Support for new Spring Boot ConfigData framework. (#265)

spring-cloud-zookeeper-config/src/main/java/org/springframework/cloud/zookeeper/config/ZookeeperConfigAutoConfiguration.java

@@ -16,14 +16,20 @@
 
 package org.springframework.cloud.zookeeper.config;
 
+import java.util.Collections;
+import java.util.List;
+
 import org.apache.curator.framework.CuratorFramework;
 
+import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.cloud.endpoint.RefreshEndpoint;
 import org.springframework.cloud.zookeeper.ConditionalOnZookeeperEnabled;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.core.env.Environment;
 
 /**
  * {@link org.springframework.boot.autoconfigure.EnableAutoConfiguration
@@ -39,15 +45,24 @@ public class ZookeeperConfigAutoConfiguration {
 
 	@Configuration(proxyBeanMethods = false)
 	@ConditionalOnClass(RefreshEndpoint.class)
+	@ConditionalOnProperty(name = "spring.cloud.zookeeper.config.watcher.enabled", matchIfMissing = true)
 	protected static class ZkRefreshConfiguration {
 
 		@Bean
-		@ConditionalOnProperty(name = "spring.cloud.zookeeper.config.watcher.enabled", matchIfMissing = true)
-		public ConfigWatcher configWatcher(ZookeeperPropertySourceLocator locator,
+		@ConditionalOnBean(ZookeeperPropertySourceLocator.class)
+		public ConfigWatcher propertySourceLocatorConfigWatcher(ZookeeperPropertySourceLocator locator,
 				CuratorFramework curator) {
 			return new ConfigWatcher(locator.getContexts(), curator);
 		}
 
+		@Bean
+		@ConditionalOnMissingBean(ZookeeperPropertySourceLocator.class)
+		public ConfigWatcher configDataConfigWatcher(CuratorFramework curator, Environment env) {
+			List<String> contexts = env.getProperty("spring.cloud.zookeeper.config.property-source-contexts",
+					List.class, Collections.emptyList());
+			return new ConfigWatcher(contexts, curator);
+		}
+
 	}
 
 }

spring-cloud-zookeeper-config/src/main/java/org/springframework/cloud/zookeeper/config/ZookeeperConfigDataLoader.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright 2015-2020 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.cloud.zookeeper.config;
+
+import java.util.Collections;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+import org.springframework.boot.context.config.ConfigData;
+import org.springframework.boot.context.config.ConfigDataLoader;
+import org.springframework.boot.context.config.ConfigDataLoaderContext;
+import org.springframework.boot.context.config.ConfigDataLocationNotFoundException;
+
+public class ZookeeperConfigDataLoader implements ConfigDataLoader<ZookeeperConfigDataLocation> {
+
+	private static final Log log = LogFactory.getLog(ZookeeperPropertySourceLocator.class);
+
+	@Override
+	public ConfigData load(ConfigDataLoaderContext context, ZookeeperConfigDataLocation location) {
+		try {
+			ZookeeperPropertySource propertySource = new ZookeeperPropertySource(location.getContext(),
+					location.getCurator());
+			return new ConfigData(Collections.singletonList(propertySource));
+		}
+		catch (Exception e) {
+			if (location.getProperties().isFailFast() || !location.isOptional()) {
+				throw new ConfigDataLocationNotFoundException(location, e);
+			}
+			else {
+				log.warn("Unable to load zookeeper config from " + location.getContext(), e);
+			}
+		}
+		return null;
+	}
+
+}

spring-cloud-zookeeper-config/src/main/java/org/springframework/cloud/zookeeper/config/ZookeeperConfigDataLocation.java

