Package com.tnsai.mcp.server

Interface ResourceProvider

public interface ResourceProvider
Interface for providing resources to an MCP server.

Implement this interface to expose resources (files, data, etc.) to MCP clients. Resources are identified by URIs and can contain text or binary content. Providers may also expose resource templates for parameterized URI patterns.

Example implementation: 


 public class FileResourceProvider implements ResourceProvider {
     private final Path rootDir;

     @Override
     public List<Resource> listResources() {
         return Files.walk(rootDir)
             .filter(Files::isRegularFile)
             .map(path -> Resource.builder()
                 .uri("file://" + path.toString())
                 .name(path.getFileName().toString())
                 .mimeType(Files.probeContentType(path))
                 .build())
             .collect(Collectors.toList());
     }

     @Override
     public List<ResourceTemplate> listResourceTemplates() {
         return List.of(ResourceTemplate.builder()
             .uriTemplate("file:///{path}")
             .name("File by path")
             .description("Access any file by its path")
             .build());
     }

     @Override
     public List<ResourceContent> readResource(String uri) {
         Path path = Paths.get(URI.create(uri));
         String content = Files.readString(path);
         ResourceContent rc = new ResourceContent();
         rc.setUri(uri);
         rc.setText(content);
         rc.setMimeType("text/plain");
         return List.of(rc);
     }
 }

  • Method Details

    • listResources

      List<Resource> listResources()
      Returns the list of resources provided by this provider.
      Returns:
      list of resource definitions

    • listResourceTemplates

      default List<ResourceTemplate> listResourceTemplates()
      Returns the list of resource templates provided by this provider. Templates define parameterized URI patterns that clients can use to construct resource URIs.
      Returns:
      list of resource templates (empty by default)

    • readResource

      List<ResourceContent> readResource(String uri) throws ResourceProvider.ResourceNotFoundException
      Reads the content of a resource.
      Parameters:
      uri - the resource URI
      Returns:
      list of resource contents (may contain multiple parts)
      Throws:
      ResourceProvider.ResourceNotFoundException - if the resource is not found

    • supportsSubscription

      default boolean supportsSubscription()
      Checks if this provider supports resource subscriptions. Override to return true if your provider can notify clients of changes.
      Returns:
      true if subscriptions are supported

    • subscribe

      default void subscribe(String uri, ResourceProvider.ResourceChangeListener listener)
      Subscribes to changes for a resource. Only called if supportsSubscription() returns true.
      Parameters:
      uri - the resource URI
      listener - the listener to notify of changes

    • unsubscribe

      default void unsubscribe(String uri)
      Unsubscribes from changes for a resource.
      Parameters:
      uri - the resource URI