从mongodb中检索到一个数组对象。数据如下：
[{
1
fruits
Apple
Apple is my favorite fruit.
}
{
2
colors
Red
Red color is always charming.
}
{
3
flowers
Lotus
It is one of the most beautiful flowers in this world.
}]
这是用于检索上述数据的代码。struct是：
type Item struct {
Id int `json:"id"`
Category string `json:"category"`
Name string `json:"name"`
Description string `json:"description"`
}
type Items []Item
func GetData(Query interface{}) (result Items, err error) {
mongoSession := ConnectDb()
sessionCopy := mongoSession.Copy()
defer sessionCopy.Close()
getCollection := mongoSession.DB("custom").C("custom")
err = getCollection.Find(Query).All(&result)
if err != nil {
return result, err
}
return result, nil
}
/*
* Retrieve the data used by main function
*/
func retrieve(c *gin.Context) {
//mongoSession := ConnectDb()
conditions := bson.M{}
data, err :=GetData(conditions)
if err != nil {
fmt.Println("There is somthing wrong")
}
arrange(data)
return
}
func arrange(data Items) {
pagesJson, err := json.Marshal(data)
if err != nil {
log.Fatal("Cannot encode to JSON ", err)
}
fmt.Println(string(pagesJson))
}
运行json.Marshal，输出如下所示：
[{
"id":1,
"category":"fruits",
"name":"Apple",
"description":"Apple is my favorite fruit."
},
{
"id":2,
"category":"colors",
"name":"Red",
"description":"Red color is always charming."
},
{
"id":3,
"category":"flowers",
"name":"Lotus",
"description":"It is one of the most beautiful flowers in this world."
}]
预期产量
{
"id":1,
"category":"fruits",
"name":"Apple",
"description":"Apple is my favorite fruit."
}
{
"id":2,
"category":"colors",
"name":"Red",
"description":"Red color is always charming."
}
{
"id":3,
"category":"flowers",
"name":"Lotus",
"description":"It is one of the most beautiful flowers in this world."
}
问题是数据在数组对象中供我使用，我需要{}如上所述的String结构数据。我之前曾发布过此问题，但未获得任何成功答案。我从很多时候开始尝试，请帮助我。
根据OP讨论的内容，将结构编组Items将得到以下结果：
[{
"id":1,
"category":"fruits",
"name":"Apple",
"description":"Apple is my favorite fruit."
},
{
"id":2,
"category":"colors",
"name":"Red",
"description":"Red color is always charming."
},
{
"id":3,
"category":"flowers",
"name":"Lotus",
"description":"It is one of the most beautiful flowers in this world."
}]
通过此操作，OP希望获得一个类似于以下内容的字符串：
{
"id":1,
"category":"fruits",
"name":"Apple",
"description":"Apple is my favorite fruit."
},
{
"id":2,
"category":"colors",
"name":"Red",
"description":"Red color is always charming."
},
{
"id":3,
"category":"flowers",
"name":"Lotus",
"description":"It is one of the most beautiful flowers in this world."
}
我考虑了两种方法：
遍历项目并将每个封送处理的项目附加到字符串中（显然效率不高）
func getMyString(items Items) (string, error) {
var buffer bytes.Buffer
var err error
var b []byte
for _, item := range items {
b, err = json.Marshal(item)
if err != nil {
return "", err
}
buffer.WriteString(string(b) + ",")
}
s := strings.TrimSpace(buffer.String())
// trim last comma
s = s[:len(s)-1]
return s, nil
}
或只是修剪前和后方括号：
func getMyString2(items Items) (string, error) {
b, err := json.Marshal(items)
if err != nil {
return "", err
}
s := string(b)
s = strings.TrimSpace(s)
// trim leading and trailing spaces
s = s[1 : len(s)-1]
return s, nil
}
链接到代码：https : //play.golang.org/p/F1SUYJZEn_n
编辑：由于OP希望将其分隔开，因此我修改了方法1来满足要求：
func getMyString(items Items) (string, error) {
var buffer bytes.Buffer
var err error
var b []byte
for _, item := range items {
b, err = json.Marshal(item)
if err != nil {
return "", err
}
// use space to separate each json string in the array
buffer.WriteString(string(b) + " ")
}
s := strings.TrimSpace(buffer.String())
return s, nil
}
链接到新代码：https : //play.golang.org/p/dVvsQlsRqZO
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