Add FilteredClassLoader

Add `FilteredClassLoader` to replace `HideClassesClassLoader` and
`HidePackagesClassLoader`.

Fixes gh-10303

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/condition/ConditionalOnJavaTests.java

@@ -25,7 +25,7 @@ import org.junit.Test;
 
 import org.springframework.boot.autoconfigure.condition.ConditionalOnJava.Range;
 import org.springframework.boot.system.JavaVersion;
-import org.springframework.boot.test.context.HideClassesClassLoader;
+import org.springframework.boot.test.context.FilteredClassLoader;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
 import org.springframework.boot.testsupport.Assume;
 import org.springframework.context.annotation.Bean;
@@ -105,7 +105,7 @@ public class ConditionalOnJavaTests {
 	}
 
 	private String getJavaVersion(Class<?>... hiddenClasses) throws Exception {
-		HideClassesClassLoader classLoader = new HideClassesClassLoader(hiddenClasses);
+		FilteredClassLoader classLoader = new FilteredClassLoader(hiddenClasses);
 		Class<?> javaVersionClass = classLoader.loadClass(JavaVersion.class.getName());
 		Method getJavaVersionMethod = ReflectionUtils.findMethod(javaVersionClass,
 				"getJavaVersion");

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/http/HttpMessageConvertersAutoConfigurationTests.java

@@ -28,7 +28,7 @@ import org.springframework.boot.autoconfigure.gson.GsonAutoConfiguration;
 import org.springframework.boot.autoconfigure.http.JacksonHttpMessageConvertersConfiguration.MappingJackson2HttpMessageConverterConfiguration;
 import org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration;
 import org.springframework.boot.autoconfigure.jsonb.JsonbAutoConfiguration;
-import org.springframework.boot.test.context.HidePackagesClassLoader;
+import org.springframework.boot.test.context.FilteredClassLoader;
 import org.springframework.boot.test.context.assertj.AssertableApplicationContext;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
 import org.springframework.boot.test.context.runner.ContextConsumer;
@@ -237,7 +237,7 @@ public class HttpMessageConvertersAutoConfigurationTests {
 	@Test
 	public void gsonIsPreferredIfJacksonIsNotAvailable() {
 		allOptionsRunner().withClassLoader(
-				new HidePackagesClassLoader(ObjectMapper.class.getPackage().getName()))
+				new FilteredClassLoader(ObjectMapper.class.getPackage().getName()))
 				.run((context) -> {
 					assertConverterBeanExists(context, GsonHttpMessageConverter.class,
 							"gsonHttpMessageConverter");
@@ -250,8 +250,8 @@ public class HttpMessageConvertersAutoConfigurationTests {
 	@Test
 	public void jsonbIsPreferredIfJacksonAndGsonAreNotAvailable() {
 		allOptionsRunner()
-				.withClassLoader(new HidePackagesClassLoader(
-						ObjectMapper.class.getPackage().getName(),
+				.withClassLoader(
+						new FilteredClassLoader(ObjectMapper.class.getPackage().getName(),
 								Gson.class.getPackage().getName()))
 				.run(assertConverter(JsonbHttpMessageConverter.class,
 						"jsonbHttpMessageConverter"));

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/jdbc/DataSourceAutoConfigurationTests.java

