io.cdap.cdap.api

Interface ServiceDiscoverer

All Known Subinterfaces:

CustomActionContext, HttpServiceContext, MapReduceContext, MapReduceTaskContext<KEYOUT,VALUEOUT>, RuntimeConfigurer, ServiceContext, SparkClientContext, WorkerContext, WorkflowContext

public interface ServiceDiscoverer

An interface for Discovery Service.

Method Summary

Modifier and Type	Method and Description
URL	getServiceURL(String serviceId) Discover the base URL for a Service in the same application, relative to which Service endpoints can be accessed
URL	getServiceURL(String applicationId, String serviceId) Discover the base URL for a Service, relative to which Service endpoints can be accessed
default URL	getServiceURL(String namespaceId, String applicationId, String serviceId) Discover the base URL for a Service of an Application running in a Namespace, relative to which Service endpoints can be accessed
default HttpURLConnection	openConnection(String namespaceId, String applicationId, String serviceId, String methodPath) Opens a HttpURLConnection for connecting to the given Service endpoint.

Method Detail

getServiceURL

@Nullable
default URL getServiceURL(String namespaceId,
                                    String applicationId,
                                    String serviceId)

Discover the base URL for a Service of an Application running in a Namespace, relative to which Service endpoints can be accessed

Parameters:

namespaceId - Namespace of the application

applicationId - Application name

serviceId - Service name

Returns:

URL for the discovered service or null if the service is not found

getServiceURL

@Nullable
URL getServiceURL(String applicationId,
                            String serviceId)

Discover the base URL for a Service, relative to which Service endpoints can be accessed

Parameters:

applicationId - Application name

serviceId - Service name

Returns:

URL for the discovered service or null if the service is not found

getServiceURL

@Nullable
URL getServiceURL(String serviceId)

Discover the base URL for a Service in the same application, relative to which Service endpoints can be accessed

Parameters:

serviceId - Service Name

Returns:

URL for the discovered service or null if the service is not found

openConnection

@Nullable
default HttpURLConnection openConnection(String namespaceId,
                                                   String applicationId,
                                                   String serviceId,
                                                   String methodPath)
                                            throws IOException

Opens a HttpURLConnection for connecting to the given Service endpoint.

Parameters:

namespaceId - Namespace of the application

applicationId - Application name

serviceId - Service name

methodPath - Service method path as declared by the service handler

Returns:

a HttpURLConnection for communicating with the Service endpoint, or null if the service is not found

Throws:

IOException - if Service is found but failed to open a connection to the given Service endpoint