Add nullability annotations to tests in module/spring-boot-jdbc

See gh-47263

module/spring-boot-jdbc/build.gradle

@@ -77,6 +77,8 @@ dependencies {
 	}
 	testImplementation("tools.jackson.core:jackson-databind")
 
+	testCompileOnly("org.checkerframework:checker-qual")
+
 	testRuntimeOnly("ch.qos.logback:logback-classic")
 	testRuntimeOnly("com.clickhouse:clickhouse-jdbc")
 	testRuntimeOnly("com.mysql:mysql-connector-j")
@@ -102,3 +104,11 @@ tasks.named("checkSpringConfigurationMetadata").configure {
 		"spring.datasource.tomcat.*",
 	]
 }
+
+tasks.named("compileTestJava") {
+	options.nullability.checking = "tests"
+}
+
+tasks.named("compileDockerTestJava") {
+	options.nullability.checking = "tests"
+}

module/spring-boot-jdbc/src/dockerTest/java/org/springframework/boot/jdbc/docker/compose/ClickHouseJdbcDockerComposeConnectionDetailsFactoryIntegrationTests.java

@@ -56,7 +56,9 @@ class ClickHouseJdbcDockerComposeConnectionDetailsFactoryIntegrationTests {
 		dataSource.setDriverClass((Class<? extends Driver>) ClassUtils.forName(connectionDetails.getDriverClassName(),
 				getClass().getClassLoader()));
 		JdbcTemplate template = new JdbcTemplate(dataSource);
-		assertThat(template.queryForObject(DatabaseDriver.CLICKHOUSE.getValidationQuery(), Integer.class)).isEqualTo(1);
+		String validationQuery = DatabaseDriver.CLICKHOUSE.getValidationQuery();
+		assertThat(validationQuery).isNotNull();
+		assertThat(template.queryForObject(validationQuery, Integer.class)).isEqualTo(1);
 	}
 
 }

module/spring-boot-jdbc/src/dockerTest/java/org/springframework/boot/jdbc/docker/compose/OracleFreeJdbcDockerComposeConnectionDetailsFactoryIntegrationTests.java

@@ -53,8 +53,9 @@ class OracleFreeJdbcDockerComposeConnectionDetailsFactoryIntegrationTests {
 				getClass().getClassLoader()));
 		Awaitility.await().atMost(Duration.ofMinutes(1)).ignoreExceptions().untilAsserted(() -> {
 			JdbcTemplate template = new JdbcTemplate(dataSource);
-			assertThat(template.queryForObject(DatabaseDriver.ORACLE.getValidationQuery(), String.class))
+			String validationQuery = DatabaseDriver.ORACLE.getValidationQuery();
-				.isEqualTo("Hello");
+			assertThat(validationQuery).isNotNull();
+			assertThat(template.queryForObject(validationQuery, String.class)).isEqualTo("Hello");
 		});
 	}
 

module/spring-boot-jdbc/src/dockerTest/java/org/springframework/boot/jdbc/docker/compose/OracleXeJdbcDockerComposeConnectionDetailsFactoryIntegrationTests.java

@@ -57,8 +57,9 @@ class OracleXeJdbcDockerComposeConnectionDetailsFactoryIntegrationTests {
 				getClass().getClassLoader()));
 		Awaitility.await().atMost(Duration.ofMinutes(1)).ignoreExceptions().untilAsserted(() -> {
 			JdbcTemplate template = new JdbcTemplate(dataSource);
-			assertThat(template.queryForObject(DatabaseDriver.ORACLE.getValidationQuery(), String.class))
+			String validationQuery = DatabaseDriver.ORACLE.getValidationQuery();
-				.isEqualTo("Hello");
+			assertThat(validationQuery).isNotNull();
+			assertThat(template.queryForObject(validationQuery, String.class)).isEqualTo("Hello");
 		});
 	}
 

module/spring-boot-jdbc/src/dockerTest/java/org/springframework/boot/jdbc/docker/compose/PostgresJdbcDockerComposeConnectionDetailsFactoryIntegrationTests.java