@@ -42,7 +42,7 @@ import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.AutoConfigurations;
 import org.springframework.boot.jdbc.DatabaseDriver;
 import org.springframework.boot.jdbc.EmbeddedDatabaseConnection;
-import org.springframework.boot.test.context.HidePackagesClassLoader;
+import org.springframework.boot.test.context.FilteredClassLoader;
 import org.springframework.boot.test.context.assertj.AssertableApplicationContext;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
 import org.springframework.context.annotation.Bean;
@@ -166,9 +166,9 @@ public class DataSourceAutoConfigurationTests {
 	@Test
 	public void explicitTypeNoSupportedDataSource() {
 		this.contextRunner
-				.withClassLoader(new HidePackagesClassLoader("org.apache.tomcat",
-						"com.zaxxer.hikari", "org.apache.commons.dbcp",
-						"org.apache.commons.dbcp2"))
+				.withClassLoader(
+						new FilteredClassLoader("org.apache.tomcat", "com.zaxxer.hikari",
+								"org.apache.commons.dbcp", "org.apache.commons.dbcp2"))
 				.withPropertyValues(
 						"spring.datasource.driverClassName:org.hsqldb.jdbcDriver",
 						"spring.datasource.url:jdbc:hsqldb:mem:testdb",
@@ -227,7 +227,7 @@ public class DataSourceAutoConfigurationTests {
 
 	private <T extends DataSource> void assertDataSource(Class<T> expectedType,
 			List<String> hiddenPackages, Consumer<T> consumer) {
-		HidePackagesClassLoader classLoader = new HidePackagesClassLoader(
+		FilteredClassLoader classLoader = new FilteredClassLoader(
 				hiddenPackages.toArray(new String[hiddenPackages.size()]));
 		this.contextRunner.withClassLoader(classLoader).run((context) -> {
 			DataSource bean = context.getBean(DataSource.class);

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/jdbc/DataSourcePropertiesTests.java

@@ -21,7 +21,7 @@ import org.junit.Test;
 import org.junit.rules.ExpectedException;
 
 import org.springframework.boot.jdbc.EmbeddedDatabaseConnection;
-import org.springframework.boot.test.context.HidePackagesClassLoader;
+import org.springframework.boot.test.context.FilteredClassLoader;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -69,7 +69,7 @@ public class DataSourcePropertiesTests {
 	public void determineUrlWithNoEmbeddedSupport() throws Exception {
 		DataSourceProperties properties = new DataSourceProperties();
 		properties.setBeanClassLoader(
-				new HidePackagesClassLoader("org.h2", "org.apache.derby", "org.hsqldb"));
+				new FilteredClassLoader("org.h2", "org.apache.derby", "org.hsqldb"));
 		properties.afterPropertiesSet();
 		this.thrown.expect(DataSourceProperties.DataSourceBeanCreationException.class);
 		this.thrown.expectMessage("Cannot determine embedded database url");

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/session/ReactiveSessionAutoConfigurationMongoTests.java

@@ -25,7 +25,7 @@ import org.springframework.boot.autoconfigure.data.mongo.MongoReactiveDataAutoCo
 import org.springframework.boot.autoconfigure.mongo.MongoAutoConfiguration;
 import org.springframework.boot.autoconfigure.mongo.MongoReactiveAutoConfiguration;
 import org.springframework.boot.autoconfigure.mongo.embedded.EmbeddedMongoAutoConfiguration;
-import org.springframework.boot.test.context.HideClassesClassLoader;
+import org.springframework.boot.test.context.FilteredClassLoader;
 import org.springframework.boot.test.context.assertj.AssertableReactiveWebApplicationContext;
 import org.springframework.boot.test.context.runner.ContextConsumer;
 import org.springframework.boot.test.context.runner.ReactiveWebApplicationContextRunner;
@@ -59,7 +59,7 @@ public class ReactiveSessionAutoConfigurationMongoTests
 	@Test
 	public void defaultConfigWithUniqueStoreImplementation() {
 		this.contextRunner
-				.withClassLoader(new HideClassesClassLoader(
+				.withClassLoader(new FilteredClassLoader(
 						ReactiveRedisOperationsSessionRepository.class))
 				.withConfiguration(AutoConfigurations.of(
 						EmbeddedMongoAutoConfiguration.class,

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/session/ReactiveSessionAutoConfigurationRedisTests.java

