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单链接限速（Java SDK）

最近更新时间：2024.02.04 18:31:06

首次发布时间：2023.08.03 16:36:18

Java SDK 的上传和下载系列接口，包括 getObject、getObjectToFile、putObject等，均支持单链接限速功能。本文介绍如何使用单链接限速功能。

注意事项

从 2.6.0 版本开始，Java SDK 支持服务端对单链接上传下载请求进行限速。

支持单链接限速的 SDK 接口

putObject
putObjectFromFile
appendObject
uploadPart
uploadFile
getObject
getObjectToFile
downloadFile
copyObject
uploadPartCopy
resumableCopyObject

示例代码

以下代码以 getObject 接口为例，展示如何使用客户端限速功能。其他上传下载接口使用方式类似。

import com.volcengine.tos.TOSV2;
import com.volcengine.tos.TOSV2ClientBuilder;
import com.volcengine.tos.TosClientException;
import com.volcengine.tos.TosServerException;
import com.volcengine.tos.model.object.GetObjectV2Input;
import com.volcengine.tos.model.object.GetObjectV2Output;
import com.volcengine.tos.model.object.ObjectMetaRequestOptions;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Map;

public class GetObjectWithTrafficLimitExample {
    public static void main(String[] args) {
        String endpoint = "your endpoint";
        String region = "your region";
        String accessKey = System.getenv("TOS_ACCESS_KEY");
        String secretKey = System.getenv("TOS_SECRET_KEY");

        String bucketName = "bucket-example";
        // 对象名
        String objectKey = "example_dir/example_object.txt";
        // 对象数据保存的本地文件路径，需保证不存在，否则会覆盖原有文件
        String filePath = "example_dir/example_file.txt";

        TOSV2 tos = new TOSV2ClientBuilder().build(region, endpoint, accessKey, secretKey);
        
        // 设置下载限速 5MB/s
        long trafficLimit = 5 * 1024 * 1024;
        ObjectMetaRequestOptions options = new ObjectMetaRequestOptions();
        options.setTrafficLimit(trafficLimit);
        GetObjectV2Input input = new GetObjectV2Input().setBucket(bucketName)
                .setKey(objectKey).setOptions(options);
        File file = new File(filePath);
        if (file.getParentFile() != null && !file.getParentFile().exists()) {
            // 此处判断文件路径的父文件夹是否存在，不存在则创建父文件夹
            // 如果父文件夹不存在且不创建，直接写入会报 FileNotFoundException
            file.getParentFile().mkdirs();
        }
        try(FileOutputStream fos = new FileOutputStream(file);
            GetObjectV2Output output = tos.getObject(input)) {
            if (output.getContent() != null) {
                byte[] buffer = new byte[4096];
                int length;
                while ((length = output.getContent().read(buffer)) != -1) {
                    fos.write(buffer, 0, length);
                }
            }
            fos.flush();
            System.out.println("getObject succeed.");
            System.out.println("object's etag is " + output.getEtag());
            System.out.println("object's lastModified is " + output.getLastModified());
            System.out.println("object's crc64 value is " + output.getHashCrc64ecma());
            System.out.println("object's storageClass is " + output.getStorageClass());
            System.out.println("object's cacheControl is " + output.getCacheControl());
            System.out.println("object's contentDisposition is " + output.getContentDisposition());
            System.out.println("object's contentEncoding is " + output.getContentEncoding());
            System.out.println("object's contentLanguage is " + output.getContentLanguage());
            System.out.println("object's contentType is " + output.getContentType());
            if (output.getCustomMetadata() != null) {
                System.out.println("object has custom meta data.");
                for (Map.Entry<String, String> entry : output.getCustomMetadata().entrySet()) {
                    System.out.println("custom meta key: " + entry.getKey() + ", value: " + entry.getValue());
                }
            }
        } catch (IOException e) {
            System.out.println("write data to file failed");
            e.printStackTrace();
        } catch (TosClientException e) {
            // 操作失败，捕获客户端异常，一般情况是请求参数错误，此时请求并未发送
            System.out.println("getObject failed");
            System.out.println("Message: " + e.getMessage());
            if (e.getCause() != null) {
                e.getCause().printStackTrace();
            }
        } catch (TosServerException e) {
            // 操作失败，捕获服务端异常，可以获取到从服务端返回的详细错误信息
            // 使用限定条件下载，如果服务端返回 304/412 状态码，SDK 将抛出 TosServerException，您需要自行处理。
            System.out.println("getObject failed");
            System.out.println("StatusCode: " + e.getStatusCode());
            System.out.println("Code: " + e.getCode());
            System.out.println("Message: " + e.getMessage());
            System.out.println("RequestID: " + e.getRequestID());
        } catch (Throwable t) {
            // 作为兜底捕获其他异常，一般不会执行到这里
            System.out.println("getObject failed");
            System.out.println("unexpected exception, message: " + t.getMessage());
        }
    }
}