@@ -18,6 +18,8 @@ package org.springframework.boot.jdbc.docker.compose;
 
 import java.sql.Driver;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.boot.docker.compose.service.connection.test.DockerComposeTest;
 import org.springframework.boot.jdbc.DatabaseDriver;
 import org.springframework.boot.jdbc.autoconfigure.JdbcConnectionDetails;
@@ -72,12 +74,13 @@ class PostgresJdbcDockerComposeConnectionDetailsFactoryIntegrationTests {
 	}
 
 	private void checkDatabaseAccess(JdbcConnectionDetails connectionDetails) throws ClassNotFoundException {
-		assertThat(executeQuery(connectionDetails, DatabaseDriver.POSTGRESQL.getValidationQuery(), Integer.class))
+		String validationQuery = DatabaseDriver.POSTGRESQL.getValidationQuery();
-			.isEqualTo(1);
+		assertThat(validationQuery).isNotNull();
+		assertThat(executeQuery(connectionDetails, validationQuery, Integer.class)).isEqualTo(1);
 	}
 
 	@SuppressWarnings("unchecked")
-	private <T> T executeQuery(JdbcConnectionDetails connectionDetails, String sql, Class<T> resultClass)
+	private <T> @Nullable T executeQuery(JdbcConnectionDetails connectionDetails, String sql, Class<T> resultClass)
 			throws ClassNotFoundException {
 		SimpleDriverDataSource dataSource = new SimpleDriverDataSource();
 		dataSource.setUrl(connectionDetails.getJdbcUrl());

module/spring-boot-jdbc/src/dockerTest/java/org/springframework/boot/jdbc/docker/compose/SqlServerJdbcDockerComposeConnectionDetailsFactoryIntegrationTests.java

@@ -68,7 +68,9 @@ class SqlServerJdbcDockerComposeConnectionDetailsFactoryIntegrationTests {
 		dataSource.setDriverClass((Class<? extends Driver>) ClassUtils.forName(connectionDetails.getDriverClassName(),
 				getClass().getClassLoader()));
 		JdbcTemplate template = new JdbcTemplate(dataSource);
-		assertThat(template.queryForObject(DatabaseDriver.SQLSERVER.getValidationQuery(), Integer.class)).isEqualTo(1);
+		String validationQuery = DatabaseDriver.SQLSERVER.getValidationQuery();
+		assertThat(validationQuery).isNotNull();
+		assertThat(template.queryForObject(validationQuery, Integer.class)).isEqualTo(1);
 	}
 
 }

module/spring-boot-jdbc/src/dockerTest/java/org/springframework/boot/jdbc/testcontainers/JdbcContainerConnectionDetailsFactoryTests.java

@@ -60,7 +60,9 @@ class JdbcContainerConnectionDetailsFactoryTests {
 	void connectionCanBeMadeToJdbcContainer() {
 		assertThat(this.connectionDetails).isNotNull();
 		JdbcTemplate jdbc = new JdbcTemplate(this.dataSource);
-		assertThatNoException().isThrownBy(() -> jdbc.execute(DatabaseDriver.POSTGRESQL.getValidationQuery()));
+		String validationQuery = DatabaseDriver.POSTGRESQL.getValidationQuery();
+		assertThat(validationQuery).isNotNull();
+		assertThatNoException().isThrownBy(() -> jdbc.execute(validationQuery));
 	}
 
 	@Configuration(proxyBeanMethods = false)

module/spring-boot-jdbc/src/test/java/org/springframework/boot/jdbc/DataSourceBuilderRuntimeHintsTests.java

@@ -49,6 +49,7 @@ class DataSourceBuilderRuntimeHintsTests {
 				TypeHint typeHint = hints.getTypeHint(dataSourceType);
 				assertThat(typeHint).withFailMessage(() -> "No hints found for data source type " + dataSourceType)
 					.isNotNull();
+				assertThat(typeHint).isNotNull();
 				Set<MemberCategory> memberCategories = typeHint.getMemberCategories();
 				assertThat(memberCategories).containsExactly(MemberCategory.INVOKE_PUBLIC_CONSTRUCTORS);
 			});

module/spring-boot-jdbc/src/test/java/org/springframework/boot/jdbc/DataSourceBuilderTests.java