@@ -0,0 +1,85 @@
+/*
+ * Copyright 2015-2020 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.cloud.zookeeper.config;
+
+import java.util.Objects;
+
+import org.apache.curator.framework.CuratorFramework;
+
+import org.springframework.boot.context.config.ConfigDataLocation;
+import org.springframework.core.style.ToStringCreator;
+
+public class ZookeeperConfigDataLocation extends ConfigDataLocation {
+
+	private final CuratorFramework curator;
+	private final ZookeeperConfigProperties properties;
+	private final String context;
+	private final boolean optional;
+
+	public ZookeeperConfigDataLocation(CuratorFramework curator, ZookeeperConfigProperties properties, String context, boolean optional) {
+		this.curator = curator;
+		this.properties = properties;
+		this.context = context;
+		this.optional = optional;
+	}
+
+	public CuratorFramework getCurator() {
+		return this.curator;
+	}
+
+	public ZookeeperConfigProperties getProperties() {
+		return this.properties;
+	}
+
+	public String getContext() {
+		return this.context;
+	}
+
+	public boolean isOptional() {
+		return this.optional;
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		if (this == o) {
+			return true;
+		}
+		if (o == null || getClass() != o.getClass()) {
+			return false;
+		}
+		ZookeeperConfigDataLocation that = (ZookeeperConfigDataLocation) o;
+		return this.curator.equals(that.curator) &&
+				this.properties.equals(that.properties) &&
+				this.optional == that.optional &&
+				this.context.equals(that.context);
+	}
+
+	@Override
+	public int hashCode() {
+		return Objects.hash(this.curator, this.properties, this.context);
+	}
+
+	@Override
+	public String toString() {
+		return new ToStringCreator(this)
+				.append("context", context)
+				.append("optional", optional)
+				.append("properties", properties)
+				.toString();
+
+	}
+}

spring-cloud-zookeeper-config/src/main/java/org/springframework/cloud/zookeeper/config/ZookeeperConfigDataLocationResolver.java

@@ -0,0 +1,159 @@
+/*
+ * Copyright 2015-2020 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.cloud.zookeeper.config;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.curator.RetryPolicy;
+import org.apache.curator.framework.CuratorFramework;
+import org.apache.curator.framework.CuratorFrameworkFactory;
+import org.apache.curator.retry.ExponentialBackoffRetry;
+
+import org.springframework.boot.context.config.ConfigDataLocationNotFoundException;
+import org.springframework.boot.context.config.ConfigDataLocationResolver;
+import org.springframework.boot.context.config.ConfigDataLocationResolverContext;
+import org.springframework.boot.context.config.Profiles;
+import org.springframework.boot.context.properties.bind.Bindable;
+import org.springframework.boot.context.properties.bind.Binder;
+import org.springframework.cloud.zookeeper.ZookeeperAutoConfiguration;
+import org.springframework.cloud.zookeeper.ZookeeperProperties;
+import org.springframework.core.env.MapPropertySource;
+
+public class ZookeeperConfigDataLocationResolver implements ConfigDataLocationResolver<ZookeeperConfigDataLocation> {
+
+	private static final Log log = LogFactory.getLog(ZookeeperAutoConfiguration.class);
+
+	@Override
+	public boolean isResolvable(ConfigDataLocationResolverContext context, String location) {
+		boolean zkEnabled = context.getBinder().bind(ZookeeperProperties.PREFIX + ".enabled", Boolean.class)
+				.orElse(true);
+		boolean zkConfigEnabled = context.getBinder().bind(ZookeeperConfigProperties.PREFIX + ".enabled", Boolean.class)
+				.orElse(true);
+		return location.startsWith("zookeeper:") && zkConfigEnabled && zkEnabled;
+	}
+
+	@Override
+	public List<ZookeeperConfigDataLocation> resolve(ConfigDataLocationResolverContext context, String location, boolean optional) throws ConfigDataLocationNotFoundException {
+		return Collections.emptyList();
+	}
+
+	@Override
+	public List<ZookeeperConfigDataLocation> resolveProfileSpecific(ConfigDataLocationResolverContext context, String location, boolean optional, Profiles profiles) throws ConfigDataLocationNotFoundException {
+		// TODO use location for host:port
+		CuratorFramework curator = curatorFramework(optional, loadProperties(context.getBinder()));
+
+		String appName = context.getBinder().bind("spring.application.name", String.class).orElse("application");
+
+		ZookeeperConfigProperties properties = loadConfigProperties(context.getBinder());
+		String root = properties.getRoot();
+		List<String> contexts = new ArrayList<>();
+
+		String defaultContext = root + "/" + properties.getDefaultContext();
+		contexts.add(defaultContext);
+		addProfiles(contexts, defaultContext, profiles, properties);
+
+		StringBuilder baseContext = new StringBuilder(root);
+		if (!appName.startsWith("/")) {
+			baseContext.append("/");
+		}
+		baseContext.append(appName);
+		contexts.add(baseContext.toString());
+		addProfiles(contexts, baseContext.toString(), profiles, properties);
+
+		Collections.reverse(contexts);
+
+		context.getBootstrapRegistry().register(CuratorFramework.class, () -> curator)
+				.onApplicationContextPrepared((ctxt, curatorFramework) -> {
+					ctxt.getBeanFactory().registerSingleton("configDataCuratorFramework", curatorFramework);
+					HashMap<String, Object> source = new HashMap<>();
+					source.put("spring.cloud.zookeeper.config.property-source-contexts", contexts);
+					MapPropertySource propertySource = new MapPropertySource("zookeeperConfigData", source);
+					ctxt.getEnvironment().getPropertySources().addFirst(propertySource);
+				});
+
+		ArrayList<ZookeeperConfigDataLocation> locations = new ArrayList<>();
+		contexts.forEach(propertySourceContext -> locations
+				.add(new ZookeeperConfigDataLocation(curator, properties, propertySourceContext, optional)));
+
+		return locations;
+	}
+
+	private void addProfiles(List<String> contexts, String baseContext, Profiles profiles,
+			ZookeeperConfigProperties properties) {
+		for (String profile : profiles.getAccepted()) {
+			contexts.add(baseContext + properties.getProfileSeparator() + profile);
+		}
+	}
+
+	protected CuratorFramework curatorFramework(boolean optional, ZookeeperProperties properties) {
+		CuratorFrameworkFactory.Builder builder = CuratorFrameworkFactory.builder();
+
+		builder.connectString(properties.getConnectString())
+				.sessionTimeoutMs((int) properties.getSessionTimeout().toMillis())
+				.connectionTimeoutMs((int) properties.getConnectionTimeout().toMillis())
+				.retryPolicy(retryPolicy(properties));
+
+		CuratorFramework curator = builder.build();
+
+		curator.start();
+		if (log.isTraceEnabled()) {
+			log.trace("blocking until connected to zookeeper for " + properties.getBlockUntilConnectedWait()
+					+ properties.getBlockUntilConnectedUnit());
+		}
+		try {
+			curator.blockUntilConnected(properties.getBlockUntilConnectedWait(),
+					properties.getBlockUntilConnectedUnit());
+		}
+		catch (InterruptedException e) {
+			if (!optional) {
+				log.error("Unable to connect to zookeeper", e);
+				throw new ConfigDataLocationNotFoundException("Unable to connect to zookeeper", null, e);
+			}
+			else if (log.isDebugEnabled()) {
+				log.debug("Unable to connect to zookeeper", e);
+			}
+		}
+		if (log.isTraceEnabled()) {
+			log.trace("connected to zookeeper");
+		}
+		return curator;
+	}
+
+	protected RetryPolicy retryPolicy(ZookeeperProperties properties) {
+		return new ExponentialBackoffRetry(properties.getBaseSleepTimeMs(), properties.getMaxRetries(),
+				properties.getMaxSleepMs());
+	}
+
+	protected ZookeeperProperties loadProperties(Binder binder) {
+		ZookeeperProperties properties = binder.bind(ZookeeperProperties.PREFIX, Bindable.of(ZookeeperProperties.class))
+				.orElse(new ZookeeperProperties());
+		return properties;
+	}
+
+	protected ZookeeperConfigProperties loadConfigProperties(Binder binder) {
+		ZookeeperConfigProperties properties = binder
+				.bind(ZookeeperConfigProperties.PREFIX, Bindable.of(ZookeeperConfigProperties.class))
+				.orElse(new ZookeeperConfigProperties());
+		return properties;
+	}
+
+}

