Preparations

1. The object concatenation feature is implemented via Serverless Cloud Function (SCF). Before using it, you need to go to the COS console to create an object concatenation function on Application Integration - Object Concatenation.
2. After creating the function, set the function parameters according to the instructions in the operation column of the function list. The parameters are in JSON string format and detailed below.
   • If you select SCF authentication for the function, you need to call the Invoke API provided by SCF to run the object concatenation function, where the ClientContext parameter is passed in JSON format. For more information, please see Function Parameter Configuration Sample.
   • If you configure the function to be authentication free, you can directly send HTTP requests to the corresponding API to call the function.

Function Parameter Configuration Sample

Note：

In actual practice, delete the comments in the code.

{
  "bucket": "examplebucket-1250000000",    // Bucket of the output merged file for final delivery
  "region": "ap-guangzhou",         // Region of the bucket of the output merged file for final delivery
  "key": "concat.txt",              // Name of the output merged file for final delivery
   /**
   * `sourceList` specifies the list of source files that need to be packaged and is a JSON array.
   * Each item contains information such as the source file URL, and more parameters may be extended in the future.
   * 
   * If the source file list is excessively long, you can convert the value of `sourceList` into a JSON string,
   * write the JSON string into a .json file, upload the file to COS, and specify the URL of the file in the `sourceConfigList` parameter.
   * 
   * You only need to specify either `sourceList` or `sourceConfigList`.
   */
  "sourceList": [
      {
          "url": "https://examplebucket-1250000000.cos.ap-guangzhou.myqcloud.com/file1.txt"
      },
      {
          "url": "https://examplebucket-1250000000.cos.ap-guangzhou.myqcloud.com/file2.txt"
      },
      {
          "url": "https://examplebucket-1250000000.cos.ap-guangzhou.myqcloud.com/file3.txt"
      }
  ],
  "sourceConfigList": [
      {
           "url": "https://examplebucket-1250000000.cos.ap-guangzhou.myqcloud.com/sourceList.json"
      }
  ]
}

The parameters are described as follows:

Function Response Sample

{
   "code": 0,
   "message": "cos concat file success",
   "data": {
       "Location": "examplebucket-1250000000.cos.ap-guangzhou.myqcloud.com/concat.txt",
       "Bucket": "examplebucket-1250000000",
       "Key": "concat.txt",
       "ETag": "\"152958e4f4bfded94c0b30f03343d6b8-1\""
   }
}

Response parameters are described as follows:

Example

Parameter configuration

{
 "bucket": "examplebucket-1250000000",
 "region": "ap-guangzhou",
 "key": "concat.txt",
 "sourceList": [
     {
         "url": "https://examplebucket-1250000000.cos.ap-guangzhou.myqcloud.com/file1.txt"
     },
     {
         "url": "https://examplebucket-1250000000.cos.ap-guangzhou.myqcloud.com/file2.txt"
     },
     {
         "url": "https://examplebucket-1250000000.cos.ap-guangzhou.myqcloud.com/file3.txt"
     }
 ]
}

Structure of the final output of object concatenation

concat.txt
  ├── content of file1.txt
  ├── content of file2.txt
  └── content of file3.txt