NHentai Java Client

This is a Java client providing access to nhentai using nhentai's REST API as well as web scraping. You can use this client to search for galleries (manga, doujinshi etc.), download pages, browse through tags among other things. See API Overview and Usage for more details.

API Overview

API	Operation	Description
Galleries	search	Search for galleries by query
	searchByTag	Search for galleries by tag
	searchByTagId	Search for galleries by tag ID
	getGallery	Get gallery for a specific gallery ID
	getRandomGallery	Get a random gallery
Tags	getTags	Get a list of tags (paginated)
	getAllTags	Get a list of all tags
	getParodies	Get a list of parody tags (paginated)
	getAllParodies	Get a list of all parody tags
	getArtists	Get a list of artist tags (paginated)
	getAllArtists	Get a list of all artist tags
	getCharacters	Get a list of character tags (paginated)
	getAllCharacters	Get a list of all character tags
	getGroups	Get a list of group tags (paginated)
	getAllGroups	Get a list of all group tags

You can also get gallery images, comments etc., but those are part of the Gallery object returned by the Galleries API. See API Usage Examples for reference.

Usage

Initialize NHentai:

var nHentai = new NHentai();

Changing global API options:

You can provide a NHentaiApiConfig when creating the NHentai instance. Currently, the api config contains URLs and some throttling / retry options used by the tags API.

var apiConfig = NHentaiApiConfig.builder().requestDelayMs(200).build();
var nHentai = new NHentai(apiConfig);

API usage Examples

Get gallery by ID:

var gallery = nHentai.galleries().getGallery(177013);

This returns an Optional, because depending on where you got th ID from there might not be any gallery with that ID.

Get and print gallery comments:

for (Comment comment : gallery.getComments()) {
    var userName = comment.getUser().getUserName();
    System.out.printf("[%s] %s: %s%n", comment.getPostDate().toString(), userName, comment.getText());
}

Get and print gallery tags:

var groupedTags = gallery.getTags().stream().collect(Collectors.groupingBy(Tag::getType));

groupedTags.forEach((type, tags)-> {
    var tagString = tags.stream().map(Tag::getName).collect(Collectors.joining(","));
    System.out.printf("%s: %s%n", type.getValue(), tagString);
});

Download gallery pages:

gallery.getPages().forEach(page->{
    var image = page.getImage();
    var file = new File(page.getNumber() + "." + image.getFileExtension());

    try {
        Files.copy(image.toInputStream(), file.toPath(), StandardCopyOption.REPLACE_EXISTING);
    } catch (IOException e) {
        e.printStackTrace();
    }
});

Search for galleries and print pretty title:

var query = "tag:sister language:english -tag:netorare uploaded:<30d";

var result = nHentai.galleries().search(query);
result.getPageResult().forEach(g-> System.out.println(g.getPrettyTitle()));

The query has the same format as a query you would put into the search bar of nhentai. See nhentai documentation for the syntax of these queries. If you don't want to create these queries manually you can use the QueryBuilder. See Create queries with Query Builder for an example using the same query.

Search for galleries with search params:

var query = "tag:sister language:english -tag:netorare uploaded:<30d";
var params = SearchParams.builder().page(2).sortBy(SortBy.RECENT).build();

var result = nHentai.galleries().search(query, params);

Create queries with Query Builder:

var query = Query.builder()
    .withTag("sister")
    .withLanguage(Language.ENGLISH)
    .withoutTag("netorare")
    .uploadedAfter(Duration.ofDays(30))
    .build();

var result = nHentai.galleries().search(query);

Get search results from other pages:

var result = nHentai.galleries().search("artist:Rustle");
var galleries = result.getGalleries();

for (int i = 2; i <= result.getNumberOfPages(); i++) {
    galleries.addAll(result.getGalleriesOnPage(i));
}

Note that the search methods always return paginated results. The getGalleries() method will return the galleries of the page you specified in the search params. If you don't provide a page search param the galleries from page 1 will be returned. Regardless of what page you set in the search params, you can get the galleries for any page of your search result using the getGalleriesOnPage() method.

You can also use this to iterate over all pages to get all galleries of your search result. Be careful when doing this though since there might be a lot of results. The client does not throttle automatically in this case, so this might result in 429 (Too Many Requests) errors.

Get tags

var tags = nHentai.tags().getTags();
tags.forEach(tag-> System.out.println(tag.getName()));

var artistTags = nHentai.tags().getArtists(TagSearchParams.builder().page(3).sortBy(TagSortBy.POPULAR).build());
artistTags.forEach(tag-> System.out.println(tag.getName()));

These methods will return tags for the page you specify in the search params. If you don't specify a page it will default to page 1. If you want to get all tags use Get all tags instead.

Get all tags

var allTheTags = nHentai.tags().getAllTags();
allTheTags.forEach(tag-> System.out.println(tag.getName()));

var allTheArtists = nHentai.tags().getAllArtists();
allTheArtists.forEach(tag-> System.out.println(tag.getName()));

These methods basically iterate through all tag pages and fetch the tags for each page. That means that if there are 50 pages of tags there will be 50 requests to nhentai. All methods of the tag api will automatically throttle themselves for subsequent HTTP calls. If nhentai responds with a HTTP 429 (Too Many Requests) error the client will attempt up to 3 retries after waiting for 500ms. The throttling, max retries and retry delay can also be configured in the NHentaiApiConfig.