spring-cloud-zookeeper-config/src/main/java/org/springframework/cloud/zookeeper/config/ZookeeperConfigProperties.java

@@ -26,9 +26,14 @@ import org.springframework.util.Assert;
  * @since 1.0.0
  * @see ZookeeperPropertySourceLocator
  */
-@ConfigurationProperties("spring.cloud.zookeeper.config")
+@ConfigurationProperties(ZookeeperConfigProperties.PREFIX)
 public class ZookeeperConfigProperties {
 
+	/**
+	 * Configuration prefix for config properties.
+	 */
+	public static final String PREFIX = "spring.cloud.zookeeper.config";
+
 	private boolean enabled = true;
 
 	/**

spring-cloud-zookeeper-config/src/main/resources/META-INF/spring.factories

@@ -5,3 +5,11 @@ org.springframework.cloud.zookeeper.config.ZookeeperConfigAutoConfiguration
 # Bootstrap Configuration
 org.springframework.cloud.bootstrap.BootstrapConfiguration=\
 org.springframework.cloud.zookeeper.config.ZookeeperConfigBootstrapConfiguration
+
+# ConfigData Location Resolvers
+org.springframework.boot.context.config.ConfigDataLocationResolver=\
+org.springframework.cloud.zookeeper.config.ZookeeperConfigDataLocationResolver
+
+# ConfigData Loaders
+org.springframework.boot.context.config.ConfigDataLoader=\
+org.springframework.cloud.zookeeper.config.ZookeeperConfigDataLoader

spring-cloud-zookeeper-config/src/test/java/org/springframework/cloud/zookeeper/config/ZookeeperConfigAutoConfigurationTests.java