@@ -39,6 +39,7 @@ import oracle.ucp.jdbc.PoolDataSourceImpl;
 import org.apache.commons.dbcp2.BasicDataSource;
 import org.h2.Driver;
 import org.h2.jdbcx.JdbcDataSource;
+import org.jspecify.annotations.Nullable;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.Test;
 import org.postgresql.ds.PGSimpleDataSource;
@@ -63,7 +64,7 @@ import static org.assertj.core.api.Assertions.assertThatNoException;
  */
 class DataSourceBuilderTests {
 
-	private DataSource dataSource;
+	private @Nullable DataSource dataSource;
 
 	@AfterEach
 	void shutdownDataSource() throws IOException {
@@ -621,33 +622,33 @@ class DataSourceBuilderTests {
 
 	static class CustomTomcatDataSource extends org.apache.tomcat.jdbc.pool.DataSource {
 
-		private String jdbcUrl;
+		private @Nullable String jdbcUrl;
 
-		private String user;
+		private @Nullable String user;
 
-		private String driverClass;
+		private @Nullable String driverClass;
 
-		String getJdbcUrl() {
+		@Nullable String getJdbcUrl() {
 			return this.jdbcUrl;
 		}
 
-		void setJdbcUrl(String jdbcUrl) {
+		void setJdbcUrl(@Nullable String jdbcUrl) {
 			this.jdbcUrl = jdbcUrl;
 		}
 
-		String getUser() {
+		@Nullable String getUser() {
 			return this.user;
 		}
 
-		void setUser(String user) {
+		void setUser(@Nullable String user) {
 			this.user = user;
 		}
 
-		String getDriverClass() {
+		@Nullable String getDriverClass() {
 			return this.driverClass;
 		}
 
-		void setDriverClass(String driverClass) {
+		void setDriverClass(@Nullable String driverClass) {
 			this.driverClass = driverClass;
 		}
 
@@ -655,9 +656,9 @@ class DataSourceBuilderTests {
 
 	static class LimitedCustomDataSource extends AbstractDataSource {
 
-		private String username;
+		private @Nullable String username;
 
-		private String password;
+		private @Nullable String password;
 
 		@Override
 		public Connection getConnection() throws SQLException {
@@ -669,19 +670,19 @@ class DataSourceBuilderTests {
 			throw new UnsupportedOperationException();
 		}
 
-		String getUsername() {
+		@Nullable String getUsername() {
 			return this.username;
 		}
 
-		void setUsername(String username) {
+		void setUsername(@Nullable String username) {
 			this.username = username;
 		}
 
-		String getPassword() {
+		@Nullable String getPassword() {
 			return this.password;
 		}
 
-		void setPassword(String password) {
+		void setPassword(@Nullable String password) {
 			this.password = password;
 		}
 
@@ -689,13 +690,13 @@ class DataSourceBuilderTests {
 
 	static class NoDriverClassNameDataSource extends LimitedCustomDataSource {
 
-		private String url;
+		private @Nullable String url;
 
-		String getUrl() {
+		@Nullable String getUrl() {
 			return this.url;
 		}
 
-		void setUrl(String url) {
+		void setUrl(@Nullable String url) {
 			this.url = url;
 		}
 
@@ -703,23 +704,23 @@ class DataSourceBuilderTests {
 
 	static class CustomDataSource extends LimitedCustomDataSource {
 
-		private String driverClassName;
+		private @Nullable String driverClassName;
 
-		private String url;
+		private @Nullable String url;
 
-		String getDriverClassName() {
+		@Nullable String getDriverClassName() {
 			return this.driverClassName;
 		}
 
-		void setDriverClassName(String driverClassName) {
+		void setDriverClassName(@Nullable String driverClassName) {
 			this.driverClassName = driverClassName;
 		}
 
