進度條用於指示上傳或下載的進度。下面的代碼以ossClient.getObject方法為例,介紹如何使用進度條。
static class GetObjectProgressListener implements ProgressListener {
private long bytesRead = 0;
private long totalBytes = -1;
private boolean succeed = false;
@Override
public void progressChanged(ProgressEvent progressEvent) {
long bytes = progressEvent.getBytes();
ProgressEventType eventType = progressEvent.getEventType();
switch (eventType) {
case TRANSFER_STARTED_EVENT:
System.out.println("Start to download......");
break;
case RESPONSE_CONTENT_LENGTH_EVENT:
this.totalBytes = bytes;
System.out.println(this.totalBytes + " bytes in total will be downloaded to a local file");
break;
case RESPONSE_BYTE_TRANSFER_EVENT:
this.bytesRead += bytes;
if (this.totalBytes != -1) {
int percent = (int)(this.bytesRead * 100.0 / this.totalBytes);
System.out.println(bytes + " bytes have been read at this time, download progress: " +
percent + "%(" + this.bytesRead + "/" + this.totalBytes + ")");
} else {
System.out.println(bytes + " bytes have been read at this time, download ratio: unknown" +
"(" + this.bytesRead + "/...)");
}
break;
case TRANSFER_COMPLETED_EVENT:
this.succeed = true;
System.out.println("Succeed to download, " + this.bytesRead + " bytes have been transferred in total");
break;
case TRANSFER_FAILED_EVENT:
System.out.println("Failed to download, " + this.bytesRead + " bytes have been transferred");
break;
default:
break;
}
}
public boolean isSucceed() {
return succeed;
}
}
public static void main(String[] args) {
// Endpoint以杭州為例,其它Region請按實際情況填寫。
String endpoint = "http://oss-cn-hangzhou.aliyuncs.com";
// 阿里雲主帳號AccessKey擁有所有API的存取權限,風險很高。強烈建議您建立並使用RAM帳號進行API訪問或日常運維,請登入 https://ram.console.aliyun.com 建立RAM帳號。
String accessKeyId = "<yourAccessKeyId>";
String accessKeySecret = "<yourAccessKeySecret>";
String bucketName = "<yourBucketName>";
String objectName = "<yourObjectName>";
OSSClient ossClient = new OSSClient(endpoint, accessKeyId, accessKeySecret);
try {
// 帶進度條的下載。
ossClient.getObject(new GetObjectRequest(bucketName, objectName).
<GetObjectRequest>withProgressListener(new GetObjectProgressListener()),
new File("<yourLocalFile>"));
} catch (Exception e) {
e.printStackTrace();
}
// 關閉OSSClient。
ossClient.shutdown();
}
ossClient.putObject、ossClient.getObject和ossClient.uploadPart方法支援進度條功能。ossClient.uploadFile和ossClient.downloadFile方法不支援進度條功能。
下載進度條的完整代碼請參見GitHub。