@@ -16,8 +16,8 @@
 
 package org.springframework.cloud.zookeeper.config;
 
-import java.net.ConnectException;
-
+import org.apache.zookeeper.KeeperException;
+import org.hamcrest.Matchers;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Rule;
@@ -25,8 +25,9 @@ import org.junit.Test;
 import org.junit.rules.ExpectedException;
 
 import org.springframework.beans.factory.NoSuchBeanDefinitionException;
+import org.springframework.boot.SpringBootConfiguration;
 import org.springframework.boot.WebApplicationType;
-import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.builder.SpringApplicationBuilder;
 import org.springframework.context.ConfigurableApplicationContext;
 
@@ -72,7 +73,7 @@ public class ZookeeperConfigAutoConfigurationTests {
 	@Test
 	public void testConfigEnabledTrueLoadsZookeeperConfigAutoConfiguration()
 			throws Exception {
-		expectedException.expect(ConnectException.class);
+		expectedException.expectCause(Matchers.isA(KeeperException.class));
 
 		new SpringApplicationBuilder().sources(Config.class).web(WebApplicationType.NONE)
 				.run("--spring.application.name=testZookeeperConfigEnabledSetToTrue",
@@ -87,7 +88,8 @@ public class ZookeeperConfigAutoConfigurationTests {
 						"--spring.cloud.zookeeper.config.enabled=true");
 	}
 
-	@SpringBootApplication
+	@SpringBootConfiguration
+	@EnableAutoConfiguration
 	static class Config {
 
 	}

spring-cloud-zookeeper-config/src/test/java/org/springframework/cloud/zookeeper/config/ZookeeperConfigDataIntegrationTests.java

