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Java单链接限速

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本文介绍如何在上传、下载文件(Object)时,通过在请求中携带限速参数并设置限速值,以保证其他应用的正常带宽。

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

简单上传和下载限速

以下代码用于简单上传和下载文件时设置单链接限速:

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.model.GetObjectRequest;
import com.aliyun.oss.model.PutObjectRequest;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;

public class Demo {
    public static void main(String[] args) throws Throwable {
        // 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";
        // 填写待上传的本地文件的完整路径,例如D:\\localpath\\examplefile.txt。
        // 如果未指定本地路径,则默认从示例程序所属项目对应本地路径中上传文件。
        String localFileName = "D:\\localpath\\examplefile.txt";
        // 填写Object下载到本地文件的完整路径。如果指定的本地文件存在会覆盖,不存在则新建。
        // 如果未指定本地路径,则下载后的文件默认保存到示例程序所属项目对应本地路径中。
        String downLoadFileName = "D:\\localpath\\exampleobject.txt";

        // 限速100 KB/s。
        int limitSpeed = 100 * 1024 * 8;

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

        try {
            // 限速上传。
            InputStream inputStream = new FileInputStream(localFileName);
            PutObjectRequest PutObjectRequest = new PutObjectRequest(bucketName, objectName, inputStream);
            PutObjectRequest.setTrafficLimit(limitSpeed);
            ossClient.putObject(PutObjectRequest);

            // 限速下载。
            GetObjectRequest getObjectRequest = new GetObjectRequest(bucketName, objectName);
            getObjectRequest.setTrafficLimit(limitSpeed);
            File localFile = new File(downLoadFileName);
            ossClient.getObject(getObjectRequest, localFile);
        } 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();
            }
        }
    }
}

分片上传限速

以下代码用于分片上传设置单链接限速:

import com.aliyun.oss.model.*;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

public class DemoApi2 {

    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,例如exampledir/exampleobject.txt。Object完整路径中不能包含Bucket名称。
        String objectName = "exampledir/exampleobject.txt";
        // 限速100 KB/s。
        int limitSpeed = 100 * 1024 * 8;

        // 创建OSSClient实例。
        OSS ossClient = new OSSClientBuilder().build(endpoint, credentialsProvider);
        try {
            // 创建InitiateMultipartUploadRequest对象。
            InitiateMultipartUploadRequest request = new InitiateMultipartUploadRequest(bucketName, objectName);


            // 初始化分片。
            InitiateMultipartUploadResult upresult = ossClient.initiateMultipartUpload(request);
            // 返回uploadId,它是分片上传事件的唯一标识。您可以根据该uploadId发起相关的操作,例如取消分片上传、查询分片上传等。
            String uploadId = upresult.getUploadId();

            // partETags是PartETag的集合。PartETag由分片的ETag和分片号组成。
            List<PartETag> partETags =  new ArrayList<PartETag>();
            // 每个分片的大小,用于计算文件有多少个分片。单位为字节。
            final long partSize = 1 * 1024 * 1024L;   //1 MB。

            // 填写本地文件的完整路径。如果未指定本地路径,则默认从示例程序所属项目对应本地路径中上传文件。
            final File sampleFile = new File("D:\\localpath\\examplefile.txt");
            long fileLength = sampleFile.length();
            int partCount = (int) (fileLength / partSize);
            if (fileLength % partSize != 0) {
                partCount++;
            }
            // 遍历分片上传。
            for (int i = 0; i < partCount; i++) {
                long startPos = i * partSize;
                long curPartSize = (i + 1 == partCount) ? (fileLength - startPos) : partSize;
                InputStream instream = new FileInputStream(sampleFile);
                // 跳过已经上传的分片。
                instream.skip(startPos);
                UploadPartRequest uploadPartRequest = new UploadPartRequest();
                uploadPartRequest.setBucketName(bucketName);
                uploadPartRequest.setKey(objectName);
                uploadPartRequest.setUploadId(uploadId);
                uploadPartRequest.setInputStream(instream);
                // 设置分片大小。除了最后一个分片没有大小限制,其他的分片最小为100 KB。
                uploadPartRequest.setPartSize(curPartSize);
                // 设置分片号。每一个上传的分片都有一个分片号,取值范围是1~10000,如果超出此范围,OSS将返回InvalidArgument错误码。
                uploadPartRequest.setPartNumber( i + 1);
                // 设置限速
                uploadPartRequest.setTrafficLimit(limitSpeed);
                // 每个分片不需要按顺序上传,甚至可以在不同客户端上传,OSS会按照分片号排序组成完整的文件。
                UploadPartResult uploadPartResult = ossClient.uploadPart(uploadPartRequest);
                // 每次上传分片之后,OSS的返回结果包含PartETag。PartETag将被保存在partETags中。
                partETags.add(uploadPartResult.getPartETag());
            }


