storage-blob-tags-java.md

title	titleSuffix	description	services	author	ms.author	ms.date	ms.service	ms.topic	ms.devlang	ms.custom
Use blob index tags to manage and find data with Java	Azure Storage	Learn how to categorize, manage, and query for blob objects by using the Java client library.	storage	pauljewellmsft	pauljewell	02/02/2024	azure-blob-storage	how-to	java	devx-track-java, devguide-java, devx-track-extended-java

Use blob index tags to manage and find data with Java

[!INCLUDE storage-dev-guide-selector-index-tags]

This article shows how to use blob index tags to manage and find data using the Azure Storage client library for Java.

Prerequisites

• This article assumes you already have a project set up to work with the Azure Blob Storage client library for Java. To learn about setting up your project, including package installation, adding import directives, and creating an authorized client object, see Get Started with Azure Storage and Java.
• The authorization mechanism must have permissions to work with blob index tags. To learn more, see the authorization guidance for the following REST API operations:
  • Get Blob Tags
  • Set Blob Tags
  • Find Blobs by Tags

[!INCLUDE storage-dev-guide-about-blob-tags]

Set tags

[!INCLUDE storage-dev-guide-auth-set-blob-tags]

You can set tags by using the following method:

• setTags

The specified tags in this method will replace existing tags. If old values must be preserved, they must be downloaded and included in the call to this method. The following example shows how to set tags:

:::code language="java" source="~/azure-storage-snippets/blobs/howto/Java/blob-devguide/blob-devguide-blobs/src/main/java/com/blobs/devguide/blobs/BlobPropertiesMetadataTags.java" id="Snippet_SetBLobTags":::

You can delete all tags by passing an empty Map object into the setTags method:

:::code language="java" source="~/azure-storage-snippets/blobs/howto/Java/blob-devguide/blob-devguide-blobs/src/main/java/com/blobs/devguide/blobs/BlobPropertiesMetadataTags.java" id="Snippet_ClearBLobTags":::

Get tags

[!INCLUDE storage-dev-guide-auth-get-blob-tags]

You can get tags by using the following method:

• getTags

The following example shows how to retrieve and iterate over the blob's tags:

:::code language="java" source="~/azure-storage-snippets/blobs/howto/Java/blob-devguide/blob-devguide-blobs/src/main/java/com/blobs/devguide/blobs/BlobPropertiesMetadataTags.java" id="Snippet_GetBLobTags":::

Filter and find data with blob index tags

[!INCLUDE storage-dev-guide-auth-filter-blob-tags]

Note

You can't use index tags to retrieve previous versions. Tags for previous versions aren't passed to the blob index engine. For more information, see Conditions and known issues.

You can find data by using the following method:

• findBlobsByTags

The following example finds all blobs tagged as an image:

:::code language="java" source="~/azure-storage-snippets/blobs/howto/Java/blob-devguide/blob-devguide-blobs/src/main/java/com/blobs/devguide/blobs/BlobPropertiesMetadataTags.java" id="Snippet_FindBlobsByTag":::

Resources

To learn more about how to use index tags to manage and find data using the Azure Blob Storage client library for Java, see the following resources.

REST API operations

The Azure SDK for Java contains libraries that build on top of the Azure REST API, allowing you to interact with REST API operations through familiar Java paradigms. The client library methods for managing and using blob index tags use the following REST API operations:

• Get Blob Tags (REST API)
• Set Blob Tags (REST API)
• Find Blobs by Tags (REST API)

Code samples

• View code samples from this article (GitHub)

[!INCLUDE storage-dev-guide-resources-java]

See also

• Manage and find Azure Blob data with blob index tags
• Use blob index tags to manage and find data on Azure Blob Storage