@@ -25,7 +25,7 @@ import org.springframework.boot.autoconfigure.condition.ConditionEvaluationRepor
 import org.springframework.boot.autoconfigure.data.redis.RedisAutoConfiguration;
 import org.springframework.boot.autoconfigure.data.redis.RedisReactiveAutoConfiguration;
 import org.springframework.boot.autoconfigure.logging.ConditionEvaluationReportMessage;
-import org.springframework.boot.test.context.HideClassesClassLoader;
+import org.springframework.boot.test.context.FilteredClassLoader;
 import org.springframework.boot.test.context.assertj.AssertableReactiveWebApplicationContext;
 import org.springframework.boot.test.context.runner.ContextConsumer;
 import org.springframework.boot.test.context.runner.ReactiveWebApplicationContextRunner;
@@ -62,7 +62,7 @@ public class ReactiveSessionAutoConfigurationRedisTests
 	@Test
 	public void defaultConfigWithUniqueStoreImplementation() {
 		this.contextRunner
-				.withClassLoader(new HideClassesClassLoader(
+				.withClassLoader(new FilteredClassLoader(
 						ReactiveMongoOperationsSessionRepository.class))
 				.withConfiguration(AutoConfigurations.of(RedisAutoConfiguration.class,
 						RedisReactiveAutoConfiguration.class))

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/session/SessionAutoConfigurationHazelcastTests.java

@@ -22,7 +22,7 @@ import org.junit.Test;
 
 import org.springframework.beans.DirectFieldAccessor;
 import org.springframework.boot.autoconfigure.AutoConfigurations;
-import org.springframework.boot.test.context.HideClassesClassLoader;
+import org.springframework.boot.test.context.FilteredClassLoader;
 import org.springframework.boot.test.context.assertj.AssertableWebApplicationContext;
 import org.springframework.boot.test.context.runner.WebApplicationContextRunner;
 import org.springframework.context.annotation.Bean;
@@ -61,7 +61,7 @@ public class SessionAutoConfigurationHazelcastTests
 	public void defaultConfigWithUniqueStoreImplementation() {
 		this.contextRunner
 				.withClassLoader(
-						new HideClassesClassLoader(JdbcOperationsSessionRepository.class,
+						new FilteredClassLoader(JdbcOperationsSessionRepository.class,
 								RedisOperationsSessionRepository.class,
 								MongoOperationsSessionRepository.class))
 				.run(this::validateDefaultConfig);

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/session/SessionAutoConfigurationJdbcTests.java

@@ -27,7 +27,7 @@ import org.springframework.boot.autoconfigure.jdbc.DataSourceTransactionManagerA
 import org.springframework.boot.autoconfigure.jdbc.JdbcTemplateAutoConfiguration;
 import org.springframework.boot.autoconfigure.session.JdbcSessionConfiguration.SpringBootJdbcHttpSessionConfiguration;
 import org.springframework.boot.jdbc.DataSourceInitializationMode;
-import org.springframework.boot.test.context.HideClassesClassLoader;
+import org.springframework.boot.test.context.FilteredClassLoader;
 import org.springframework.boot.test.context.assertj.AssertableWebApplicationContext;
 import org.springframework.boot.test.context.runner.WebApplicationContextRunner;
 import org.springframework.boot.web.servlet.FilterRegistrationBean;
@@ -67,8 +67,7 @@ public class SessionAutoConfigurationJdbcTests
 	@Test
 	public void defaultConfigWithUniqueStoreImplementation() {
 		this.contextRunner
-				.withClassLoader(
-						new HideClassesClassLoader(HazelcastSessionRepository.class,
+				.withClassLoader(new FilteredClassLoader(HazelcastSessionRepository.class,
 						MongoOperationsSessionRepository.class,
 						RedisOperationsSessionRepository.class))
 				.run(this::validateDefaultConfig);

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/session/SessionAutoConfigurationMongoTests.java

