feat: download-image 接口

backend/controller/postapi.go

@@ -1,6 +1,8 @@
 package controller
 
 import (
+	"bytes"
+
 	"github.com/RockChinQ/Campux/backend/service"
 	"github.com/gin-gonic/gin"
 )
@@ -20,6 +22,8 @@ func NewPostRouter(rg *gin.RouterGroup, ps service.PostService) *PostRouter {
 	// bind routes
 	group.POST("/upload-image", pr.UploadImage)
 	group.POST("/post-new", pr.PostNew)
+	// download-image/{image-key}
+	group.GET("/download-image/:key", pr.DownloadImage)
 
 	return pr
 }
@@ -85,3 +89,30 @@ func (pr *PostRouter) PostNew(c *gin.Context) {
 		"id": id,
 	})
 }
+
+// 下载图片
+func (pr *PostRouter) DownloadImage(c *gin.Context) {
+	_, err := pr.GetUin(c)
+
+	if err != nil {
+		pr.StatusCode(c, 401, err.Error())
+		return
+	}
+
+	key := c.Param("key")
+
+	buf := bytes.NewBuffer(nil)
+
+	err = pr.PostService.DownloadImage(key, buf)
+
+	if err != nil {
+		pr.Fail(c, 1, err.Error())
+		return
+	}
+
+	// 下载图片，直接返回内容
+	// data, err := pr.PostService.DownloadImage(key)
+	c.Writer.Header().Set("Content-Type", "image/jpeg")
+
+	c.Data(200, "application/octet-stream", buf.Bytes())
+}

backend/oss/minio.go

@@ -53,3 +53,16 @@ func (m *MinioClient) UploadFromIO(ioReader io.Reader, suffix string) (string, e
 	_, err := m.Client.PutObject(context.Background(), m.Bucket, objectName, ioReader, -1, minio.PutObjectOptions{})
 	return objectName, err
 }
+
+// 下载文件到io.Writer
+func (m *MinioClient) DownloadToIO(objectName string, ioWriter io.Writer) error {
+	obj, err := m.Client.GetObject(context.Background(), m.Bucket, objectName, minio.GetObjectOptions{})
+
+	if err != nil {
+		return err
+	}
+
+	_, err = io.Copy(ioWriter, obj)
+
+	return err
+}

backend/service/post.go

@@ -30,6 +30,10 @@ func (ps *PostService) UploadImage(ioReader io.Reader, suffix string) (string, e
 	return ps.OSS.UploadFromIO(ioReader, suffix)
 }
 
+func (ps *PostService) DownloadImage(key string, ioWriter io.Writer) error {
+	return ps.OSS.DownloadToIO(key, ioWriter)
+}
+
 func (ps *PostService) PostNew(uuid string, uin int64, text string, images []string, anon bool) (int, error) {
 
 	id, err := ps.DB.CountPost()