Merge branch 'feature/checker' into development

Author: RillingDev

README.md

@@ -6,7 +6,8 @@
 
 ### Client
 
-The `client` module contains an implementation of a Webmention client which can be used to notify a Webmention endpoint server.
+The `client` module contains an implementation of a Webmention client which can be used to notify a Webmention endpoint
+server.
 
 ```java
 import dev.rilling.webmention4j.client.WebmentionClient;
@@ -38,7 +39,8 @@ public final class WebmentionClientExample {
 
 ### Server
 
-The `server` module contains an implementation of a Webmention endpoint servlet which can be used to listen to Webmentions and process them.
+The `server` module contains an implementation of a Webmention endpoint servlet which can be used to listen to
+Webmentions and process them.
 
 ```java
 import dev.rilling.webmention4j.common.Webmention;
@@ -59,7 +61,8 @@ The `example` module contains example CLI applications that can be executed.
 
 #### Client CLI Example
 
-Webmention client CLI sending Webmention for `http://localhost:8080/somethingelse` being mentioned on `http://localhost:8080/blogpost`:
+Webmention client CLI sending Webmention for `http://localhost:8080/somethingelse` being mentioned
+on `http://localhost:8080/blogpost`:
 
 ```shell
 java -cp webmention4j-example-*.jar dev.rilling.webmention4j.example.WebmentionClientExample --source https://example.com/somethingelse --target https://example.org/blogpost

client/pom.xml

@@ -24,8 +24,8 @@
 			<artifactId>slf4j-api</artifactId>
 		</dependency>
 		<dependency>
-			<groupId>org.jetbrains</groupId>
-			<artifactId>annotations</artifactId>
+			<groupId>org.checkerframework</groupId>
+			<artifactId>checker-qual</artifactId>
 		</dependency>
 
 		<dependency>

client/src/main/java/dev/rilling/webmention4j/client/WebmentionClient.java

@@ -11,7 +11,6 @@
 import org.apache.hc.client5.http.impl.classic.CloseableHttpClient;
 import org.apache.hc.client5.http.impl.classic.HttpClientBuilder;
 import org.apache.hc.client5.http.impl.classic.HttpClients;
-import org.jetbrains.annotations.NotNull;
 
 import java.io.IOException;
 import java.net.URI;
@@ -41,14 +40,14 @@ public WebmentionClient() {
 	 *
 	 * @param config Custom configuration.
 	 */
-	public WebmentionClient(@NotNull Config config) {
+	public WebmentionClient(Config config) {
 		this(new Config(config), WebmentionClient::createDefaultHttpClient, new EndpointService(), new EndpointDiscoveryService(new HeaderLinkParser(), new HtmlLinkParser()));
 	}
 
-	WebmentionClient(@NotNull Config config,
-					 @NotNull HttpClientFactory httpClientFactory,
-					 @NotNull EndpointService endpointService,
-					 @NotNull EndpointDiscoveryService endpointDiscoveryService) {
+	WebmentionClient(Config config,
+					 HttpClientFactory httpClientFactory,
+					 EndpointService endpointService,
+					 EndpointDiscoveryService endpointDiscoveryService) {
 		this.config = config;
 		this.endpointDiscoveryService = endpointDiscoveryService;
 		this.endpointService = endpointService;
@@ -61,7 +60,7 @@ public WebmentionClient(@NotNull Config config) {
 	 * @param target Page to check endpoint of.
 	 * @throws IOException if I/O fails.
 	 */
-	public boolean supportsWebmention(@NotNull URI target) throws IOException {
+	public boolean supportsWebmention(URI target) throws IOException {
 		try (CloseableHttpClient httpClient = httpClientFactory.create(true)) {
 			return endpointDiscoveryService.discoverEndpoint(httpClient, target).isPresent();
 		}
@@ -74,8 +73,8 @@ public boolean supportsWebmention(@NotNull URI target) throws IOException {
 	 * @return URL to use to monitor request status, if supported by the endpoint.
