extract ConcatenatingIterator, checkerframework changes

src/main/java/io/github/danthe1st/httpsintercept/config/Config.java

@@ -18,8 +18,7 @@
 public record Config(
 		HostMatcherConfig ignoredHosts,
 		List<PreForwardRule> preForwardRules,
-		List<PostForwardRule> postForwardRules
-) {
+		List<PostForwardRule> postForwardRules) {
 
 	public Config(@Nullable HostMatcherConfig ignoredHosts, @Nullable List<PreForwardRule> preForwardRules, @Nullable List<PostForwardRule> postForwardRules) {
 		if(ignoredHosts == null){
@@ -38,7 +37,7 @@ public Config(@Nullable HostMatcherConfig ignoredHosts, @Nullable List<PreForwar
 	}
 
 	public static Config load(Path path) throws IOException {
-		if(!Files.exists(path)) {
+		if(!Files.exists(path)){
 			return new Config(null, null, null);
 		}
 		ObjectMapper mapper = new ObjectMapper(new YAMLFactory());

src/main/java/io/github/danthe1st/httpsintercept/handler/ServerHandlersInit.java

@@ -47,7 +47,7 @@ public ServerHandlersInit(Bootstrap clientBootstrap, Config config) throws KeySt
 		postForwardMatcher = createMatcherFromRules(config.postForwardRules());
 		ignoredHostMatcher = new HostMatcher<>(List.of(Map.entry(config.ignoredHosts(), new Object())), false);
 	}
-
+	
 	private <T extends ProcessingRule> HostMatcher<T> createMatcherFromRules(@UnderInitialization ServerHandlersInit this, List<T> ruleList) {
 		List<Map.Entry<HostMatcherConfig, T>> rules = new ArrayList<>();
 		for(T rule : ruleList){

src/main/java/io/github/danthe1st/httpsintercept/handler/http/HttpResponseContentAccessor.java

@@ -25,7 +25,7 @@ public String getAsString() {
 		ensureBytesPresent();
 		return new String(bytes, StandardCharsets.UTF_8);
 	}
-
+	
 	@EnsuresNonNull("bytes")
 	private void ensureBytesPresent() {
 		if(bytes == null){

src/main/java/io/github/danthe1st/httpsintercept/handler/http/IncomingHttpRequestHandler.java

@@ -85,16 +85,15 @@ private void forwardRequest(ChannelHandlerContext channelHandlerContext, FullHtt
 		}
 	}
 
-
 	// in case Netty caught an exception (e.g. the server is unreachable),
 	// the client receives a 502 Bad Gateway response including the stack trace
 	@Override
 	public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
-			LOG
-				.atError()
-				.addArgument(sniHandler::hostname)
-				.log("An exception occured trying to process a request to host '{}'", cause);
-			ctx.channel().close();
+		LOG
+			.atError()
+			.addArgument(sniHandler::hostname)
+			.log("An exception occured trying to process a request to host '{}'", cause);
+		ctx.channel().close();
 	}
 
 	private void writeException(Throwable cause, Channel channel) throws InterruptedException, IOException {

src/main/java/io/github/danthe1st/httpsintercept/handler/http/ResponseHandler.java

@@ -40,7 +40,7 @@ public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception
 		originalClientContext.channel().close();
 		ctx.channel().close();
 	}
-
+	
 	private void processRules(FullHttpResponse res) {
 		HttpResponseContentAccessor contentAccessor = new HttpResponseContentAccessor(res);
 		for(PostForwardRule rule : postForwardRules){

src/main/java/io/github/danthe1st/httpsintercept/handler/sni/CustomSniHandler.java

@@ -29,7 +29,7 @@ public CustomSniHandler(Mapping<? super String, ? extends SslContext> mapping, B
 		this.clientBootstrapTemplate = clientBootstrapTemplate;
 		ignoredHosts = ignoredHostMatcher;
 	}
-
+	
 	@Override
 	protected void replaceHandler(ChannelHandlerContext channelHandlerContext, String hostname, SslContext sslContext) throws Exception {
 		ChannelPipeline pipeline = channelHandlerContext.pipeline();
@@ -39,7 +39,7 @@ protected void replaceHandler(ChannelHandlerContext channelHandlerContext, Strin
 
 			boolean foundThis = false;
 
-			for(Iterator<Map.Entry<String, ChannelHandler>> it = pipeline.iterator();it.hasNext();) {
+			for(Iterator<Map.Entry<String, ChannelHandler>> it = pipeline.iterator(); it.hasNext();){
 				ChannelHandler handler = it.next().getValue();
 				if(foundThis){
 					it.remove();

src/main/java/io/github/danthe1st/httpsintercept/handler/sni/SNIHandlerMapping.java

@@ -39,7 +39,7 @@ public class SNIHandlerMapping implements Mapping<String, SslContext> {
 	private final Map<String, SslContextCacheEntry> certificateCache = new ConcurrentHashMap<>();
 	private final KeyPair rootKeyPair;
 	private final X509Certificate rootCert;
-
+	
 	private final KeyPair serverKeyPair;
 
 	private SNIHandlerMapping() throws KeyStoreException, IOException, NoSuchAlgorithmException, CertificateException, UnrecoverableKeyException {
@@ -87,7 +87,7 @@ public static SNIHandlerMapping createMapping() throws KeyStoreException, NoSuch
 		Thread.startVirtualThread(mapping::runCleanupDaemon);
 		return mapping;
 	}
-
+	
 	private void runCleanupDaemon() {
 		try{
 			while(true){// NOSONAR ended by potential InterruptedException (or more likely the virtual thread ending)
@@ -101,7 +101,7 @@ private void runCleanupDaemon() {
 			Thread.currentThread().interrupt();
 		}
 	}
-
+	
 	@Override
 	public SslContext map(String hostname) {
 		LOG.debug("loadding certificate for hostname {}", hostname);

src/main/java/io/github/danthe1st/httpsintercept/matcher/ConcatenatingIterator.java

