com.databricks.sdk.support

Class Paginator<RQ,RS,T>

java.lang.Object

com.databricks.sdk.support.Paginator<RQ,RS,T>

Type Parameters:

RQ - request type

RS - response type

T - item type

All Implemented Interfaces:

Iterable<T>

public class Paginator<RQ,RS,T>
extends Object
implements Iterable<T>

Consistent pagination support for all APIs

Databricks APIs use two pagination strategies. Token-based APIs may return an empty page that still carries a next_page_token, so iteration must continue until nextPageFn returns null (newTokenPagination(RQ, java.util.function.Function<RQ, RS>, java.util.function.Function<RS, java.util.Collection<T>>, java.util.function.Function<RS, RQ>)). Offset/limit APIs (SCIM, legacy SQL) carry no token and stop on the first empty page (newOffsetPagination(RQ, java.util.function.Function<RQ, RS>, java.util.function.Function<RS, java.util.Collection<T>>, java.util.function.Function<RS, RQ>)).

Constructor Summary

Constructors

Constructor and Description

Paginator(RQ request, Function<RQ,RS> requestFn, Function<RS,Collection<T>> itemsFn, Function<RS,RQ> nextPageFn) Deprecated. Use newTokenPagination(RQ, java.util.function.Function<RQ, RS>, java.util.function.Function<RS, java.util.Collection<T>>, java.util.function.Function<RS, RQ>) or newOffsetPagination(RQ, java.util.function.Function<RQ, RS>, java.util.function.Function<RS, java.util.Collection<T>>, java.util.function.Function<RS, RQ>) instead, which make the pagination strategy explicit. Token-based APIs must use newTokenPagination(RQ, java.util.function.Function<RQ, RS>, java.util.function.Function<RS, java.util.Collection<T>>, java.util.function.Function<RS, RQ>) to avoid stopping early on an empty page that still carries a next-page token.

Method Summary

Modifier and Type	Method and Description
Iterator<T>	iterator()
static <RQ,RS,T> Paginator<RQ,RS,T>	newOffsetPagination(RQ request, Function<RQ,RS> requestFn, Function<RS,Collection<T>> itemsFn, Function<RS,RQ> nextPageFn) Creates a paginator for offset/limit-based APIs, which stop on the first empty page.
static <RQ,RS,T> Paginator<RQ,RS,T>	newTokenPagination(RQ request, Function<RQ,RS> requestFn, Function<RS,Collection<T>> itemsFn, Function<RS,RQ> nextPageFn) Creates a paginator for token-based APIs, which continue past empty pages until nextPageFn returns null.
<ID> Iterable<T>	withDedupe(Function<T,ID> idGetter) De-duplicate results across all pages with an ID This call is only necessary for offset/limit pagination, where additions/removals may get inconsistent results across multiple page calls

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

Paginator

@Deprecated
public Paginator(RQ request,
                             Function<RQ,RS> requestFn,
                             Function<RS,Collection<T>> itemsFn,
                             Function<RS,RQ> nextPageFn)

Deprecated. Use newTokenPagination(RQ, java.util.function.Function<RQ, RS>, java.util.function.Function<RS, java.util.Collection<T>>, java.util.function.Function<RS, RQ>) or newOffsetPagination(RQ, java.util.function.Function<RQ, RS>, java.util.function.Function<RS, java.util.Collection<T>>, java.util.function.Function<RS, RQ>) instead, which make the pagination strategy explicit. Token-based APIs must use newTokenPagination(RQ, java.util.function.Function<RQ, RS>, java.util.function.Function<RS, java.util.Collection<T>>, java.util.function.Function<RS, RQ>) to avoid stopping early on an empty page that still carries a next-page token.

Repeatedly call `requestFn` until `nextPageFn` returns a null result. Uses offset/limit semantics: iteration stops on the first empty page.

Parameters:

request - initial request to `requestFn` implementation, possibly with filters.

requestFn - implementation of request, that takes modified `request` and returns some results.

itemsFn - reference to the getter method, that returns `Collection` of results.

nextPageFn - return non-null request in case we need to fetch another page of results.

Method Detail

newTokenPagination

public static <RQ,RS,T> Paginator<RQ,RS,T> newTokenPagination(RQ request,
                                                              Function<RQ,RS> requestFn,
                                                              Function<RS,Collection<T>> itemsFn,
                                                              Function<RS,RQ> nextPageFn)

Creates a paginator for token-based APIs, which continue past empty pages until nextPageFn returns null.

Example: return Paginator.newTokenPagination(request, impl::list, ListTablesResponse::getTables, response -> { String token = response.getNextPageToken(); if (token == null || token.isEmpty()) { return null; } return request.setPageToken(token); });

Parameters:

request - initial request to `requestFn` implementation, possibly with filters.

requestFn - implementation of request, that takes modified `request` and returns some results.

itemsFn - reference to the getter method, that returns `Collection` of results.

nextPageFn - return non-null request in case we need to fetch another page of results, null once the page token is absent.

newOffsetPagination

public static <RQ,RS,T> Paginator<RQ,RS,T> newOffsetPagination(RQ request,
                                                               Function<RQ,RS> requestFn,
                                                               Function<RS,Collection<T>> itemsFn,
                                                               Function<RS,RQ> nextPageFn)

Creates a paginator for offset/limit-based APIs, which stop on the first empty page.

Example: return Paginator.newOffsetPagination(request, impl::listRuns, ListRunsResponse::getRuns, response -> { Long offset = request.getOffset(); if (offset == null) { offset = 0L; } offset += response.getRuns().size(); return request.setOffset(offset); }).withDedupe(BaseRun::getRunId);

Parameters:

request - initial request to `requestFn` implementation, possibly with filters.

requestFn - implementation of request, that takes modified `request` and returns some results.

itemsFn - reference to the getter method, that returns `Collection` of results.

nextPageFn - return non-null request in case we need to fetch another page of results.

withDedupe

public <ID> Iterable<T> withDedupe(Function<T,ID> idGetter)

De-duplicate results across all pages with an ID

This call is only necessary for offset/limit pagination, where additions/removals may get inconsistent results across multiple page calls

Type Parameters:

ID - ID type, like Long

Parameters:

idGetter - reference to ID getter

Returns:

ID value, like 92384023984

iterator

public Iterator<T> iterator()

Specified by:

iterator in interface Iterable<T>