 	 * @throws IOException if I/O fails.
 	 */
-	@NotNull
-	public Optional<URI> sendWebmention(@NotNull Webmention webmention) throws IOException {
+
+	public Optional<URI> sendWebmention(Webmention webmention) throws IOException {
 		URI endpoint;
 		try (CloseableHttpClient httpClient = httpClientFactory.create(true)) {
 			// Spec: '3.1.2 Sender discovers receiver Webmention endpoint'

client/src/main/java/dev/rilling/webmention4j/client/internal/EndpointDiscoveryService.java

@@ -9,7 +9,6 @@
 import org.apache.hc.core5.http.ClassicHttpRequest;
 import org.apache.hc.core5.http.ClassicHttpResponse;
 import org.apache.hc.core5.http.io.support.ClassicRequestBuilder;
-import org.jetbrains.annotations.NotNull;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -23,17 +22,17 @@
 public final class EndpointDiscoveryService {
 	private static final Logger LOGGER = LoggerFactory.getLogger(EndpointDiscoveryService.class);
 
-	private final @NotNull HeaderLinkParser headerLinkParser;
-	private final @NotNull HtmlLinkParser htmlLinkParser;
+	private final HeaderLinkParser headerLinkParser;
+	private final HtmlLinkParser htmlLinkParser;
 
 	/**
 	 * Constructor.
 	 *
 	 * @param headerLinkParser A {@link HeaderLinkParser}.
 	 * @param htmlLinkParser   A {@link HtmlLinkParser}.
 	 */
-	public EndpointDiscoveryService(@NotNull HeaderLinkParser headerLinkParser,
-									@NotNull HtmlLinkParser htmlLinkParser) {
+	public EndpointDiscoveryService(HeaderLinkParser headerLinkParser,
+									HtmlLinkParser htmlLinkParser) {
 		this.headerLinkParser = headerLinkParser;
 		this.htmlLinkParser = htmlLinkParser;
 	}
@@ -49,8 +48,7 @@ public EndpointDiscoveryService(@NotNull HeaderLinkParser headerLinkParser,
 	 * @throws IOException if I/O fails.
 	 */
 	// Spec: https://www.w3.org/TR/webmention/#h-sender-discovers-receiver-webmention-endpoint
-	@NotNull
-	public Optional<URI> discoverEndpoint(@NotNull CloseableHttpClient httpClient, @NotNull URI target)
+	public Optional<URI> discoverEndpoint(CloseableHttpClient httpClient, URI target)
 		throws IOException {
 		// We could make a HEAD request beforehand, but this is not required.
 

client/src/main/java/dev/rilling/webmention4j/client/internal/EndpointService.java

@@ -7,7 +7,6 @@
 import org.apache.hc.core5.http.HttpStatus;
 import org.apache.hc.core5.http.io.support.ClassicRequestBuilder;
 import org.apache.hc.core5.http.message.BasicNameValuePair;
-import org.jetbrains.annotations.NotNull;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -34,10 +33,9 @@ public final class EndpointService {
 	 * @throws IOException if I/O fails.
