Object Storage Service:Manage file metadata (Harmony SDK)

Notas de uso

• Para obter mais informações sobre regiões e endpoints, consulte Regiões e endpoints.

• Para definir metadados de objeto, é necessária a permissão oss:PutObject. Para consultar metadados de objeto, é necessária a permissão oss:GetObject. Para mais informações, consulte Conceder permissões personalizadas a um usuário do RAM.

Configure metadados de objeto ao fazer upload de um objeto

O exemplo de código a seguir demonstra como definir a lista de controle de acesso (ACL) do objeto como leitura pública durante o upload:

import Client, { EObjectAcl, RequestError } from '@aliyun/oss';

// Create an OSSClient instance.
const client = new Client({
  // Specify the AccessKey ID obtained from Security Token Service (STS).
  accessKeyId: 'yourAccessKeyId',
  // Specify the AccessKey secret obtained from STS.
  accessKeySecret: 'yourAccessKeySecret',
  // Specify the security token obtained from STS.
  securityToken: 'yourSecurityToken',
  // Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to oss-cn-hangzhou.
  region: 'oss-cn-hangzhou',
});

const bucket = 'yourBucketName'; // Specify the name of the bucket.

const key='yourObjectName '; // Specify the name of the object.

const putObject = async () => {
  try {
    // Use the putObject method to upload data to object in the specified bucket and pass parameters.
    const res = await client.putObject({
      bucket, // Specify the name of the bucket.
      key, // Specify the name of the object.
      data: 'hello world' // Specify the data that you want to upload. In this example, a simple string is uploaded.
      objectAcl: EObjectAcl.PRIVATE
    });

    // Display the result of the object upload operation.
    console.log(JSON.stringify(res));
  } catch (err) {
    // Capture exceptions during the request.
    if (err instanceof RequestError) {
      // If known types of errors exist, display information, such as the error code, error message, request ID, HTTP status code, and EC.
      console.log('code: ', err.code);
      console.log('message: ', err.message);
      console.log('requestId: ', err.requestId);
      console.log('status: ', err.status);
      console.log('ec: ', err.ec);
    } else {
      // Display other unknown types of errors.
      console.log('unknown error: ', err);
    }
  }
}

// Call the putObject function to perform the object upload operation.
putObject();

Consulta de metadados de objeto

Use o método HeadObject para recuperar todos os metadados de um objeto

O exemplo de código a seguir ilustra como consultar todos os metadados de um objeto com o método HeadObject:

import Client, { RequestError } from '@aliyun/oss';

// Create an OSSClient instance.
const client = new Client({
  // Specify the AccessKey ID obtained from STS.
  accessKeyId: 'yourAccessKeyId',
  // Specify the AccessKey secret obtained from STS.
  accessKeySecret: 'yourAccessKeySecret',
  // Specify the security token obtained from STS.
  securityToken: 'yourSecurityToken',
  // Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to oss-cn-hangzhou.
  region: 'oss-cn-hangzhou',
});

// Specify the name of the bucket.
const bucket = 'yourBucketName';
// Specify the name of the object.
const key = 'yourObjectName';

/**
 * Query the metadata of the object. 
 * Use the HeadObject method to query the metadata of the object without downloading the object. 
 */
const headObject = async () => {
  try {
    // Use the HeadObject method to query the metadata of the object.
    const res = await client.headObject({
      bucket, // Specify the name of the bucket.
      key, // Specify the name of the object.
    });

    // Display the object metadata.
    console.log(JSON.stringify(res));
  } catch (err) {
    // Capture exceptions during the request.
    if (err instanceof RequestError) {
      // If known types of errors exist, display information, such as the error code, error message, request ID, HTTP status code, and EC.
      console.log('code: ', err.code); // The error code.
      console.log('message: ', err.message); // The error message.
      console.log('requestId: ', err.requestId); // The request ID.
      console.log('status: ', err.status); // The HTTP status code.
      console.log('ec: ', err.ec); // The EC.
    } else {
      // Display other unknown types of errors.
      console.log('unknown error: ', err);
    }
  }
};

// Call the headObject function to query object metadata.
headObject();

Use o GetObjectMeta para obter metadados parciais do objeto

O exemplo de código a seguir apresenta como consultar metadados parciais de um objeto com o método GetObjectMeta:

import Client, { RequestError } from '@aliyun/oss';

// Create an OSSClient instance.
const client = new Client({
  // Specify the AccessKey ID obtained from STS.
  accessKeyId: 'yourAccessKeyId',
  // Specify the AccessKey secret obtained from STS.
  accessKeySecret: 'yourAccessKeySecret',
  // Specify the security token obtained from STS.
  securityToken: 'yourSecurityToken',
  // Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to oss-cn-hangzhou.
  region: 'oss-cn-hangzhou',
});

// Specify the name of the bucket.
const bucket = 'yourBucketName';
// Specify the name of the object.
const key = 'yourObjectName';

/**
 * Query the metadata of the object. 
 * Use the getObjectMeta method to query the metadata of the object, including the HTTP headers. 
 */
const getObjectMeta = async () => {
  try {
    // Use the getObjectMeta method to query the metadata of the object.
    const res = await client.getObjectMeta({
      bucket, // Specify the name of the bucket.
      key, // Specify the name of the object.
    });

    // Display the object metadata.
    console.log(JSON.stringify(res));
  } catch (err) {
    // Capture exceptions during the request.
    if (err instanceof RequestError) {
      // If known types of errors exist, display information, such as the error code, error message, request ID, HTTP status code, and EC.
      console.log('code: ', err.code); // The error code.
      console.log('message: ', err.message); // The error message.
      console.log('requestId: ', err.requestId); // The request ID.
      console.log('status: ', err.status); // The HTTP status code.
      console.log('ec: ', err.ec); // The EC.
    } else {
      // Display other unknown types of errors.
      console.log('unknown error: ', err);
    }
  }
};

// Call the getObjectMeta function to query object metadata.
getObjectMeta();