go语言web开发系列之二十四:用imagemagick为上传图片生成缩略图

一，安装所需的外部程序

1,用apt-get安装ImageMagick

root@ku:/data/liuhongdi/digv23# apt-get install imagemagick

2,查看安装是否成功:

1.  
   root@ku:/data/liuhongdi/digv23# convert --version
2.  
   Version: ImageMagick 6.9.10-23 Q16 x86_64 20190101 https://imagemagick.org
3.  
   Copyright: © 1999-2019 ImageMagick Studio LLC
4.  
   License: https://imagemagick.org/script/license.php
5.  
   Features: Cipher DPC Modules OpenMP
6.  
   Delegates (built-in): bzlib djvu fftw fontconfig freetype jbig jng jp2 jpeg lcms lqr ltdl lzma openexr pangocairo png tiff webp wmf x xml zlib

3,查看convert的默认安装路径:

1.  
   root@ku:/data/liuhongdi/digv23# whereis convert
2.  
   convert: /usr/bin/convert /usr/share/man/man1/convert.1.gz

说明：刘宏缔的go森林是一个专注golang的博客，
          地址：https://blog.csdn.net/weixin_43881017

说明：作者:刘宏缔 邮箱: 371125307@qq.com

二，演示项目的相关信息

1,地址:

https://github.com/liuhongdi/digv24

2,功能：演示go调用shell命令生成缩略图

3,项目结构: 如图:

三，配置文件说明

1,config/config.yaml

1.  
   Server:
2.  
   RunMode: debug
3.  
   HttpPort: 8000
4.  
   ReadTimeout: 60
5.  
   WriteTimeout: 60
6.  
   Log:
7.  
   LogFilePath: /data/gologs/logs
8.  
   LogInfoFileName: info
9.  
   LogWarnFileName: warn
10.  
    LogFileExt: log
11.  
    AccessLog:
12.  
    LogFilePath: /data/gologs/logs
13.  
    LogFileName: access
14.  
    LogFileExt: log
15.  
    Static:
16.  
    StaticDir: /data/liuhongdi/digv24/static
17.  
    ArticleImage:
18.  
    UploadDir: /data/liuhongdi/digv24/static/ware/orig
19.  
    TmbDir: /data/liuhongdi/digv24/static/ware/tmb
20.  
    ImageHost: http://127.0.0.1:8000
21.  
     

说明：

StaticDir:静态文件的保存目录

UploadDir:文章配图的原始图上传后保存目录

TmbDir:  文章配图的缩略图保存目录

ImageHost:访问文章配图url的host

四，go代码说明

1,controller/imageController.go

1.  
   package controller
2.  
    
3.  
   import (
4.  
   "fmt"
5.  
   "github.com/gin-gonic/gin"
6.  
   "github.com/liuhongdi/digv24/global"
7.  
   "github.com/liuhongdi/digv24/pkg/image"
8.  
   "github.com/liuhongdi/digv24/pkg/result"
9.  
   "github.com/liuhongdi/digv24/pkg/validCheck"
10.  
    "github.com/liuhongdi/digv24/request"
11.  
    "strconv"
12.  
    )
13.  
     
14.  
    type ImageController struct{}
15.  
     
16.  
    func NewImageController() ImageController {
17.  
    return ImageController{}
18.  
    }
19.  
    //上传单张图片
20.  
    func (a *ImageController) UploadOne(c *gin.Context) {
21.  
    resultRes := result.NewResult(c)
22.  
    param := request.ArticleRequest{ID: validCheck.StrTo(c.Param("id")).MustUInt64()}
23.  
    valid, errs := validCheck.BindAndValid(c, &param)
24.  
    if !valid {
25.  
    resultRes.Error(400,errs.Error())
26.  
    return
27.  
    }
28.  
     
29.  
    //save image
30.  
    f, err := c.FormFile("f1s")
31.  
    //错误处理
32.  
    if err != nil {
33.  
    fmt.Println(err.Error())
34.  
    resultRes.Error(1,"图片上传失败")
35.  
    } else {
36.  
    //将文件保存至本项目根目录中
37.  
    idstr:=strconv.FormatUint(param.ID, 10)
38.  
    destImage := global.ArticleImageSetting.UploadDir+"/"+idstr+".jpg"
39.  
    err := c.SaveUploadedFile(f, destImage)
40.  
    if (err != nil){
41.  
    fmt.Println("save err:")
42.  
    fmt.Println(err)
43.  
    resultRes.Error(1,"图片保存失败")
44.  
    } else {
45.  
    //make tmb
46.  
    orig:= destImage
47.  
    dest := global.ArticleImageSetting.TmbDir+"/"+idstr+".jpg"
48.  
    err := image.ConvertByLong(orig,dest,300)
49.  
    if (err != nil){
50.  
    fmt.Println(err)
51.  
    }
52.  
    origUrl := global.ArticleImageSetting.ImageHost+"/static/ware/orig/"+idstr+".jpg"
53.  
    tmbUrl := global.ArticleImageSetting.ImageHost+"/static/ware/tmb/"+idstr+".jpg"
54.  
    resultRes.Success(gin.H{"origurl":origUrl,"tmburl":tmbUrl})
55.  
    }
56.  
    }
57.  
    return
58.  
    }

2,pkg/image/convert.go

1.  
   package image
2.  
    
