Pod Resources#

Solid Pods are data storage locations. Pods can store different types of resources:

Resource Description Framework (RDF) Resource#

RDF resource is a document/file whose contents consists of statements that have the following form (also known as a triple):

<subject> <predicate> <object>

where:

  • subject is the thing being described and is a URI.

  • predicate is the descriptive property (e.g., name, height, size, etc.) of the thing and is a URI.

  • object is the property value and is either a URI or a literal.

The predicate describes the relationship between the subject and the object.

SolidRDFSource#

The SolidRDFSource class maps to an RDF resource stored or to be stored in a Solid Pod. [1]

A summary of parameters to the SolidRDFSource class constructors are as follows:

Field

Type

Description

identifier

java.net.URI

The URI (Uniform Resource Identifier) of the resource.

dataset

org.apache.commons.rdf.api.Dataset

The RDF dataset (i.e., the set(s) of triples) contained in the resource.

headers

com.inrupt.client.Headers

Collection of HTTP headers.

To instantiate, specify the identifier (i.e., the URI) for the resource:

// Locally instantiate a new resource
SolidRDFSource newResource = new SolidRDFSource(
      URI.create("https://pod.example.com/resource/path"));  // identifier

Optionally, you can also initialize the resource data during instantiation by including an RDF dataset:

// Locally instantiate a new resource with initial RDF Dataset
SolidRDFSource newResourcePopulated = new SolidRDFSource(
      URI.create("https://pod.example.com/resource/path"),  // identifier
      initialDataset);                                                  // dataset

You can extended the SolidRDFSource class to model a POJO (Plain Old Java Object) class as an RDF resources. See Data Modeling (RDF) and Modeling an RDF Resource for information on modeling POJOs as RDF resources.

Class Methods#

You can:

Read/Write to Pod#

To read RDF resources from your Pod or write RDF resources to your Pod (i.e., CRUD operations), the library provides SolidSyncClient and SolidClient classes. See CRUD for details.

Tip

When saving a new resource to a Pod (e.g., https://pod.example.com/container1/container2/resource), if any Container in the resource path does not exist (e.g., container1/ and container2/), the SolidSyncClient.create() and SolidClient.create() methods creates the missing containers as well.

For the CRUD operation response headers, you can use SolidRDFSource.getHeaders(). See Appendix: Headers.

Container#

A Container is an RDF resource that can contain other RDF (including other Containers) and non-RDF resources. A Container is analogous to a folder in a file system.

Important

Container URIs always end with a slash /.

SolidContainer#

The SolidContainer class maps to a Container stored or to be stored in a Solid Pod. [1] The SolidContainer class extends SolidRDFSource.

To instantiate, specify the destination URI for the Container. Container URIs always end with a slash /.

// Locally instantiate a new Container.
// Container URIs ends with a slash "/"
SolidContainer newResource = new SolidContainer(
      URI.create("https://pod.example.com/container/path/"));

Class Methods#

You can use SolidContainer class methods to interact with a Container directly. For example, to retrieve all contained resources within a Container, you can use getResources.

Read/Write to Pod#

To read Containers from your Pod or write Containers to your Pod (i.e., CRUD operations), the library provides SolidSyncClient and SolidClient classes.

Tip

  • Although you can instantiate and save a SolidContainer by itself, when creating a resource to a Pod (e.g., https://pod.example.com/container1/container2/resource), if any Container in the location path does not exist (e.g., container1/ and container2/), the SolidSyncClient.create() and SolidClient.create() methods creates the missing containers as well as the resource.

  • To delete a Container, the Container must be empty.

For the CRUD operation response headers, you can use SolidContainer.getHeaders(). See Appendix: Headers.

Non-RDF Resource#

A non-RDF Resource is any non-RDF binary or text file, such as .pdf, .jpeg, etc.

SolidNonRDFSource#

The SolidNonRDFSource class maps to a non-RDF resources stored or to be stored in a Solid Pod. [1]

A summary of parameters to the SolidNonRDFSource class constructors are as follows:

Field

Type

Description

identifier

java.net.URI

The URI (Uniform Resource Identifier) of the resource.

contentType

java.lang.String

The MIME type for the file.

entity

java.io.InputStream

Input stream of the file content.

To instantiate, specify the identifier (i.e., the URI), the content type (i.e., MIME type), and the input stream for the resource. For example, the following instantiates a SolidNonRDFSource for a .jpg file:

MultipartFile file = //... Some .jpg file

// Locally instantiate a new SolidNonRDFSource.
SolidNonRDFSource newNonRDFSource = new SolidNonRDFSource(
   URI.create("https://pod.example.com/container1/somePic.jpg"),  // identifier
   file.getContentType(),                 // MIME type
   file.getInputStream());                // InputStream

Read/Write to Pod#

To read non-RDF resources from your Pod or write non-RDF resources to your Pod (i.e., CRUD operations), the library provides SolidSyncClient and SolidClient classes. See CRUD for details.

Tip

When saving a new resource to a Pod (e.g., https://pod.example.com/container1/container2/somePic.jpg), if any Container in the resource path does not exist (e.g., container1/ and container2/), the SolidSyncClient.create() and SolidClient.create() methods creates the missing containers as well.

For the CRUD operation response headers, you can use SolidNonRDFSource.getHeaders(). See Appendix: Headers.

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