CRUD Module

Both SolidSyncClient and SolidClient provide methods for reading and writing resources to your Solid Pod; that is, performing create/read/update/delete (CRUD) operations. The resources can be RDF resources as well as non-RDF resources (such as .jpg, .pdf, .txt, .json files).

SolidClient

SolidClient is an asynchronous client for interacting with Solid resources.

SolidClient client = SolidClient.getClient();

For an authenticated client, pass the authenticated Session object to the client:

client.session(mySession);

See also:

• Authentication

• Session Management

.create()

SolidClient.create() creates a new resource (SolidRDFSource, SolidContainer, and SolidNonRDFSource) at the specified location in your Pod.

For example, assume an Expense class that extends SolidRDFSource. To save an Expense object to a Pod, pass the object to the method:

client.create(newExpense).toCompletableFuture().join();

• If any container in the location path does not exist, the method creates the missing containers as well as the resource.

• If the resource already exists at the location, the operation errors with PreconditionFailedException. Use .update() instead.

.read()

SolidClient.read() reads a resource from your Pod and map to a specified class.

For example, assume an Expense class that extends SolidRDFSource. To read the Expense resource from a Pod, pass the resource’s identifier (i.e., its URI) and the class:

Expense myExpense = client.read(
   URI.create("https://..."),
   Expense.class).toCompletableFuture().join();

.update()

SolidClient.update() updates a resource in your Pod.

• If the resource does not exist at the location, creates a new resource.

• If the resource already exists at the location, overwrites the resource.

For example, assume an Expense class that extends SolidRDFSource. To update (or create) an Expense resource in a Pod, pass the object to the method:

// ... Modify the fetched expense
// myExpense.setXXX(...);
// myExpense.setYYY(...);

// Update the RDF resource at the location
// specified in the myExpense's identifier field.

Expense response = client.update(myExpense).toCompletableFuture().join();

.delete()

SolidClient.delete() deletes a resource from your Pod.

• You can specify the URL of the resource to delete:

  client.delete(URI.create("https://...")).toCompletableFuture().join();

or

• You can pass the object to delete:

  For example, assume an Expense class that extends SolidRDFSource.

  client.delete(new Expense(URI.create("https://..."))).toCompletableFuture().join();

To delete a SolidContainer, the SolidContainer must be empty.

SolidSyncClient

SolidSyncClient is a synchronous client for interacting with Solid resources.

SolidSyncClient client = SolidSyncClient.getClient();

For an authenticated client, pass the authenticated Session object to the client:

client.session(mySession);

.create()

SolidSyncClient.create() creates a new resource (SolidRDFSource, SolidContainer, and SolidNonRDFSource) at the specified location in your Pod.

For example, assume an Expense class that extends SolidRDFSource. To save an Expense object to a Pod, pass the object to the method:

client.create(newExpense);

• If any container in the location path does not exist, the method creates the missing containers as well as the resource.

• If the resource already exists at the location, the operation errors with PreconditionFailedException. Use .update() instead.

.read()

SolidSyncClient.read() reads a resource from your Pod and map to a specified class.

or example, assume an Expense class that extends SolidRDFSource. To read the Expense resource from a Pod, pass the resource’s identifier (i.e., its URI) and the class:

Expense myExpense = client.read(
   URI.create("https://..."),
   Expense.class);

.update()

SolidSyncClient.update() updates a resource in your Pod.

• If the resource does not exist at the location, it creates a new resource.

• If the resource already exists at the location, it overwrites the resource.

For example, assume a Expense class that extends SolidRDFSource. To update (or create) an Expense resource in a Pod, pass the object to the method:

// ... Modify the fetched expense
// myExpense.setXXX(...);
// myExpense.setYYY(...);

// Update the RDF resource at the location
// specified in the myExpense's identifier field.

Expense response = client.update(myExpense);

.delete()

SolidSyncClient.delete() deletes a resource from your Pod.

• You can specify the URL of the resource to delete:

  client.delete(URI.create("https://..."));

or

• You can specify the object to delete:

  For example, assume a Expense class that extends SolidRDFSource.

  client.delete(new Expense(URI.create("https://...")));

To delete a SolidContainer, the SolidContainer must be empty.

Headers

You can use the resource class’ getHeaders() method to get the headers:

• SolidRDFSource.getHeaders()

• SolidContainer.getHeaders()

• SolidNonRDFSource.getHeaders()

See also Headers.

Alternatively, you can also use the resource class’ getMetadata() methods:

• SolidRDFSource.getMetadata()

• SolidContainer.getMetadata()

• SolidNonRDFSource.getMetadata()

The getMetadata() methods return Solid-specific data (parsed into Java types) from a resource’s response headers. To access the complete set of response headers, use the getHeaders() method.