 	 */
 	// Spec: https://www.w3.org/TR/webmention/#h-sender-notifies-receiver
-	@NotNull
-	public Optional<URI> notifyEndpoint(@NotNull CloseableHttpClient httpClient,
-										@NotNull URI endpoint,
-										@NotNull Webmention webmention) throws IOException {
+	public Optional<URI> notifyEndpoint(CloseableHttpClient httpClient,
+										URI endpoint,
+										Webmention webmention) throws IOException {
 		/*
 		 * Spec:
 		 * 'The sender MUST post x-www-form-urlencoded source and target parameters to the Webmention endpoint,

client/src/main/java/dev/rilling/webmention4j/client/internal/link/HeaderLinkParser.java

@@ -2,7 +2,6 @@
 
 import org.apache.hc.core5.http.ClassicHttpResponse;
 import org.apache.hc.core5.http.HttpHeaders;
-import org.jetbrains.annotations.NotNull;
 
 import java.io.IOException;
 import java.net.URI;
@@ -14,7 +13,7 @@
  */
 public final class HeaderLinkParser implements LinkParser {
 
-	public @NotNull List<Link> parse(@NotNull URI location, @NotNull ClassicHttpResponse response)
+	public List<Link> parse(URI location, ClassicHttpResponse response)
 		throws IOException {
 		try {
 			return Arrays.stream(response.getHeaders(HttpHeaders.LINK))

client/src/main/java/dev/rilling/webmention4j/client/internal/link/HtmlLinkParser.java

@@ -2,7 +2,6 @@
 
 import dev.rilling.webmention4j.common.internal.HtmlUtils;
 import org.apache.hc.core5.http.ClassicHttpResponse;
-import org.jetbrains.annotations.NotNull;
 import org.jsoup.nodes.Document;
 import org.jsoup.nodes.Element;
 import org.jsoup.select.Elements;
@@ -21,7 +20,7 @@ public final class HtmlLinkParser implements LinkParser {
 
 	private static final LinkElementEvaluator LINK_ELEMENT_EVALUATOR = new LinkElementEvaluator();
 
-	public @NotNull List<Link> parse(@NotNull URI location, @NotNull ClassicHttpResponse response)
+	public List<Link> parse(URI location, ClassicHttpResponse response)
 		throws IOException {
 		if (!HtmlUtils.isHtml(response) || response.getEntity() == null) {
 			return List.of();
@@ -48,7 +47,7 @@ private static class LinkElementEvaluator extends Evaluator {
 		private static final Set<String> LINK_ELEMENT_NAMES = Set.of("link", "a");
 
 		@Override
-		public boolean matches(@NotNull Element root, @NotNull Element element) {
+		public boolean matches(Element root, Element element) {
 			return LINK_ELEMENT_NAMES.contains(element.normalName()) && element.hasAttr("href") &&
 				   element.hasAttr("rel");
 		}

client/src/main/java/dev/rilling/webmention4j/client/internal/link/Link.java

@@ -1,7 +1,5 @@
 package dev.rilling.webmention4j.client.internal.link;
 
-import org.jetbrains.annotations.NotNull;
-
 import java.net.URI;
 import java.util.Set;
 
@@ -11,6 +9,6 @@
  * <p>
  * The URL is always in the resolved, absolute form.
  */
-public record Link(@NotNull URI uri, @NotNull Set<String> rel) {
+public record Link(URI uri, Set<String> rel) {
 
 }

client/src/main/java/dev/rilling/webmention4j/client/internal/link/LinkParser.java

@@ -1,7 +1,6 @@
 package dev.rilling.webmention4j.client.internal.link;
 
 import org.apache.hc.core5.http.ClassicHttpResponse;
-import org.jetbrains.annotations.NotNull;
 
 import java.io.IOException;
 import java.net.URI;
@@ -22,6 +21,6 @@ public interface LinkParser {
 	 * @return A list of link elements, ordered by their position in the response.
 	 * @throws IOException if parsing fails.
