Add Spring for Apache Pulsar

Author: onobc

buildSrc/src/main/java/org/springframework/boot/build/classpath/CheckClasspathForProhibitedDependencies.java

@@ -79,6 +79,9 @@ private boolean prohibited(ModuleVersionIdentifier id) {
 		if (group.equals("javax.money")) {
 			return false;
 		}
+		if (group.equals("javax.xml.bind") && id.getName().equals("jaxb-api")) {
+			return false;
+		}
 		if (group.equals("org.codehaus.groovy")) {
 			return true;
 		}

buildSrc/src/main/java/org/springframework/boot/build/context/properties/DocumentConfigurationProperties.java

@@ -169,6 +169,7 @@ private void integrationPrefixes(Config prefix) {
 		prefix.accept("spring.integration");
 		prefix.accept("spring.jms");
 		prefix.accept("spring.kafka");
+		prefix.accept("spring.pulsar");
 		prefix.accept("spring.rabbitmq");
 		prefix.accept("spring.hazelcast");
 		prefix.accept("spring.webservices");

spring-boot-project/spring-boot-autoconfigure/build.gradle

@@ -59,6 +59,11 @@ dependencies {
 	}
 	optional("org.apache.httpcomponents.client5:httpclient5")
 	optional("org.apache.kafka:kafka-streams")
+	optional("org.apache.pulsar:pulsar-client-reactive-producer-cache-caffeine") {
+		// spring-pulsar-reactive includes the pulsar-client-reactive-adapter with
+		// problematic transitive dependencies removed
+		exclude group: "org.apache.pulsar", module: "pulsar-client-reactive-adapter"
+	}
 	optional("org.apache.tomcat.embed:tomcat-embed-core")
 	optional("org.apache.tomcat.embed:tomcat-embed-el")
 	optional("org.apache.tomcat.embed:tomcat-embed-websocket")
@@ -175,6 +180,8 @@ dependencies {
 	optional("org.springframework.data:spring-data-redis")
 	optional("org.springframework.graphql:spring-graphql")
 	optional("org.springframework.hateoas:spring-hateoas")
+	optional("org.springframework.pulsar:spring-pulsar")
+	optional("org.springframework.pulsar:spring-pulsar-reactive")
 	optional("org.springframework.security:spring-security-acl")
 	optional("org.springframework.security:spring-security-config")
 	optional("org.springframework.security:spring-security-data") {
@@ -251,9 +258,9 @@ dependencies {
 	testImplementation("org.testcontainers:junit-jupiter")
 	testImplementation("org.testcontainers:mongodb")
 	testImplementation("org.testcontainers:neo4j")
+	testImplementation("org.testcontainers:pulsar")
 	testImplementation("org.testcontainers:testcontainers")
 	testImplementation("org.yaml:snakeyaml")
-
 	testRuntimeOnly("jakarta.management.j2ee:jakarta.management.j2ee-api")
 	testRuntimeOnly("org.jetbrains.kotlin:kotlin-reflect")
 }

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/pulsar/AuthParameterUtils.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2022-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.autoconfigure.pulsar;
+
+import java.util.Map;
+import java.util.TreeMap;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
+
+import org.apache.pulsar.common.util.ObjectMapperFactory;
+
+import org.springframework.util.CollectionUtils;
+
+/**
+ * Utility methods for Pulsar authentication parameters.
+ *
+ * @author Alexander Preuß
+ */
+final class AuthParameterUtils {
+
+	private static final Pattern KEBAB_CASE_PATTERN = Pattern.compile("-(.)");
+
+	private AuthParameterUtils() {
+
+	}
+
+	private static String convertKebabCaseToCamelCase(String kebabString) {
+		return KEBAB_CASE_PATTERN.matcher(kebabString).replaceAll((mr) -> mr.group(1).toUpperCase());
+	}
+
+	private static Map<String, String> convertWellKnownLowerCaseKeysToCamelCase(Map<String, String> params) {
+		return params.entrySet()
+			.stream()
+			.collect(Collectors.toMap((entry) -> WellKnownAuthParameters.toCamelCaseKey(entry.getKey()),
+					Map.Entry::getValue));
+	}
+
+	private static Map<String, String> convertKebabCaseKeysToCamelCase(Map<String, String> params) {
+		return params.entrySet()
+			.stream()
+			.collect(Collectors.toMap((entry) -> convertKebabCaseToCamelCase(entry.getKey()), Map.Entry::getValue));
+	}
+
+	static String maybeConvertToEncodedParamString(Map<String, String> params) {
+		if (CollectionUtils.isEmpty(params)) {
+			return null;
+		}
+		// env vars are bound like this ISSUER_ID -> issuerid, have to be camel-cased to
+		// work
+		params = convertWellKnownLowerCaseKeysToCamelCase(params);
+		params = convertKebabCaseKeysToCamelCase(params);
+		params = new TreeMap<>(params); // sort keys for testing and readability
+		try {
+			return ObjectMapperFactory.create().writeValueAsString(params);
+		}
+		catch (Exception ex) {
+			throw new RuntimeException("Could not convert parameters to encoded string", ex);
+		}
+	}
+
+}