@@ -23,7 +23,7 @@ import org.springframework.boot.autoconfigure.AutoConfigurations;
 import org.springframework.boot.autoconfigure.data.mongo.MongoDataAutoConfiguration;
 import org.springframework.boot.autoconfigure.mongo.MongoAutoConfiguration;
 import org.springframework.boot.autoconfigure.mongo.embedded.EmbeddedMongoAutoConfiguration;
-import org.springframework.boot.test.context.HideClassesClassLoader;
+import org.springframework.boot.test.context.FilteredClassLoader;
 import org.springframework.boot.test.context.assertj.AssertableWebApplicationContext;
 import org.springframework.boot.test.context.runner.ContextConsumer;
 import org.springframework.boot.test.context.runner.WebApplicationContextRunner;
@@ -57,8 +57,7 @@ public class SessionAutoConfigurationMongoTests
 	@Test
 	public void defaultConfigWithUniqueStoreImplementation() {
 		this.contextRunner
-				.withClassLoader(
-						new HideClassesClassLoader(HazelcastSessionRepository.class,
+				.withClassLoader(new FilteredClassLoader(HazelcastSessionRepository.class,
 						JdbcOperationsSessionRepository.class,
 						RedisOperationsSessionRepository.class))
 				.withConfiguration(AutoConfigurations.of(

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/session/SessionAutoConfigurationRedisTests.java

@@ -23,7 +23,7 @@ import org.springframework.beans.DirectFieldAccessor;
 import org.springframework.boot.autoconfigure.AutoConfigurations;
 import org.springframework.boot.autoconfigure.data.redis.RedisAutoConfiguration;
 import org.springframework.boot.autoconfigure.session.RedisSessionConfiguration.SpringBootRedisHttpSessionConfiguration;
-import org.springframework.boot.test.context.HideClassesClassLoader;
+import org.springframework.boot.test.context.FilteredClassLoader;
 import org.springframework.boot.test.context.assertj.AssertableWebApplicationContext;
 import org.springframework.boot.test.context.runner.ContextConsumer;
 import org.springframework.boot.test.context.runner.WebApplicationContextRunner;
@@ -62,8 +62,7 @@ public class SessionAutoConfigurationRedisTests
 	@Test
 	public void defaultConfigWithUniqueStoreImplementation() {
 		this.contextRunner
-				.withClassLoader(
-						new HideClassesClassLoader(HazelcastSessionRepository.class,
+				.withClassLoader(new FilteredClassLoader(HazelcastSessionRepository.class,
 						JdbcOperationsSessionRepository.class,
 						MongoOperationsSessionRepository.class))
 				.withConfiguration(AutoConfigurations.of(RedisAutoConfiguration.class))

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/context/HidePackagesClassLoader.java → spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/context/FilteredClassLoader.java

@@ -18,37 +18,109 @@ package org.springframework.boot.test.context;
 
 import java.net.URL;
 import java.net.URLClassLoader;
+import java.util.function.Predicate;
 
 /**
- * Test {@link URLClassLoader} that hides configurable packages. No class in one of those
- * packages or sub-packages are visible.
+ * Test {@link URLClassLoader} that can filter the classes it can load.
  *
  * @author Andy Wilkinson
  * @author Stephane Nicoll
+ * @author Phillip Webb
  * @since 2.0.0
  */
-public final class HidePackagesClassLoader extends URLClassLoader {
+public class FilteredClassLoader extends URLClassLoader {
 
-	private final String[] hiddenPackages;
+	private final Predicate<String>[] filters;
+
+	/**
+	 * Create a {@link FilteredClassLoader} that hides the given classes.
+	 * @param hiddenClasses the classes to hide
+	 */
+	public FilteredClassLoader(Class<?>... hiddenClasses) {
+		this(ClassFilter.of(hiddenClasses));
+	}
 