-		String getUrl() {
+		@Nullable String getUrl() {
 			return this.url;
 		}
 
-		void setUrl(String url) {
+		void setUrl(@Nullable String url) {
 			this.url = url;
 		}
 

module/spring-boot-jdbc/src/test/java/org/springframework/boot/jdbc/DatabaseDriverClassNameTests.java

@@ -29,6 +29,7 @@ import java.util.stream.Stream;
 
 import javax.sql.XADataSource;
 
+import org.jspecify.annotations.Nullable;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.MethodSource;
@@ -71,19 +72,20 @@ class DatabaseDriverClassNameTests {
 	}
 
 	static Stream<? extends Arguments> databaseClassIsOfRequiredType() {
-		return Stream.concat(argumentsForType(Driver.class, DatabaseDriver::getDriverClassName),
+		Function<DatabaseDriver, @Nullable String> getDriverClassName = DatabaseDriver::getDriverClassName;
+		return Stream.concat(argumentsForType(Driver.class, getDriverClassName),
 				argumentsForType(XADataSource.class,
 						(databaseDriver) -> databaseDriver.getXaDataSourceClassName() != null,
 						DatabaseDriver::getXaDataSourceClassName));
 	}
 
 	private static Stream<? extends Arguments> argumentsForType(Class<?> type,
-			Function<DatabaseDriver, String> classNameExtractor) {
+			Function<DatabaseDriver, @Nullable String> classNameExtractor) {
 		return argumentsForType(type, (databaseDriver) -> true, classNameExtractor);
 	}
 
 	private static Stream<? extends Arguments> argumentsForType(Class<?> type, Predicate<DatabaseDriver> predicate,
-			Function<DatabaseDriver, String> classNameExtractor) {
+			Function<DatabaseDriver, @Nullable String> classNameExtractor) {
 		return Stream.of(DatabaseDriver.values())
 			.filter((databaseDriver) -> !EXCLUDED_DRIVERS.contains(databaseDriver))
 			.filter(predicate)

module/spring-boot-jdbc/src/test/java/org/springframework/boot/jdbc/EmbeddedDatabaseConnectionTests.java

@@ -22,6 +22,7 @@ import java.sql.SQLException;
 
 import javax.sql.DataSource;
 
+import org.jspecify.annotations.Nullable;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.MethodSource;
@@ -61,6 +62,7 @@ class EmbeddedDatabaseConnectionTests {
 	}
 
 	@Test
+	@SuppressWarnings("NullAway") // Test null check
 	void getUrlWithNullDatabaseNameForHsqldb() {
 		assertThatIllegalArgumentException().isThrownBy(() -> EmbeddedDatabaseConnection.HSQLDB.getUrl(null))
 			.withMessageContaining("'databaseName' must not be empty");
@@ -142,7 +144,7 @@ class EmbeddedDatabaseConnectionTests {
 			.isEmbedded(mockDataSource(EmbeddedDatabaseConnection.H2.getDriverClassName(), null))).isTrue();
 	}
 
-	DataSource mockDataSource(String productName, String connectionUrl) throws SQLException {
+	DataSource mockDataSource(@Nullable String productName, @Nullable String connectionUrl) throws SQLException {
 		DatabaseMetaData metaData = mock(DatabaseMetaData.class);
 		given(metaData.getDatabaseProductName()).willReturn(productName);
 		given(metaData.getURL()).willReturn(connectionUrl);

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

@@ -37,6 +37,7 @@ import io.r2dbc.spi.ConnectionFactory;
 import oracle.ucp.jdbc.PoolDataSourceImpl;
 import org.apache.commons.dbcp2.BasicDataSource;
 import org.assertj.core.api.InstanceOfAssertFactories;
+import org.jspecify.annotations.Nullable;
 import org.junit.jupiter.api.Test;
 
