Object Storage Service:Prevent overwriting objects with the same name (Node.js SDK)

Simple upload

The following sample code provides an example on how to prevent existing objects from being overwritten by objects that have the same names when you perform simple upload:

const OSS = require("ali-oss");

const client = new OSS({
  // Set region to the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set region to oss-cn-hangzhou.
  region: 'yourregion',
  // Obtain access credentials from environment variables. Before running the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are set.
  accessKeyId: process.env.OSS_ACCESS_KEY_ID,
  accessKeySecret: process.env.OSS_ACCESS_KEY_SECRET,
  authorizationV4: true,
  // Specify the bucket name.
  bucket: 'examplebucket'
});

// Set yourLocalFile to the full path of the local file.
const file = "yourLocalFile";
// Specify whether to overwrite an existing object that has the same name. In this example, this parameter is set to true to prevent overwriting. If an object with the same name exists, the program reports an error.
const headers = {
  "x-oss-forbid-overwrite": true,
};
async function put() {
  try {
    // Set yourObjectName to the full path of the object.
    const result = await client.put("yourObjectName", file, { headers });
    console.log(result);
  } catch (e) {
    console.log(e);
  }
}

put();

Copy an object

const OSS = require("ali-oss");

const client = new OSS({
  // Set region to the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set region to oss-cn-hangzhou.
  region: 'yourregion',
  // Obtain access credentials from environment variables. Before running the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are set.
  accessKeyId: process.env.OSS_ACCESS_KEY_ID,
  accessKeySecret: process.env.OSS_ACCESS_KEY_SECRET,
  authorizationV4: true,
  // Specify the bucket name.
  bucket: 'examplebucket'
});

// Specify whether to overwrite an existing object that has the same name. In this example, this parameter is set to true to prevent overwriting. If an object with the same name exists, the program reports an error.
const headers = {
  "x-oss-forbid-overwrite": true,
};
// Set yourTargetObject to the full path of the destination object.
// Set yourSourceObject to the full path of the source object.
client  
  .copy("yourTargetObject", "yourSourceObject", { headers })
  .then((res) => {
    console.log(res.res.data.toString("utf8"));
    console.log(res);
  })
  .catch((e) => {
    console.log(e);
  });

const OSS = require("ali-oss");

const client = new OSS({
  // Set yourRegion to the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set region to oss-cn-hangzhou.
  region: "yourRegion",
  // Obtain access credentials from environment variables. Before running the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are set.
  accessKeyId: process.env.OSS_ACCESS_KEY_ID,
  accessKeySecret: process.env.OSS_ACCESS_KEY_SECRET,
  authorizationV4: true,
  // Set yourTargetBucket to the name of the bucket where the destination object is located.
  bucket: "yourTargetBucket"
});

async function put() {
  try {
    const result = await client.multipartUploadCopy(
      // Specify the full path of the destination object.
      "yourTargetObject",
      {
        // Specify the full path of the source object to copy.
        sourceKey: "yourSourceObject",
        // Specify the name of the bucket where the source object is located.
        sourceBucketName: "yourSourceBucket",
      },
      {
        // Specify whether to overwrite an existing object that has the same name. In this example, this parameter is set to true to prevent overwriting. If an object with the same name exists, the program reports an error.
        headers: { "x-oss-forbid-overwrite": true },
      }
    );
    console.log(result);
  } catch (e) {
    console.log(e);
  }
}

put();

Multipart upload

The following sample code provides an example on how to prevent an existing object from being overwritten by an object with the same name when you use multipart upload to upload the object:

const OSS = require("ali-oss");

const client = new OSS({
  // Set yourRegion to the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set region to oss-cn-hangzhou.
  region: "yourRegion",
  // Obtain access credentials from environment variables. Before running the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are set.
  accessKeyId: process.env.OSS_ACCESS_KEY_ID,
  accessKeySecret: process.env.OSS_ACCESS_KEY_SECRET,
  authorizationV4: true,
  // Set yourBucketName to the name of the bucket.
  bucket: "yourBucketName",
});

// Set yourLocalFile to the full path of the local file.
const file = "yourLocalFile";
// Specify whether to overwrite an existing object that has the same name. In this example, this parameter is set to true to prevent overwriting. If an object with the same name exists, the program reports an error.
const headers = {
  "x-oss-forbid-overwrite": true,
};
{
  // Perform a multipart upload. Set yourObjectName to the full path of the object.
  client    
    .multipartUpload("yourObjectName", file, { headers })
    .then((res) => {
      console.log(res);
    })
    .catch((e) => {
      console.log(e);
    });
}

References

• For more information about the simple upload API operation, see PutObject.

• For more information about the object copy API operation, see CopyObject.

• For more information about the multipart upload API operations, see InitiateMultipartUpload and CompleteMultipartUpload.