 	/**
-	 * Create a new instance with the packages to hide.
+	 * Create a {@link FilteredClassLoader} that hides classes from the given packages.
 	 * @param hiddenPackages the packages to hide
 	 */
-	public HidePackagesClassLoader(String... hiddenPackages) {
-		super(new URL[0], HidePackagesClassLoader.class.getClassLoader());
-		this.hiddenPackages = hiddenPackages;
+	public FilteredClassLoader(String... hiddenPackages) {
+		this(PackageFilter.of(hiddenPackages));
+	}
+
+	/**
+	 * Create a {@link FilteredClassLoader} that filters based on the given predicate.
+	 * @param filters a set of filters to determine when a class name should be hidden. A
+	 * {@link Predicate#test(Object) result} of {@code true} indicates a filtered class.
+	 */
+	@SafeVarargs
+	public FilteredClassLoader(Predicate<String>... filters) {
+		super(new URL[0], FilteredClassLoader.class.getClassLoader());
+		this.filters = filters;
 	}
 
 	@Override
 	protected Class<?> loadClass(String name, boolean resolve)
 			throws ClassNotFoundException {
-		for (String hiddenPackage : this.hiddenPackages) {
-			if (name.startsWith(hiddenPackage)) {
+		for (Predicate<String> filter : this.filters) {
+			if (filter.test(name)) {
 				throw new ClassNotFoundException();
 			}
 		}
 		return super.loadClass(name, resolve);
 	}
 
+	/**
+	 * Filter to restrict the classes that can be loaded.
+	 */
+	public final static class ClassFilter implements Predicate<String> {
+
+		private Class<?>[] hiddenClasses;
+
+		private ClassFilter(Class<?>[] hiddenClasses) {
+			this.hiddenClasses = hiddenClasses;
+		}
+
+		@Override
+		public boolean test(String className) {
+			for (Class<?> hiddenClass : this.hiddenClasses) {
+				if (className.equals(hiddenClass.getName())) {
+					return true;
+				}
+			}
+			return false;
+		}
+
+		public static ClassFilter of(Class<?>... hiddenClasses) {
+			return new ClassFilter(hiddenClasses);
+		}
+
+	}
+
+	/**
+	 * Filter to restrict the packages that can be loaded.
+	 */
+	public final static class PackageFilter implements Predicate<String> {
+
+		private final String[] hiddenPackages;
+
+		private PackageFilter(String[] hiddenPackages) {
+			this.hiddenPackages = hiddenPackages;
+		}
+
+		@Override
+		public boolean test(String className) {
+			for (String hiddenPackage : this.hiddenPackages) {
+				if (className.startsWith(hiddenPackage)) {
+					return true;
+				}
+			}
+			return false;
+		}
+
+		public static PackageFilter of(String... hiddenPackages) {
+			return new PackageFilter(hiddenPackages);
+		}
+
+	}
 }

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/context/runner/AbstractApplicationContextRunner.java

@@ -23,7 +23,7 @@ import java.util.function.Supplier;
 
 import org.springframework.boot.context.annotation.Configurations;
 import org.springframework.boot.context.annotation.UserConfigurations;
-import org.springframework.boot.test.context.HidePackagesClassLoader;
+import org.springframework.boot.test.context.FilteredClassLoader;
 import org.springframework.boot.test.context.assertj.ApplicationContextAssert;
 import org.springframework.boot.test.context.assertj.ApplicationContextAssertProvider;
 import org.springframework.boot.test.util.TestPropertyValues;
@@ -180,7 +180,7 @@ abstract class AbstractApplicationContextRunner<SELF extends AbstractApplication
 	 * the classpath.
 	 * @param classLoader the classloader to use (can be null to use the default)
 	 * @return a new instance with the updated class loader
-	 * @see HidePackagesClassLoader
+	 * @see FilteredClassLoader
 	 */
 	public SELF withClassLoader(ClassLoader classLoader) {
 		return newInstance(this.contextFactory, this.environmentProperties,