 import org.springframework.beans.factory.BeanCreationException;
@@ -292,8 +293,9 @@ class DataSourceAutoConfigurationTests {
 			TestDataSource source = (TestDataSource) dataSource;
 			assertThat(source.getUsername()).isEqualTo("user-1");
 			assertThat(source.getPassword()).isEqualTo("password-1");
-			assertThat(source.getDriver().getClass().getName())
+			Driver driver = source.getDriver();
-				.isEqualTo(DatabaseDriver.POSTGRESQL.getDriverClassName());
+			assertThat(driver).isNotNull();
+			assertThat(driver.getClass().getName()).isEqualTo(DatabaseDriver.POSTGRESQL.getDriverClassName());
 			assertThat(source.getUrl()).isEqualTo("jdbc:customdb://customdb.example.com:12345/database-1");
 		});
 	}
@@ -326,7 +328,7 @@ class DataSourceAutoConfigurationTests {
 	@Configuration(proxyBeanMethods = false)
 	static class TestDataSourceConfiguration {
 
-		private BasicDataSource pool;
+		private @Nullable BasicDataSource pool;
 
 		@Bean
 		DataSource dataSource() {

module/spring-boot-jdbc/src/test/java/org/springframework/boot/jdbc/autoconfigure/DataSourceBeanCreationFailureAnalyzerTests.java

@@ -16,6 +16,7 @@
 
 package org.springframework.boot.jdbc.autoconfigure;
 
+import com.mchange.util.AssertException;
 import org.junit.jupiter.api.Test;
 
 import org.springframework.beans.factory.BeanCreationException;
@@ -62,7 +63,9 @@ class DataSourceBeanCreationFailureAnalyzerTests {
 		assertThat(failure).isNotNull();
 		DataSourceBeanCreationFailureAnalyzer failureAnalyzer = new DataSourceBeanCreationFailureAnalyzer(
 				this.environment);
-		return failureAnalyzer.analyze(failure);
+		FailureAnalysis analysis = failureAnalyzer.analyze(failure);
+		assertThat(analysis).isNotNull();
+		return analysis;
 	}
 
 	private BeanCreationException createFailure(Class<?> configuration) {
@@ -72,7 +75,7 @@ class DataSourceBeanCreationFailureAnalyzerTests {
 			context.register(configuration);
 			context.refresh();
 			context.close();
-			return null;
+			throw new AssertException("Shouldn't be reached!");
 		}
 		catch (BeanCreationException ex) {
 			return ex;

module/spring-boot-jdbc/src/test/java/org/springframework/boot/jdbc/autoconfigure/DataSourceInitializationAutoConfigurationTests.java

@@ -122,7 +122,8 @@ class DataSourceInitializationAutoConfigurationTests {
 
 		@Bean
 		DataSourceScriptDatabaseInitializer customInitializer() {
-			return new DataSourceScriptDatabaseInitializer(null, new DatabaseInitializationSettings()) {
+			return new DataSourceScriptDatabaseInitializer(mock(DataSource.class),
+					new DatabaseInitializationSettings()) {
 
 				@Override
 				protected void runScripts(Scripts scripts) {

module/spring-boot-jdbc/src/test/java/org/springframework/boot/jdbc/autoconfigure/Dbcp2JdbcConnectionDetailsBeanPostProcessorTests.java

@@ -19,9 +19,11 @@ package org.springframework.boot.jdbc.autoconfigure;
 import org.apache.commons.dbcp2.BasicDataSource;
 import org.junit.jupiter.api.Test;
 
+import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.jdbc.DatabaseDriver;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
 
 /**
  * Tests for {@link Dbcp2JdbcConnectionDetailsBeanPostProcessor}.
@@ -33,13 +35,14 @@ import static org.assertj.core.api.Assertions.assertThat;
 class Dbcp2JdbcConnectionDetailsBeanPostProcessorTests {
 
 	@Test
+	@SuppressWarnings("unchecked")
 	void setUsernamePasswordUrlAndDriverClassName() {
 		BasicDataSource dataSource = new BasicDataSource();
 		dataSource.setUrl("will-be-overwritten");
 		dataSource.setUsername("will-be-overwritten");
 		dataSource.setPassword("will-be-overwritten");
 		dataSource.setDriverClassName("will-be-overwritten");
-		new Dbcp2JdbcConnectionDetailsBeanPostProcessor(null).processDataSource(dataSource,
+		new Dbcp2JdbcConnectionDetailsBeanPostProcessor(mock(ObjectProvider.class)).processDataSource(dataSource,
 				new TestJdbcConnectionDetails());
 		assertThat(dataSource.getUrl()).isEqualTo("jdbc:customdb://customdb.example.com:12345/database-1");
 		assertThat(dataSource.getUserName()).isEqualTo("user-1");

module/spring-boot-jdbc/src/test/java/org/springframework/boot/jdbc/autoconfigure/EmbeddedDataSourceConfigurationTests.java

