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Java进度条

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进度条用于指示上传或下载文件的进度。本文以ossClient.putObject方法为例,介绍如何使用进度条。

注意事项

  • 本文以华东1(杭州)外网Endpoint为例。如果您希望通过与OSS同地域的其他阿里云产品访问OSS,请使用内网Endpoint。关于OSS支持的Region与Endpoint的对应关系,请参见访问域名和数据中心

  • 本文以从环境变量读取访问凭证为例。如何配置访问凭证,请参见Java配置访问凭证

  • 本文以OSS域名新建OSSClient为例。如果您希望通过自定义域名、STS等方式新建OSSClient,请参见新建OSSClient

示例代码

以下代码用于演示通过ossClient.putObject上传文件时使用进度条的方法:

说明

ossClient.putObject、ossClient.getObject、ossClient.uploadPart、ossClient.uploadFile以及ossClient.downloadFile方法均支持进度条功能,使用方法与ossClient.putObject类似。

import com.aliyun.oss.ClientException;
import com.aliyun.oss.OSS;
import com.aliyun.oss.common.auth.*;
import com.aliyun.oss.OSSClientBuilder;
import com.aliyun.oss.OSSException;
import com.aliyun.oss.event.ProgressEvent;
import com.aliyun.oss.event.ProgressEventType;
import com.aliyun.oss.event.ProgressListener;
import com.aliyun.oss.model.PutObjectRequest;
import java.io.File;

// 使用进度条,需要实现ProgressListener方法
public class PutObjectProgressListenerDemo implements ProgressListener {
    private long bytesWritten = 0;
    private long totalBytes = -1;
    private boolean succeed = false;

    public static void main(String[] args) throws Exception {
        // Endpoint以华东1(杭州)为例,其它Region请按实际情况填写。
        String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
        // 从环境变量中获取访问凭证。运行本代码示例之前,请确保已设置环境变量OSS_ACCESS_KEY_ID和OSS_ACCESS_KEY_SECRET。
        EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
        // 填写Bucket名称,例如examplebucket。
        String bucketName = "examplebucket";
        // 填写Object完整路径,完整路径中不能包含Bucket名称。例如exampledir/exampleobject.txt。
        String objectName = "exampledir/exampleobject.txt";
        // 填写本地文件的完整路径,例如D:\\localpath\\examplefile.txt。
        String pathName = "D:\\localpath\\examplefile.txt";

        // 创建OSSClient实例。
        OSS ossClient = new OSSClientBuilder().build(endpoint, credentialsProvider);

        try {
            // 上传文件的同时指定进度条参数。此处PutObjectProgressListenerDemo为调用类的类名,请在实际使用时替换为相应的类名。
            ossClient.putObject(new PutObjectRequest(bucketName,objectName, new File(pathName)).
                    <PutObjectRequest>withProgressListener(new PutObjectProgressListenerDemo()));
            // 下载文件的同时指定进度条参数。此处GetObjectProgressListenerDemo为调用类的类名,请在实际使用时替换为相应的类名。
//            ossClient.getObject(new GetObjectRequest(bucketName,objectName).
//                    <GetObjectRequest>withProgressListener(new GetObjectProgressListenerDemo()));

        } catch (OSSException oe) {
            System.out.println("Caught an OSSException, which means your request made it to OSS, "
                    + "but was rejected with an error response for some reason.");
            System.out.println("Error Message:" + oe.getErrorMessage());
            System.out.println("Error Code:" + oe.getErrorCode());
            System.out.println("Request ID:" + oe.getRequestId());
            System.out.println("Host ID:" + oe.getHostId());
        } catch (ClientException ce) {
            System.out.println("Caught an ClientException, which means the client encountered "
                    + "a serious internal problem while trying to communicate with OSS, "
                    + "such as not being able to access the network.");
            System.out.println("Error Message:" + ce.getMessage());
        } finally {
            if (ossClient != null) {
                ossClient.shutdown();
            }
        }
    }

    public boolean isSucceed() {
        return succeed;
    }

    // 使用进度条需要您重写回调方法,以下仅为参考示例。
    @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 upload......");
                break;
            case REQUEST_CONTENT_LENGTH_EVENT:
                this.totalBytes = bytes;
                System.out.println(this.totalBytes + " bytes in total will be uploaded to OSS");
                break;
            case REQUEST_BYTE_TRANSFER_EVENT:
                this.bytesWritten += bytes;
                if (this.totalBytes != -1) {
                    int percent = (int)(this.bytesWritten * 100.0 / this.totalBytes);
                    System.out.println(bytes + " bytes have been written at this time, upload progress: " + percent + "%(" + this.bytesWritten + "/" + this.totalBytes + ")");
                } else {
                    System.out.println(bytes + " bytes have been written at this time, upload ratio: unknown" + "(" + this.bytesWritten + "/...)");
                }
                break;
            case TRANSFER_COMPLETED_EVENT:
                this.succeed = true;
                System.out.println("Succeed to upload, " + this.bytesWritten + " bytes have been transferred in total");
                break;
            case TRANSFER_FAILED_EVENT:
                System.out.println("Failed to upload, " + this.bytesWritten + " bytes have been transferred");
                break;
            default:
                break;
        }
    }
}

相关文档

关于上传文件时进度条使用方法的完整示例代码,请参见GitHub

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