@@ -0,0 +1,29 @@
+package io.github.danthe1st.httpsintercept.matcher;
+
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.Queue;
+
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+final class ConcatenatingIterator<@NonNull T> extends IteratingIterator<T> {
+	private final Queue<Iterator<T>> iterators;
+	private @Nullable Iterator<T> current;
+
+	ConcatenatingIterator(Queue<Iterator<T>> iterators) {
+		this.iterators = iterators;
+		current = iterators.poll();
+	}
+
+	@Override
+	protected Iterator<T> findNextIterator() {
+		while(current != null && !current.hasNext()){
+			current = iterators.poll();
+		}
+		if(current == null){
+			return Collections.emptyIterator();
+		}
+		return current;
+	}
+}

src/main/java/io/github/danthe1st/httpsintercept/matcher/FilterIterator.java

@@ -17,6 +17,7 @@ public FilterIterator(Iterator<@NonNull T> iterator, Predicate<@NonNull T> filte
 		this.iterator = iterator;
 		this.filter = filter;
 	}
+
 	@Override
 	@EnsuresNonNullIf(expression = "current", result = true)
 	public boolean hasNext() {

src/main/java/io/github/danthe1st/httpsintercept/matcher/HostMatcher.java

@@ -16,7 +16,6 @@
 import io.github.danthe1st.httpsintercept.config.HostMatcherConfig;
 import org.checkerframework.checker.initialization.qual.UnderInitialization;
 import org.checkerframework.checker.nullness.qual.NonNull;
-import org.checkerframework.checker.nullness.qual.Nullable;
 
 public final class HostMatcher<@NonNull T> {
 	private final Map<String, List<@NonNull T>> exactHosts;
@@ -48,9 +47,11 @@ public HostMatcher(List<Map.Entry<HostMatcherConfig, @NonNull T>> configs, boole
 
 	private <K> void addToMap(@UnderInitialization HostMatcher<T> this, Map<K, List<@NonNull T>> multimap, @NonNull T value, Set<String> configValue, Function<String, K> keyTransformer) {
 		for(String host : configValue){
-			multimap
-				.computeIfAbsent(keyTransformer.apply(host), h -> new ArrayList<@NonNull T>())
-				.add(value);
+			multimap.merge(
+					keyTransformer.apply(host),
+					new ArrayList<>(),
+					(existing, emptyList) -> existing
+			).add(value);
 		}
 	}
 
@@ -71,24 +72,9 @@ private <K> void addToMap(@UnderInitialization HostMatcher<T> this, Map<K, List<
 		iterators.add(new RegexIterator<>(hostRegexes, hostname));
 		iterators.add(wildcards.iterator());
 
-		Iterator<@NonNull T> it = new IteratingIterator<@NonNull T>() {
-			private @Nullable Iterator<@NonNull T> current = iterators.poll();
-
-			@Override
-			protected Iterator<@NonNull T> findNextIterator() {
-				while(current != null && !current.hasNext()){
-					current = iterators.poll();
-				}
-				if(current == null){
-					return Collections.emptyIterator();
-				}
-				return current;
-			}
-		};
-
-		return distinctIterator(it);
+		return distinctIterator(new ConcatenatingIterator<>(iterators));
 	}
-
+	
 	private Iterator<@NonNull T> distinctIterator(Iterator<@NonNull T> it) {
 		Set<T> matchers = Collections.newSetFromMap(new IdentityHashMap<>());
 		return new FilterIterator<>(it, element -> {

src/main/java/io/github/danthe1st/httpsintercept/matcher/HostPartIterator.java

@@ -36,14 +36,14 @@ protected Iterator<T> findNextIterator() {
 		}while(nextIndex() != -1);
 		return Collections.emptyIterator();
 	}
-
+	
 	private int nextIndex() {
 		index = hostname.indexOf('.', index);
 		if(index != -1){
 			index++;
 		}
 		if(index >= hostname.length()){
-			index=-1;
+			index = -1;
 		}
 		return index;
 	}

src/main/java/io/github/danthe1st/httpsintercept/matcher/IteratingIterator.java

@@ -10,7 +10,7 @@ abstract class IteratingIterator<T> implements Iterator<T> {
 	public boolean hasNext() {
 		return findNextIterator().hasNext();
 	}
-
+	
 	@Override
 	public T next() {
 		return findNextIterator().next();

src/main/java/io/github/danthe1st/httpsintercept/rules/post/HtmlBasedBlocker.java

@@ -33,7 +33,7 @@ public HtmlBasedBlocker(HostMatcherConfig hostMatcher,
 		if(status <= 0){
 			status = 500;
 		}
-		if(responseContentType==null) {
+		if(responseContentType == null){
 			responseContentType = "text/html";
 		}