@@ -22,6 +22,7 @@ import java.sql.SQLException;
 
 import javax.sql.DataSource;
 
+import org.jspecify.annotations.Nullable;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.Test;
 
@@ -38,7 +39,7 @@ import static org.assertj.core.api.Assertions.assertThat;
  */
 class EmbeddedDataSourceConfigurationTests {
 
-	private AnnotationConfigApplicationContext context;
+	private @Nullable AnnotationConfigApplicationContext context;
 
 	@AfterEach
 	void closeContext() {

module/spring-boot-jdbc/src/test/java/org/springframework/boot/jdbc/autoconfigure/HikariDataSourceConfigurationTests.java

@@ -26,6 +26,7 @@ import javax.sql.DataSource;
 
 import com.zaxxer.hikari.HikariDataSource;
 import org.assertj.core.api.InstanceOfAssertFactories;
+import org.jspecify.annotations.Nullable;
 import org.junit.jupiter.api.Test;
 
 import org.springframework.beans.BeansException;
@@ -239,12 +240,12 @@ class HikariDataSourceConfigurationTests {
 	public static class MockDataSource implements DataSource {
 
 		@Override
-		public Logger getParentLogger() throws SQLFeatureNotSupportedException {
+		public @Nullable Logger getParentLogger() throws SQLFeatureNotSupportedException {
 			return null;
 		}
 
 		@Override
-		public <T> T unwrap(Class<T> iface) throws SQLException {
+		public <T> @Nullable T unwrap(Class<T> iface) throws SQLException {
 			return null;
 		}
 
@@ -264,7 +265,7 @@ class HikariDataSourceConfigurationTests {
 		}
 
 		@Override
-		public PrintWriter getLogWriter() throws SQLException {
+		public @Nullable PrintWriter getLogWriter() throws SQLException {
 			return null;
 		}
 

module/spring-boot-jdbc/src/test/java/org/springframework/boot/jdbc/autoconfigure/HikariDriverConfigurationFailureAnalyzerTests.java

@@ -16,7 +16,9 @@
 
 package org.springframework.boot.jdbc.autoconfigure;
 
+import com.mchange.util.AssertException;
 import com.zaxxer.hikari.HikariDataSource;
+import org.jspecify.annotations.Nullable;
 import org.junit.jupiter.api.Test;
 
 import org.springframework.beans.factory.BeanCreationException;
@@ -53,7 +55,7 @@ class HikariDriverConfigurationFailureAnalyzerTests {
 		assertThat(failureAnalysis).isNull();
 	}
 
-	private FailureAnalysis performAnalysis(Class<?> configuration) {
+	private @Nullable FailureAnalysis performAnalysis(Class<?> configuration) {
 		BeanCreationException failure = createFailure(configuration);
 		assertThat(failure).isNotNull();
 		return new HikariDriverConfigurationFailureAnalyzer().analyze(failure);
@@ -69,7 +71,7 @@ class HikariDriverConfigurationFailureAnalyzerTests {
 		try {
 			context.refresh();
 			context.close();
-			return null;
+			throw new AssertException("Shouldn't be reached!");
 		}
 		catch (BeanCreationException ex) {
 			return ex;

module/spring-boot-jdbc/src/test/java/org/springframework/boot/jdbc/autoconfigure/HikariJdbcConnectionDetailsBeanPostProcessorTests.java

@@ -19,6 +19,7 @@ package org.springframework.boot.jdbc.autoconfigure;
 import com.zaxxer.hikari.HikariDataSource;
 import org.junit.jupiter.api.Test;
 
