cos.getObject({
    Bucket: 'examplebucket-1250000000', /* Enter your own bucket, required field */
    Region: 'COS_REGION',  /* The region where the bucket is located, such as ap-beijing, required field */
    Key: '1.jpg',  /* The object key stored in the bucket (e.g., 1.jpg, a/b/test.txt), required field */
    onProgress: function (progressData) {
        console.log(JSON.stringify(progressData));
}
            }, function(err, data) {
    console.log(err || data.Body);
    });

cos.getObject({
    Bucket: 'examplebucket-1250000000', /* Enter your own bucket, required field */
    Region: 'COS_REGION',  /* The region where the bucket is located, such as ap-beijing, required field */
    Key: '1.jpg',  /* The object key stored in the bucket (e.g., 1.jpg, a/b/test.txt), required field */
    Range: 'bytes=1-3',        /* Optional */
    onProgress: function (progressData) {
        console.log(JSON.stringify(progressData));
}
            }, function(err, data) {
    console.log(err || data.Body);
    });

cos.getObject({
    Bucket: 'examplebucket-1250000000', /* Required */
    Region: 'COS_REGION',     /* The region where the bucket is located, required field */
    Key: 'exampleobject',              /* Required */
    DataType: 'blob',        /* Optional */
    onProgress: function (progressData) {
        console.log(JSON.stringify(progressData));
}
            }, function(err, data) {
    console.log(err || data.Body);
    });

cos.getObject({
    Bucket: 'examplebucket-1250000000', /* Enter your own bucket, required field */
    Region: 'COS_REGION',  /* The region where the bucket is located, such as ap-beijing, required field */
    Key: '1.jpg',  /* The object key stored in the bucket (e.g., 1.jpg, a/b/test.txt), required field */
    Headers: {
      'x-cos-traffic-limit': 819200, // The valid range for the limit value is 819,200 - 838,860,800, with the default unit being bit/s, i.e., 800Kb/s - 800Mb/s. If it exceeds this range, a 400 error will be returned.
    },
    onProgress: function (progressData) {
        console.log(JSON.stringify(progressData));
}
            }, function(err, data) {
    console.log(err || data.Body);
    });

function(err, data) { ... }


var getObjects = function (marker) {
    cos.getBucket({
              Bucket: config.Bucket,
              Region: config.Region,
        Prefix: 'abc', /* The directory to download, or the prefix of the files to download */
        Marker: marker,
        MaxKeys: 1000,
    }, function (listError, listResult) {
        if (listError) return console.log('list error:', listError);
        var nextMarker = listResult.NextMarker;
        listResult.Contents.forEach(function (item) {
            cos.getObjectUrl({
              Bucket: config.Bucket,
              Region: config.Region,
              Key: item.Key,
            }, function(err, data) {
              if (err) return console.log(err);
              setTimeout(() => {
                var downloadUrl = data.Url + (data.Url.indexOf('?') > -1 ? '&' : '?') + 'response-content-disposition=attachment'; // Add the parameter for forced download
                window.open(downloadUrl); // This opens the URL in a new window. If you need to open it in the current window, you can use a hidden iframe to download or use the "a" tag with the download attribute to assist in downloading.
              }, 500);
    });
    });
        // If not all files have been processed, continue to query the next page of the file list
        if (listResult.IsTruncated === 'true') getMultipleObjects(nextMarker);
    });
}
getObjects();