3.  
   import (
4.  
   "bytes"
5.  
   "errors"
6.  
   "fmt"
7.  
   "os/exec"
8.  
   "strconv"
9.  
   )
10.  
     
11.  
    //按指定的图片的长边，生成缩略图
12.  
    func ConvertByLong(orig,dest string,long int) error {
13.  
    longstr := strconv.Itoa(long)
14.  
    cmd := "/usr/bin/convert -size "+longstr+"x"+longstr+" -resize "+longstr+"x"+longstr+" +profile '*' "+orig+" "+dest+" 2>&1"
15.  
    out,err := execShell(cmd)
16.  
    fmt.Println(out)
17.  
    fmt.Println(err)
18.  
    if (err != nil) {
19.  
    return err
20.  
    }
21.  
    if (out != "") {
22.  
    return errors.New(out)
23.  
    }
24.  
    return nil
25.  
    }
26.  
     
27.  
    //执行shell命令
28.  
    func execShell(s string) (string, error){
29.  
    //函数返回一个*Cmd，用于使用给出的参数执行name指定的程序
30.  
    cmd := exec.Command("/bin/bash", "-c", s)
31.  
    var out bytes.Buffer
32.  
    cmd.Stdout = &out
33.  
    err := cmd.Run()
34.  
    //checkErr(err)
35.  
    return out.String(), err
36.  
    }

3,static/upload.html

1.  
   <!DOCTYPE html>
2.  
   <html lang="zh-CN">
3.  
   <head>
4.  
   <title>上传文件示例</title>
5.  
   </head>
6.  
   <body>
7.  
   单文件上传：<br/>
8.  
   <form action="/image/uploadone" method="post" enctype="multipart/form-data">
9.  
   <input type="text" name="id" id="id" placeholder="请输入id" /> <br/>
10.  
    <input type="file" name="f1s" /><br/>
11.  
    <input type="submit" value="上传">
12.  
    </form>
13.  
     
14.  
    </body>
15.  
    </html>

4，其他相关代码可访问github查看

五，测试效果

1,打开上传页面，访问:

http://127.0.0.1:8000/static/upload.html

返回如图:

上传一张图片后返回:

点击tmburl,可以看到缩放为长边300的图片:

六，查看库的版本

1.  
   module github.com/liuhongdi/digv24
2.  
    
3.  
   go 1.15
4.  
    
5.  
   require (
6.  
   github.com/gin-gonic/gin v1.6.3
7.  
   github.com/go-playground/universal-translator v0.17.0
8.  
   github.com/go-playground/validator/v10 v10.2.0
9.  
   github.com/jinzhu/gorm v1.9.16
10.  
    github.com/lestrrat/go-file-rotatelogs v0.0.0-20180223000712-d3151e2a480f
11.  
    github.com/lestrrat/go-strftime v0.0.0-20180220042222-ba3bf9c1d042 // indirect
12.  
    github.com/magiconair/properties v1.8.4 // indirect
13.  
    github.com/mitchellh/mapstructure v1.3.3 // indirect
14.  
    github.com/pelletier/go-toml v1.8.1 // indirect
15.  
    github.com/pkg/errors v0.9.1 // indirect
16.  
    github.com/spf13/afero v1.4.1 // indirect
17.  
    github.com/spf13/cast v1.3.1 // indirect
18.  
    github.com/spf13/jwalterweatherman v1.1.0 // indirect
19.  
    github.com/spf13/pflag v1.0.5 // indirect
20.  
    github.com/spf13/viper v1.7.1
21.  
    go.uber.org/multierr v1.6.0 // indirect
22.  
    go.uber.org/zap v1.16.0
23.  
    golang.org/x/sys v0.0.0-20201119102817-f84b799fce68 // indirect
24.  
    golang.org/x/text v0.3.4 // indirect
25.  
    gopkg.in/ini.v1 v1.62.0 // indirect
26.  
    gopkg.in/yaml.v2 v2.3.0 // indirect
27.  
    )