对于 uploadFile、downloadFile 和 resumableCopyObject 3个接口，设置 trafficLimit 限速参数有所不同。
以下代码以 uploadFile 接口为例，展示如何使用单链接限速功能。downloadFile 和 resumableCopyObject 接口使用方式类似。

import com.volcengine.tos.TOSV2;
import com.volcengine.tos.TOSV2ClientBuilder;
import com.volcengine.tos.TosClientException;
import com.volcengine.tos.TosServerException;
import com.volcengine.tos.model.object.UploadFileV2Input;
import com.volcengine.tos.model.object.UploadFileV2Output;

public class UploadFileWithTrafficLimitExample {
    public static void main(String[] args) {
        String endpoint = "your endpoint";
        String region = "your region";
        String accessKey = System.getenv("TOS_ACCESS_KEY");
        String secretKey = System.getenv("TOS_SECRET_KEY");

        String bucketName = "bucket-example";
        // 对象名，模拟 example_dir 下的 example_object.txt 文件
        String objectKey = "example_dir/example_object.txt";
        // uploadFilePath 设置待上传的本地文件路径，建议使用绝对路径，确保文件存在，不支持上传文件夹
        String uploadFilePath = "example_dir/example_file.txt";
        // taskNum 设置并发上传的并发数，范围为 1-1000，默认为 1
        int taskNum = 5;
        // partSize 设置文件分片大小，范围为 5MB-5GB，默认为 20MB
        long partSize = 20 * 1024 * 1024;
        // enableCheckpoint 设置是否开启断点续传功能，开启则会在本地记录上传进度
        boolean enableCheckpoint = true;
        // checkpointFilePath 设置断点续传记录文件存放位置，若不设置则默认在 uploadFilePath 路径下生成
        // 其格式为 {uploadFilePath}.{bucket+objectKey 的 Base64Md5 值}.upload
        String checkpointFilePath = "the checkpoint file path";
        // uploadFile 为并发分片上传，trafficLimit 设置的是每个分片上传的限速值，而非 uploadFile 接口总限速值
        long trafficLimit = 10 * 1024 * 1024;

        TOSV2 tos = new TOSV2ClientBuilder().build(region, endpoint, accessKey, secretKey);

        try {
            UploadFileV2Input input = new UploadFileV2Input().setBucket(bucketName).setKey(objectKey)
                    .setFilePath(uploadFilePath).setEnableCheckpoint(enableCheckpoint)
                    .setCheckpointFile(checkpointFilePath).setPartSize(partSize).setTaskNum(taskNum)
                    .setTrafficLimit(trafficLimit);
            UploadFileV2Output output = tos.uploadFile(input);
            System.out.println("uploadFile succeed, object's etag is " + output.getEtag());
            System.out.println("uploadFile succeed, object's crc64 is " + output.getHashCrc64ecma());
        } catch (TosClientException e) {
            // 操作失败，捕获客户端异常，一般情况是请求参数错误，此时请求并未发送
            System.out.println("uploadFile failed");
            System.out.println("Message: " + e.getMessage());
            if (e.getCause() != null) {
                e.getCause().printStackTrace();
            }
        } catch (TosServerException e) {
            // 操作失败，捕获服务端异常，可以获取到从服务端返回的详细错误信息
            System.out.println("uploadFile failed");
            System.out.println("StatusCode: " + e.getStatusCode());
            System.out.println("Code: " + e.getCode());
            System.out.println("Message: " + e.getMessage());
            System.out.println("RequestID: " + e.getRequestID());
        } catch (Throwable t) {
            // 作为兜底捕获其他异常，一般不会执行到这里
            System.out.println("uploadFile failed");
            System.out.println("unexpected exception, message: " + t.getMessage());
        }
    }
}

注意事项

支持单链接限速的 SDK 接口

示例代码

对象存储

单链接限速（Java SDK）

注意事项

支持单链接限速的 SDK 接口

示例代码