Manage object metadata

Configure object metadata

You can configure the metadata of an object when you upload the object. The following table describes the metadata that you can configure.

The following code provides an example on how to configure object metadata:

package main

import (
    "fmt"
    "os"
    "time"
    "strings"
    "github.com/aliyun/aliyun-oss-go-sdk/oss"
)

func main() {
    // Create an OSSClient instance.
    client, err := oss.New("<yourEndpoint>", "<yourAccessKeyId>", "<yourAccessKeySecret>")
    if err ! = nil {
        fmt.Println("Error:", err)
        os.Exit(-1)
    }

    // Obtain the bucket.    bucket, err := client.Bucket("<yourBucketName>")
    if err ! = nil {
        fmt.Println("Error:", err)
        os.Exit(-1)
    }

    //  Configure object metadata: Set the expiration time to 2049-01-10, 23:00:00 in GMT format, ACL to public read, and MyProp to MyPropVal as user metadata.
    expires := time.Date(2049, time.January, 10, 23, 0, 0, 0, time.UTC)
    options := []oss.Option{
        oss.Expires(expires),
        oss.ObjectACL(oss.ACLPublicRead),
        oss.Meta("MyProp", "MyPropVal"),
    }

    // Use a data stream to upload the object.
    err = bucket.PutObject("<yourObjectName>", strings.NewReader("MyObjectValue"), options...)
    if err ! = nil {
        fmt.Println("Error:", err)
        os.Exit(-1)
    }

    // Obtain the object metadata.
    props, err := bucket.GetObjectDetailedMeta("<yourObjectName>")
    if err ! = nil {
        fmt.Println("Error:", err)
        os.Exit(-1)
    }
    fmt.Println("Object Meta:", props)
}
			

Modify object metadata

The following code provides an example on how to modify one or multiple object metadata parameters at a time:

package main

import (
    "fmt"
    "os"
    "github.com/aliyun/aliyun-oss-go-sdk/oss"
)

func main() {
    // Create an OSSClient instance.
    client, err := oss.New("<yourEndpoint>", "<yourAccessKeyId>", "<yourAccessKeySecret>")
    if err ! = nil {
        fmt.Println("Error:", err)
        os.Exit(-1)
    }

    bucketName := "<yourBucketName>"
    objectName := "<yourObjectName>"

    // Obtain the bucket.
    bucket, err := client.Bucket(bucketName)
    if err ! = nil {
        fmt.Println("Error:", err)
        os.Exit(-1)
    }

    // Modify one object metadata parameter at a time.
    err = bucket.SetObjectMeta(objectName, oss.Meta("MyMeta", "MyMetaValue1"))
    if err ! = nil {
        fmt.Println("Error:", err)
        os.Exit(-1)
    }

    // Modify multiple object metadata parameters at a time.
    options := []oss.Option{
        oss.Meta("MyMeta", "MyMetaValue2"),
        oss.Meta("MyObjectLocation", "HangZhou"),
    }
    err = bucket.SetObjectMeta(objectName, options...)
    if err ! = nil {
        fmt.Println("Error:", err)
        os.Exit(-1)
    }

    // Obtain the object metadata.
    props, err := bucket.GetObjectDetailedMeta(objectName)
    if err ! = nil {
        fmt.Println("Error:", err)
        os.Exit(-1)
    }
    fmt.Println("Object Meta:", props)
}
			

Obtain object metadata

The following code provides an example on how to obtain object metadata:

package main

import (
    "fmt"
    "os"
    "github.com/aliyun/aliyun-oss-go-sdk/oss"
)

func main() {
    // Create an OSSClient instance.
    client, err := oss.New("<yourEndpoint>", "<yourAccessKeyId>", "<yourAccessKeySecret>")
    if err ! = nil {
        fmt.Println("Error:", err)
        os.Exit(-1)
    }

    bucketName := "<yourBucketName>"
    objectName := "<yourObjectName>"

    // Obtain the bucket.
    bucket, err := client.Bucket(bucketName)
    if err ! = nil {
        fmt.Println("Error:", err)
        os.Exit(-1)
    }

    // Obtain the object metadata.
    props, err := bucket.GetObjectDetailedMeta(objectName)
    if err ! = nil {
        fmt.Println("Error:", err)
        os.Exit(-1)
    }
    fmt.Println("Object Meta:", props)
}