@@ -0,0 +1,215 @@
+/*
+ * Copyright 2015-2019 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.cloud.zookeeper.config;
+
+import java.util.List;
+import java.util.UUID;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.curator.framework.CuratorFramework;
+import org.apache.curator.framework.CuratorFrameworkFactory;
+import org.apache.curator.retry.RetryOneTime;
+import org.apache.curator.test.TestingServer;
+import org.apache.zookeeper.KeeperException;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import org.springframework.boot.WebApplicationType;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.builder.SpringApplicationBuilder;
+import org.springframework.cloud.context.environment.EnvironmentChangeEvent;
+import org.springframework.cloud.context.refresh.ConfigDataContextRefresher;
+import org.springframework.cloud.context.refresh.ContextRefresher;
+import org.springframework.cloud.context.scope.refresh.RefreshScope;
+import org.springframework.context.ApplicationListener;
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.env.ConfigurableEnvironment;
+import org.springframework.util.SocketUtils;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * @author Spencer Gibb
+ */
+public class ZookeeperConfigDataIntegrationTests {
+
+	private static final Log log = LogFactory
+			.getLog(ZookeeperConfigDataIntegrationTests.class);
+
+	public static final String PREFIX = "test__configdata__";
+
+	public static final String ROOT = "/" + PREFIX + UUID.randomUUID();
+
+	public static final String CONTEXT = ROOT + "/application/";
+
+	public static final String KEY_BASIC = "testProp";
+
+	public static final String KEY_BASIC_PATH = CONTEXT + KEY_BASIC;
+
+	public static final String VAL_BASIC = "testPropVal";
+
+	public static final String KEY_WITH_DOT = "testProp.dot";
+
+	public static final String KEY_WITH_DOT_PATH = CONTEXT + KEY_WITH_DOT;
+
+	public static final String VAL_WITH_DOT = "withDotVal";
+
+	public static final String KEY_NESTED = "testProp.nested";
+
+	public static final String KEY_NESTED_PATH = CONTEXT + KEY_NESTED.replace('.', '/');
+
+	public static final String VAL_NESTED = "nestedVal";
+
+	public static final String KEY_WITHOUT_VALUE = "testProp.novalue";
+
+	public static final String KEY_WITHOUT_VALUE_PATH = CONTEXT + KEY_WITHOUT_VALUE;
+
+	private ConfigurableEnvironment environment;
+
+	private ConfigurableApplicationContext context;
+
+	private TestingServer testingServer;
+
+	private CuratorFramework curator;
+
+	@Before
+	public void setup() throws Exception {
+		int port = SocketUtils.findAvailableTcpPort();
+		this.testingServer = new TestingServer(port);
+		String connectString = "localhost:" + port;
+		this.curator = CuratorFrameworkFactory.builder()
+				.retryPolicy(new RetryOneTime(500)).connectString(connectString).build();
+		this.curator.start();
+
+		List<String> children = this.curator.getChildren().forPath("/");
+		for (String child : children) {
+			if (child.startsWith(PREFIX) && child.length() > PREFIX.length()) {
+				delete("/" + child);
+			}
+		}
+
+		StringBuilder create = new StringBuilder(1024);
+		create.append(this.curator.create().creatingParentsIfNeeded()
+				.forPath(KEY_BASIC_PATH, VAL_BASIC.getBytes())).append('\n');
+		create.append(this.curator.create().creatingParentsIfNeeded()
+				.forPath(KEY_WITH_DOT_PATH, VAL_WITH_DOT.getBytes())).append('\n');
+		create.append(this.curator.create().creatingParentsIfNeeded()
+				.forPath(KEY_NESTED_PATH, VAL_NESTED.getBytes())).append('\n');
+		create.append(this.curator.create().creatingParentsIfNeeded()
+				.forPath(KEY_WITHOUT_VALUE_PATH, null)).append('\n');
+		this.curator.close();
+		System.out.println(create);
+
+		this.context = new SpringApplicationBuilder(Config.class)
+				.web(WebApplicationType.NONE)
+				.run("--spring.cloud.zookeeper.connectString=" + connectString,
+						"--debug=true",
+						//"--spring.cloud.bootstrap.enabled=false",
+						"--spring.config.import=zookeeper:",
+						"--spring.application.name=testZkConfigDataIntegration",
+						"--logging.level.org.springframework.cloud.zookeeper=DEBUG",
+						"--spring.cloud.zookeeper.config.root=" + ROOT);
+
+		this.curator = this.context.getBean(CuratorFramework.class);
+		this.environment = this.context.getEnvironment();
+	}
+
+	public void delete(String path) throws Exception {
+		try {
+			this.curator.delete().deletingChildrenIfNeeded().forPath(path);
+		}
+		catch (KeeperException e) {
+			if (e.code() != KeeperException.Code.NONODE) {
+				throw e;
+			}
+		}
+	}
+
+	@After
+	public void after() throws Exception {
+		try {
+			delete(ROOT);
+		}
+		finally {
+			this.context.close();
+			this.testingServer.close();
+		}
+	}
+
+	@Test
+	public void checkKeyValues() throws Exception {
+		String propValue = this.environment.getProperty(KEY_BASIC);
+		assertThat(propValue).as(KEY_BASIC + " was wrong").isEqualTo(VAL_BASIC);
+
+		propValue = this.environment.getProperty(KEY_NESTED);
+		assertThat(propValue).as(VAL_NESTED + " was wrong").isEqualTo(VAL_NESTED);
+
+		propValue = this.environment.getProperty(KEY_WITH_DOT);
+		assertThat(propValue).as(VAL_WITH_DOT + " was wrong").isEqualTo(VAL_WITH_DOT);
+
+		propValue = this.environment.getProperty(KEY_WITHOUT_VALUE);
+		assertThat(propValue).as(KEY_WITHOUT_VALUE + " was wrong").isEmpty();
+	}
+
+	@Test
+	public void propertyLoadedAndUpdated() throws Exception {
+		String testProp = this.environment.getProperty(KEY_BASIC);
+		assertThat(testProp).as("testProp was wrong").isEqualTo(VAL_BASIC);
+
+		this.curator.setData().forPath(KEY_BASIC_PATH, "testPropValUpdate".getBytes());
+
+		CountDownLatch latch = this.context.getBean(CountDownLatch.class);
+		boolean receivedEvent = latch.await(15, TimeUnit.SECONDS);
+		assertThat(receivedEvent).as("listener didn't receive event").isTrue();
+
+		testProp = this.environment.getProperty(KEY_BASIC);
+		assertThat(testProp).as("testProp was wrong after update")
+				.isEqualTo("testPropValUpdate");
+	}
+
+	@Configuration
+	@EnableAutoConfiguration
+	static class Config implements ApplicationListener<EnvironmentChangeEvent> {
+
+		@Bean
+		public CountDownLatch countDownLatch() {
+			return new CountDownLatch(1);
+		}
+
+		@Bean
+		public ContextRefresher contextRefresher(ConfigurableApplicationContext context,
+				RefreshScope scope) {
+			return new ConfigDataContextRefresher(context, scope);
+		}
+
+		@Override
+		public void onApplicationEvent(EnvironmentChangeEvent event) {
+			log.debug("Event keys: " + event.getKeys());
+			if (event.getKeys().contains(KEY_BASIC)) {
+				countDownLatch().countDown();
+			}
+		}
+
+	}
+
+}

spring-cloud-zookeeper-config/src/test/java/org/springframework/cloud/zookeeper/config/ZookeeperConfigDataNotOptionalIntegrationTests.java