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/context/HideClassesClassLoader.java → spring-boot-project/spring-boot-test/src/test/java/org/springframework/boot/test/context/FilteredClassLoaderTests.java

@@ -16,33 +16,47 @@
 
 package org.springframework.boot.test.context;
 
-import java.net.URL;
-import java.net.URLClassLoader;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+
+import static org.assertj.core.api.Assertions.assertThat;
 
 /**
- * Test {@link URLClassLoader} that hides configurable classes.
+ * Tests for {@link FilteredClassLoader}.
  *
- * @author Stephane Nicoll
- * @since 2.0.0
+ * @author Phillip Webb
  */
-public class HideClassesClassLoader extends URLClassLoader {
+public class FilteredClassLoaderTests {
 
-	private final Class<?>[] hiddenClasses;
+	@Rule
+	public ExpectedException thrown = ExpectedException.none();
 
-	public HideClassesClassLoader(Class<?>... hiddenClasses) {
-		super(new URL[0], HideClassesClassLoader.class.getClassLoader());
-		this.hiddenClasses = hiddenClasses;
+	@Test
+	public void loadClassWhenFilteredOnPackageShouldThrowClassNotFound()
+			throws Exception {
+		FilteredClassLoader classLoader = new FilteredClassLoader(
+				FilteredClassLoaderTests.class.getPackage().getName());
+		this.thrown.expect(ClassNotFoundException.class);
+		classLoader.loadClass(getClass().getName());
+		classLoader.close();
 	}
 
-	@Override
-	protected Class<?> loadClass(String name, boolean resolve)
-			throws ClassNotFoundException {
-		for (Class<?> hiddenClass : this.hiddenClasses) {
-			if (name.equals(hiddenClass.getName())) {
-				throw new ClassNotFoundException();
-			}
+	@Test
+	public void loadClassWhenFilteredOnClassShouldThrowClassNotFound() throws Exception {
+		FilteredClassLoader classLoader = new FilteredClassLoader(
+				FilteredClassLoaderTests.class);
+		this.thrown.expect(ClassNotFoundException.class);
+		classLoader.loadClass(getClass().getName());
+		classLoader.close();
 	}
-		return super.loadClass(name, resolve);
+
+	@Test
+	public void loadClassWhenNotFilteredShouldLoadClass() throws Exception {
+		FilteredClassLoader classLoader = new FilteredClassLoader((className) -> false);
+		Class<?> loaded = classLoader.loadClass(getClass().getName());
+		assertThat(loaded.getName()).isEqualTo(getClass().getName());
+		classLoader.close();
 	}
 
 }

spring-boot-project/spring-boot-test/src/test/java/org/springframework/boot/test/context/runner/AbstractApplicationContextRunnerTests.java

@@ -25,7 +25,7 @@ import org.junit.Test;
 import org.junit.rules.ExpectedException;
 
 import org.springframework.boot.context.annotation.UserConfigurations;
-import org.springframework.boot.test.context.HidePackagesClassLoader;
+import org.springframework.boot.test.context.FilteredClassLoader;
 import org.springframework.boot.test.context.assertj.ApplicationContextAssertProvider;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.Bean;
@@ -34,7 +34,7 @@ import org.springframework.core.env.Environment;
 import org.springframework.util.ClassUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.assertj.core.api.Assertions.fail;
+import static org.junit.Assert.fail;
 
 /**
  * Abstract tests for {@link AbstractApplicationContextRunner} implementations.
@@ -148,8 +148,7 @@ public abstract class AbstractApplicationContextRunnerTests<T extends AbstractAp
 
 	@Test
 	public void runWithClassLoaderShouldSetClassLoader() throws Exception {
-		get().withClassLoader(
-				new HidePackagesClassLoader(Gson.class.getPackage().getName()))
+		get().withClassLoader(new FilteredClassLoader(Gson.class.getPackage().getName()))
 				.run((context) -> {
 					try {
 						ClassUtils.forName(Gson.class.getName(),