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目录场景（Java SDK）
最近更新时间：2024.02.04 18:31:02首次发布时间：2023.01.19 14:37:15
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TOS 只有对象的概念，内部使用扁平结构存储数据。为方便您对对象进行分组并简化管理，您可以使用目录层次来组织对象。

创建目录

TOS 只有对象的概念，可通过创建一个大小为 0 并且对象名以 / 结尾的对象，模拟目录的功能。
以下代码展示如何在桶 bucket-example 中创建目录 example_dir/ 和子目录 example_dir/aaa/。

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.PutObjectInput;
import com.volcengine.tos.model.object.PutObjectOutput;

public class CreateDirExample {
    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";
        String dir = "example_dir/";
        String dir1 = "example_dir/aaa/";

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

        try{
            PutObjectInput putObjectInput = new PutObjectInput().setBucket(bucketName).setKey(dir).setContent(null);
            PutObjectOutput output = tos.putObject(putObjectInput);
            System.out.println("putObject succeed, object's etag is " + output.getEtag());
            System.out.println("putObject succeed, object's crc64 is " + output.getHashCrc64ecma());

            putObjectInput = new PutObjectInput().setBucket(bucketName).setKey(dir1).setContent(null);
            output = tos.putObject(putObjectInput);
            System.out.println("putObject succeed, object's etag is " + output.getEtag());
            System.out.println("putObject 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("putObject 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("putObject 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("putObject failed");
            System.out.println("unexpected exception, message: " + t.getMessage());
        }
    }
}

模拟目录查询

通过 Delimiter 和 Prefix 两个参数可以模拟目录的功能:

  • 首先设置 Delimiter 为 / 同时设置 Prefix 为空, 可返回根目录下的对象和子目录信息。
  • 在设置 Delimiter 为 / 同时设置 Prefix 为子目录 commonPrefixes, 可返回子目录的对象和次级目录。

以下代码展示如何列举桶 bucket-example 目录 example_dir/ 下的对象和子目录。

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.ListObjectsType2Input;
import com.volcengine.tos.model.object.ListObjectsType2Output;
import com.volcengine.tos.model.object.ListedCommonPrefix;
import com.volcengine.tos.model.object.ListedObjectV2;

public class ListDirExample {
    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";
        int maxKeys = 10;
        String delimiter = "/";
        String prefix = "example_dir/";

        TOSV2 tos = new TOSV2ClientBuilder().build(region, endpoint, accessKey, secretKey);
        try{
            boolean isTruncated = true;
            String continuationToken = null;
            while (isTruncated) {
                ListObjectsType2Input input = new ListObjectsType2Input().setBucket(bucketName).setMaxKeys(maxKeys)
                        .setDelimiter(delimiter).setPrefix(prefix).setContinuationToken(continuationToken);
                ListObjectsType2Output output = tos.listObjectsType2(input);
                System.out.printf("listObjectsType2 succeed, is truncated? %b, next continuation token is %s.\n",
                        output.isTruncated(), output.getNextContinuationToken());
                // 对象
                if (output.getContents() != null) {
                    for (int i = 0; i < output.getContents().size(); i++) {
                        ListedObjectV2 object = output.getContents().get(i);
                        System.out.printf("Listed object, key is %s, size is %d, storageClass is %s, ETag is %s, " +
                                        "last modified is %s, crc64 value is %s.\n", object.getKey(), object.getSize(),
                                object.getStorageClass(), object.getEtag(), object.getLastModified().toString(), object.getHashCrc64ecma());
                    }
                }
                // 子目录
                if (output.getCommonPrefixes() != null) {
                    for (int i = 0; i < output.getCommonPrefixes().size(); i++) {
                        ListedCommonPrefix commonPrefix = output.getCommonPrefixes().get(i);
                        System.out.println("Listed commonPrefix is " + commonPrefix.getPrefix());
                        // commonPrefix 为子目录，可用其作为 prefix 参数继续往下列举
                        listCommonPrefix(bucketName, maxKeys, delimiter, commonPrefix.getPrefix(), tos);
                    }
                }
                isTruncated = output.isTruncated();
                continuationToken = output.getNextContinuationToken();
            }
        } 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("listObjectsType2 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("listObjectsType2 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("listObjectsType2 failed");
            System.out.println("unexpected exception, message: " + t.getMessage());
        }
    }
    
    private static void listCommonPrefix(String bucketName, int maxKeys, String delimiter, String prefix, TOSV2 tos) {
        boolean isTruncated = true;
        String continuationToken = null;
        while (isTruncated) {
            ListObjectsType2Input input = new ListObjectsType2Input().setBucket(bucketName).setMaxKeys(maxKeys)
                    .setDelimiter(delimiter).setContinuationToken(continuationToken).setPrefix(prefix);
            ListObjectsType2Output output = tos.listObjectsType2(input);
            System.out.printf("listObjectsType2 succeed, is truncated? %b, next continuation token is %s.\n",
                    output.isTruncated(), output.getNextContinuationToken());
            if (output.getContents() != null) {
                for (int i = 0; i < output.getContents().size(); i++) {
                    ListedObjectV2 object = output.getContents().get(i);
                    System.out.printf("Listed object, key is %s, size is %d, storageClass is %s, ETag is %s, " +
                                    "last modified is %s, crc64 value is %s.\n", object.getKey(), object.getSize(),
                            object.getStorageClass(), object.getEtag(), object.getLastModified().toString(), object.getHashCrc64ecma());
                }
            }
            if (output.getCommonPrefixes() != null) {
                for (int i = 0; i < output.getCommonPrefixes().size(); i++) {
                    ListedCommonPrefix commonPrefix = output.getCommonPrefixes().get(i);
                    System.out.println("Listed commonPrefix is " + commonPrefix.getPrefix());
                    // 此处可递归调用
                    // listCommonPrefix(bucketName, maxKeys, delimiter, commonPrefix.getPrefix(), tos);
                }
            }
            isTruncated = output.isTruncated();
            continuationToken = output.getNextContinuationToken();
        }
    }
}

删除目录

以下代码展示如何删除桶 bucket-example 目录 example_dir/ 下的所有数据。

警告

以下代码中如果不设置 prefix 参数（即 prefix 为 null）或设置 prefix = "" 空字符串，将会删除桶中所有对象数据，请谨慎检查使用！

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.DeleteObjectInput;
import com.volcengine.tos.model.object.ListObjectsType2Input;
import com.volcengine.tos.model.object.ListObjectsType2Output;

public class DeleteDirExample {
    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";
        String prefix = "example_dir/";

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

        try{
            boolean isTruncated = true;
            String continuationToken = null;
            while (isTruncated) {
                ListObjectsType2Input input = new ListObjectsType2Input().setBucket(bucketName)
                        .setPrefix(prefix).setContinuationToken(continuationToken);
                ListObjectsType2Output output = tos.listObjectsType2(input);
                if (output.getContents() != null){
                    for (int i = 0; i < output.getContents().size(); i++) {
                        String objectKey = output.getContents().get(i).getKey();
                        DeleteObjectInput deleteInput = new DeleteObjectInput().setBucket(bucketName)
                                .setKey(output.getContents().get(i).getKey());
                        tos.deleteObject(deleteInput);
                        System.out.println("deleteObject succeed, deleted key is " + objectKey);
                    }
                }
                isTruncated = output.isTruncated();
                continuationToken = output.getNextContinuationToken();
            }

        } 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("deleteObject 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("deleteObject 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("deleteObject failed");
            System.out.println("unexpected exception, message: " + t.getMessage());
        }
    }
}