 	 */
-	@NotNull List<Link> parse(@NotNull URI location, @NotNull ClassicHttpResponse response) throws IOException;
+	List<Link> parse(URI location, ClassicHttpResponse response) throws IOException;
 
 }

client/src/main/java/dev/rilling/webmention4j/client/internal/link/LinkUtils.java

@@ -2,8 +2,7 @@
 
 import org.apache.hc.client5.http.utils.URIUtils;
 import org.apache.hc.core5.net.URIBuilder;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 import java.io.Serial;
 import java.net.URI;
@@ -28,7 +27,7 @@ private LinkUtils() {
 	 * @throws LinkException if parsing fails
 	 */
 	// https://datatracker.ietf.org/doc/html/rfc8288#appendix-A.1
-	public static @NotNull Link fromElement(@NotNull URI baseUri, @NotNull String href, @Nullable String rel) {
+	public static Link fromElement(URI baseUri, String href, @Nullable String rel) {
 		return createLink(baseUri, href, rel);
 	}
 
@@ -41,8 +40,8 @@ private LinkUtils() {
 	 * @throws LinkException if parsing fails
 	 */
 	// https://datatracker.ietf.org/doc/html/rfc8288#section-3
-	public static @NotNull Link fromHeaderValue(
-		@NotNull URI baseUri, @NotNull String headerValue) {
+	public static Link fromHeaderValue(
+		URI baseUri, String headerValue) {
 		String normalizedHeaderValue = headerValue.trim();
 
 		if (!normalizedHeaderValue.startsWith("<")) {
@@ -60,7 +59,7 @@ private LinkUtils() {
 		return createLink(baseUri, uri, rel);
 	}
 
-	private static @Nullable String findRelParam(@NotNull String params) {
+	private static @Nullable String findRelParam(String params) {
 		final StringTokenizer st = new StringTokenizer(params, ";=\"", true);
 		while (st.hasMoreTokens()) {
 			checkToken(st, ";");
@@ -80,7 +79,7 @@ private LinkUtils() {
 		return null;
 	}
 
-	private static void checkToken(@NotNull StringTokenizer st, @NotNull String expected) {
+	private static void checkToken(StringTokenizer st, String expected) {
 		String token;
 		do {
 			token = st.nextToken().trim();
@@ -91,7 +90,7 @@ private static void checkToken(@NotNull StringTokenizer st, @NotNull String expe
 		}
 	}
 
-	private static @NotNull String nextNonEmptyToken(@NotNull StringTokenizer st) {
+	private static String nextNonEmptyToken(StringTokenizer st) {
 		String token;
 		do {
 			token = st.nextToken().trim();
@@ -101,7 +100,7 @@ private static void checkToken(@NotNull StringTokenizer st, @NotNull String expe
 	}
 
 
-	static @NotNull Link createLink(@NotNull URI baseUri, @NotNull String uri, @Nullable String rel) {
+	static Link createLink(URI baseUri, String uri, @Nullable String rel) {
 		Set<String> rels = rel != null ? Set.of(REL_SEPARATOR.split(rel)) : Set.of();
 
 		URI linkUri;
@@ -114,7 +113,7 @@ private static void checkToken(@NotNull StringTokenizer st, @NotNull String expe
 		return new Link(linkUri, rels);
 	}
 
-	private static URI resolveLinkUri(@NotNull URI baseUri, @NotNull String uri) throws URISyntaxException {
+	private static URI resolveLinkUri(URI baseUri, String uri) throws URISyntaxException {
 		URIBuilder uriBuilder = new URIBuilder(uri);
 		if (uriBuilder.isAbsolute()) {
 			return uriBuilder.optimize().build();

client/src/test/java/dev/rilling/webmention4j/client/WebmentionClientSpecIT.java

@@ -27,7 +27,7 @@ class WebmentionClientSpecIT {
 	@Test
 	@DisplayName(
 		"'During the discovery step, if the sender discovers the endpoint is localhost or a loopback IP address (127.0.0.0/8)," +
-			" it SHOULD NOT send the Webmention to that endpoint.'")
+		" it SHOULD NOT send the Webmention to that endpoint.'")
 	void sendWebmentionLocalhost() {
 		Config config = new Config();
 		config.setAllowLocalhostEndpoint(false);
@@ -49,7 +49,7 @@ void sendWebmentionLocalhost() {
 	@Test
 	@DisplayName(
 		"'During the discovery step, if the sender discovers the endpoint is localhost or a loopback IP address (127.0.0.0/8)," +
-			" it SHOULD NOT send the Webmention to that endpoint.'")