@@ -0,0 +1,74 @@
+/*
+ * Copyright 2015-2019 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.cloud.zookeeper.config;
+
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.boot.WebApplicationType;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.builder.SpringApplicationBuilder;
+import org.springframework.boot.context.config.ConfigDataLocationNotFoundException;
+import org.springframework.cloud.context.refresh.ConfigDataContextRefresher;
+import org.springframework.cloud.context.refresh.ContextRefresher;
+import org.springframework.cloud.context.scope.refresh.RefreshScope;
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+/**
+ * @author Spencer Gibb
+ */
+public class ZookeeperConfigDataNotOptionalIntegrationTests {
+
+	@Test
+	public void configDataNotFoundThrowsException() {
+		Assertions.assertThatThrownBy(() -> {
+			ConfigurableApplicationContext context = null;
+			try {
+				context = new SpringApplicationBuilder(Config.class).web(WebApplicationType.NONE).run(
+						"--spring.cloud.zookeeper.connect-string=notexistantdomain:5000", "--debug=true",
+						"--spring.cloud.zookeeper.max-retries=0",
+						"--spring.cloud.zookeeper.blockUntilConnectedWait=1",
+						"--spring.cloud.zookeeper.blockUntilConnectedUnit=MILLISECONDS",
+						"--spring.cloud.zookeeper.connection-timeout=1ms",
+						"--spring.config.import=zookeeper:",
+						"--spring.application.name=testZkConfigDataNotOptionalIntegration",
+						"--logging.level.org.springframework.cloud.zookeeper=DEBUG",
+						"--spring.cloud.zookeeper.config.root=/shouldfail");
+
+			}
+			finally {
+				if (context != null) {
+					context.close();
+				}
+			}
+		}).isInstanceOf(ConfigDataLocationNotFoundException.class);
+	}
+
+	@Configuration
+	@EnableAutoConfiguration
+	static class Config {
+
+		@Bean
+		public ContextRefresher contextRefresher(ConfigurableApplicationContext context, RefreshScope scope) {
+			return new ConfigDataContextRefresher(context, scope);
+		}
+
+	}
+
+}

spring-cloud-zookeeper-config/src/test/java/org/springframework/cloud/zookeeper/config/ZookeeperPropertySourceLocatorFailFastTests.java

@@ -20,8 +20,9 @@ import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
 
+import org.springframework.boot.SpringBootConfiguration;
 import org.springframework.boot.WebApplicationType;
-import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.builder.SpringApplicationBuilder;
 
 import static org.assertj.core.api.Assertions.assertThatCode;
@@ -78,7 +79,8 @@ public class ZookeeperPropertySourceLocatorFailFastTests {
 				.isNotNull();
 	}
 
-	@SpringBootApplication
+	@SpringBootConfiguration
+	@EnableAutoConfiguration
 	static class Config {
 
 	}

spring-cloud-zookeeper-core/src/main/java/org/springframework/cloud/zookeeper/ZookeeperProperties.java

@@ -30,9 +30,13 @@ import org.springframework.util.Assert;
  * @author Spencer Gibb
  * @since 1.0.0
  */
-@ConfigurationProperties("spring.cloud.zookeeper")
+@ConfigurationProperties(ZookeeperProperties.PREFIX)
 public class ZookeeperProperties {
 
+	/**
+	 * Configuration prefix.
+	 */
+	public static final String PREFIX = "spring.cloud.zookeeper";
 	/**
 	 * Connection string to the Zookeeper cluster.
 	 */

src/checkstyle/checkstyle-suppressions.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0"?>
+<!DOCTYPE suppressions PUBLIC
+		"-//Puppy Crawl//DTD Suppressions 1.1//EN"
+		"https://www.puppycrawl.com/dtds/suppressions_1_1.dtd">
+<suppressions>
+<suppress files=".*ZookeeperPropertySourceLocatorTests\.java" checks="JavadocVariable"/>
+</suppressions>