            // 创建CompleteMultipartUploadRequest对象。
            // 在执行完成分片上传操作时,需要提供所有有效的partETags。OSS收到提交的partETags后,会逐一验证每个分片的有效性。当所有的数据分片验证通过后,OSS将把这些分片组合成一个完整的文件。
            CompleteMultipartUploadRequest completeMultipartUploadRequest =
                    new CompleteMultipartUploadRequest(bucketName, objectName, uploadId, partETags);

            // 完成分片上传。
            CompleteMultipartUploadResult completeMultipartUploadResult = ossClient.completeMultipartUpload(completeMultipartUploadRequest);
            System.out.println(completeMultipartUploadResult.getETag());
        } 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();
            }
        }
    }
}

使用签名URL方式上传和下载限速

以下代码用于使用签名URL方式上传、下载文件时设置单链接限速:

import com.aliyun.oss.*;
import com.aliyun.oss.common.auth.*;
import com.aliyun.oss.model.GeneratePresignedUrlRequest;
import com.aliyun.oss.model.GetObjectRequest;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.net.URL;
import java.util.Date;

public class Demo {
    public static void main(String[] args) throws Throwable {
        // 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";

        // 填写待上传的本地文件的完整路径,例如D:\\localpath\\examplefile.txt。
        // 如果未指定本地路径,则默认从示例程序所属项目对应本地路径中上传文件。
        String localFileName = "D:\\localpath\\examplefile.txt";

        // 填写Object下载到本地文件的完整路径。如果指定的本地文件存在会覆盖,不存在则新建。
        // 如果未指定本地路径,则下载后的文件默认保存到示例程序所属项目对应本地路径中。
        String downLoadFileName = "D:\\localpath\\exampleobject.txt";

        // 限速100 KB/s。
        int limitSpeed = 100 * 1024 * 8;

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

        try {
            // 创建限速上传的URL,有效期60s。
            Date date = new Date();
            date.setTime(date.getTime() + 60 * 1000);
            GeneratePresignedUrlRequest request = new GeneratePresignedUrlRequest(bucketName, objectName, HttpMethod.PUT);
            request.setExpiration(date);
            request.setTrafficLimit(limitSpeed);
            URL signedUrl = ossClient.generatePresignedUrl(request);
            System.out.println("put object url" + signedUrl);

            // 限速上传。
            InputStream inputStream = new FileInputStream(localFileName);
            ossClient.putObject(signedUrl, inputStream, -1, null, true);

            // 创建限速下载的URL,有效期60s。
            date = new Date();
            date.setTime(date.getTime() + 60 * 1000);
            request = new GeneratePresignedUrlRequest(bucketName, objectName, HttpMethod.GET);
            request.setExpiration(date);
            request.setTrafficLimit(limitSpeed);
            signedUrl = ossClient.generatePresignedUrl(request);
            System.out.println("get object url" + signedUrl);

            // 限速下载。
            GetObjectRequest getObjectRequest =  new GetObjectRequest(signedUrl, null);
            ossClient.getObject(getObjectRequest, new File(downLoadFileName));
        } 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();
            }
        }
    }
}

相关文档

关于单链接限速的完整示例代码,请参见GitHub示例

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