+		" it SHOULD NOT send the Webmention to that endpoint.'")
 	void sendWebmentionLocalhostRedirect() {
 		Config config = new Config();
 		config.setAllowLocalhostEndpoint(false);

client/src/test/java/dev/rilling/webmention4j/client/internal/EndpointDiscoveryServiceSpecIT.java

@@ -63,7 +63,7 @@ void usesLinkHeader() throws IOException {
 
 	@Test
 	@DisplayName("'If the content type of the document is HTML, then the sender MUST look for an HTML <link> " +
-		"[...] element with a rel value of webmention' (link element)")
+				 "[...] element with a rel value of webmention' (link element)")
 	void usesLinkHtmlElement() throws IOException {
 		TARGET_SERVER.stubFor(get("/post-by-aaron").willReturn(ok().withHeader(HttpHeaders.CONTENT_TYPE,
 			ContentType.TEXT_HTML.toString()).withBody("""
@@ -84,7 +84,7 @@ void usesLinkHtmlElement() throws IOException {
 
 	@Test
 	@DisplayName("'If the content type of the document is HTML, then the sender MUST look for an HTML [...] <a> " +
-		"element with a rel value of webmention' (anchor element)")
+				 "element with a rel value of webmention' (anchor element)")
 	void usesAnchorHtmlElement() throws IOException {
 		TARGET_SERVER.stubFor(get("/post-by-aaron").willReturn(ok().withHeader(HttpHeaders.CONTENT_TYPE,
 			ContentType.TEXT_HTML.toString()).withBody("""
@@ -131,7 +131,7 @@ void prioritizesHeader() throws IOException {
 
 	@Test
 	@DisplayName("'If more than one of these is present, [...] takes precedence, followed by the first <link> " +
-		"or <a> element in document order'")
+				 "or <a> element in document order'")
 	void prioritizesFirstElement() throws IOException {
 		TARGET_SERVER.stubFor(get("/post-by-aaron").willReturn(ok().withHeader(HttpHeaders.CONTENT_TYPE,
 			ContentType.TEXT_HTML.toString()).withBody("""
@@ -155,7 +155,7 @@ void prioritizesFirstElement() throws IOException {
 
 	@Test
 	@DisplayName("'The endpoint MAY be a relative URL, in which case the sender MUST resolve it relative to the " +
-		"target URL' (header)")
+				 "target URL' (header)")
 	void adaptsRelativeUriForHeader() throws IOException {
 		TARGET_SERVER.stubFor(get("/blog/post-by-aaron").willReturn(ok().withHeader(HttpHeaders.LINK,
 			"<../webmention-endpoint>; rel=\"webmention\"")));
@@ -169,7 +169,7 @@ void adaptsRelativeUriForHeader() throws IOException {
 
 	@Test
 	@DisplayName("'The endpoint MAY be a relative URL, in which case the sender MUST resolve it relative to the " +
-		"target URL' (element)")
+				 "target URL' (element)")
 	void adaptsRelativeUriForElement() throws IOException {
 		TARGET_SERVER.stubFor(get("/blog/post-by-aaron").willReturn(ok().withHeader(HttpHeaders.CONTENT_TYPE,
 			ContentType.TEXT_HTML.toString()).withBody("""
@@ -190,7 +190,7 @@ void adaptsRelativeUriForElement() throws IOException {
 
 	@Test
 	@DisplayName("'The endpoint MAY contain query string parameters, which MUST be preserved as query string " +
-		"parameters' (header)")
+				 "parameters' (header)")
 	void preservesQueryParamsForHeader() throws IOException {
 		TARGET_SERVER.stubFor(get("/post-by-aaron").willReturn(ok().withHeader(HttpHeaders.LINK,
 			"<http://aaronpk.example/webmention-endpoint?version=1>; rel=\"webmention\"")));
@@ -203,7 +203,7 @@ void preservesQueryParamsForHeader() throws IOException {
 
 	@Test
 	@DisplayName("'The endpoint MAY contain query string parameters, which MUST be preserved as query string " +
-		"parameters' (element)")
+				 "parameters' (element)")
 	void preservesQueryParamsForElement() throws IOException {
 		TARGET_SERVER.stubFor(get("/post-by-aaron").willReturn(ok().withHeader(HttpHeaders.CONTENT_TYPE,
 			ContentType.TEXT_HTML.toString()).withBody("""