
}

2、读json文件

package main
import (
    "encoding/json"
    "fmt"
    "io/ioutil"
)
type CatlogNodes struct {
    CatlogNodes []Catlog `json:"catlog_nodes"`
}
type Catlog struct {
    Product_id string `json: "product_id"`
    Quantity   int    `json: "quantity"`
}
func main() {
    file, _ := ioutil.ReadFile("test.json")
    data := CatlogNodes{}
    _ = json.Unmarshal([]byte(file), &data)
    for i := 0; i < len(data.CatlogNodes); i++ {
        fmt.Println("Product Id: ", data.CatlogNodes[i].Product_id)
        fmt.Println("Quantity: ", data.CatlogNodes[i].Quantity)
    }
}

三、读写文本文件

1、写文本文件

package main
import (
    "bufio"
    "log"
    "os"
)
func main() {
    sampledata := []string{"Lorem ipsum dolor sit amet, consectetur adipiscing elit.",
        "Nunc a mi dapibus, faucibus mauris eu, fermentum ligula.",
        "Donec in mauris ut justo eleifend dapibus.",
        "Donec eu erat sit amet velit auctor tempus id eget mauris.",
    }
    file, err := os.OpenFile("test.txt", os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
    if err != nil {
        log.Fatalf("failed creating file: %s", err)
    }
    datawriter := bufio.NewWriter(file)
    for _, data := range sampledata {
        _, _ = datawriter.WriteString(data + "\n")
    }
    datawriter.Flush()
    file.Close()
}

2、读text文件

package main
import (
    "bufio"
    "fmt"
    "log"
    "os"
)
func main() {
    file, err := os.Open("test.txt")
    if err != nil {
        log.Fatalf("failed opening file: %s", err)
    }
    scanner := bufio.NewScanner(file)
    scanner.Split(bufio.ScanLines)
    var txtlines []string
    for scanner.Scan() {
        txtlines = append(txtlines, scanner.Text())
    }
    file.Close()
    for _, eachline := range txtlines {
        fmt.Println(eachline)
    }
}

四、读写csv文件

1、写csv文件

package main
import (
    "encoding/csv"
    "log"
    "os"
)
func main() {
    rows := [][]string{
        {"Name", "City", "Language"},
        {"Pinky", "London", "Python"},
        {"Nicky", "Paris", "Golang"},
        {"Micky", "Tokyo", "Php"},
    }
    csvfile, err := os.Create("test.csv")
    if err != nil {
        log.Fatalf("failed creating file: %s", err)
    }
    csvwriter := csv.NewWriter(csvfile)
    for _, row := range rows {
        _ = csvwriter.Write(row)
    }
    csvwriter.Flush()
    csvfile.Close()
}

2、读csv文件

package main
import (
    "bufio"
    "fmt"
    "log"
    "os"
)
func main() {
    file, err := os.Open("test.csv")
    if err != nil {
        log.Fatalf("failed opening file: %s", err)
    }
    scanner := bufio.NewScanner(file)
    scanner.Split(bufio.ScanLines)
    var txtlines []string
    for scanner.Scan() {
        txtlines = append(txtlines, scanner.Text())
    }
    file.Close()
    for _, eachline := range txtlines {
        fmt.Println(eachline)
    }
}