+import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.jdbc.DatabaseDriver;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -34,13 +35,14 @@ import static org.mockito.Mockito.mock;
 class HikariJdbcConnectionDetailsBeanPostProcessorTests {
 
 	@Test
+	@SuppressWarnings("unchecked")
 	void setUsernamePasswordAndUrl() {
 		HikariDataSource dataSource = new HikariDataSource();
 		dataSource.setJdbcUrl("will-be-overwritten");
 		dataSource.setUsername("will-be-overwritten");
 		dataSource.setPassword("will-be-overwritten");
 		dataSource.setDriverClassName(DatabaseDriver.H2.getDriverClassName());
-		new HikariJdbcConnectionDetailsBeanPostProcessor(null).processDataSource(dataSource,
+		new HikariJdbcConnectionDetailsBeanPostProcessor(mock(ObjectProvider.class)).processDataSource(dataSource,
 				new TestJdbcConnectionDetails());
 		assertThat(dataSource.getJdbcUrl()).isEqualTo("jdbc:customdb://customdb.example.com:12345/database-1");
 		assertThat(dataSource.getUsername()).isEqualTo("user-1");
@@ -49,11 +51,13 @@ class HikariJdbcConnectionDetailsBeanPostProcessorTests {
 	}
 
 	@Test
+	@SuppressWarnings("unchecked")
 	void toleratesConnectionDetailsWithNullDriverClassName() {
 		HikariDataSource dataSource = new HikariDataSource();
 		dataSource.setDriverClassName(DatabaseDriver.H2.getDriverClassName());
 		JdbcConnectionDetails connectionDetails = mock(JdbcConnectionDetails.class);
-		new HikariJdbcConnectionDetailsBeanPostProcessor(null).processDataSource(dataSource, connectionDetails);
+		new HikariJdbcConnectionDetailsBeanPostProcessor(mock(ObjectProvider.class)).processDataSource(dataSource,
+				connectionDetails);
 		assertThat(dataSource.getDriverClassName()).isEqualTo(DatabaseDriver.H2.getDriverClassName());
 	}
 

module/spring-boot-jdbc/src/test/java/org/springframework/boot/jdbc/autoconfigure/JdbcTemplateAutoConfigurationTests.java

@@ -23,6 +23,7 @@ import java.lang.annotation.Target;
 
 import javax.sql.DataSource;
 
+import org.jspecify.annotations.Nullable;
 import org.junit.jupiter.api.Test;
 
 import org.springframework.boot.autoconfigure.AutoConfigurations;
@@ -262,7 +263,7 @@ class JdbcTemplateAutoConfigurationTests {
 
 	static class DataSourceInitializationValidator {
 
-		private final Integer count;
+		private final @Nullable Integer count;
 
 		DataSourceInitializationValidator(JdbcTemplate jdbcTemplate) {
 			this.count = jdbcTemplate.queryForObject("SELECT COUNT(*) from BAR", Integer.class);

module/spring-boot-jdbc/src/test/java/org/springframework/boot/jdbc/autoconfigure/JndiDataSourceAutoConfigurationTests.java

@@ -22,6 +22,7 @@ import javax.naming.Context;
 import javax.sql.DataSource;
 
 import org.apache.commons.dbcp2.BasicDataSource;
+import org.jspecify.annotations.Nullable;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -49,7 +50,7 @@ class JndiDataSourceAutoConfigurationTests {
 
 	private String initialContextFactory;
 
-	private AnnotationConfigApplicationContext context;
+	private @Nullable AnnotationConfigApplicationContext context;
 
 	@BeforeEach
 	void setupJndi() {

module/spring-boot-jdbc/src/test/java/org/springframework/boot/jdbc/autoconfigure/OracleUcpJdbcConnectionDetailsBeanPostProcessorTests.java

@@ -22,9 +22,11 @@ import oracle.ucp.jdbc.PoolDataSourceImpl;
 import oracle.ucp.util.OpaqueString;
 import org.junit.jupiter.api.Test;
 
+import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.jdbc.DatabaseDriver;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
 
 /**
  * Tests for {@link OracleUcpJdbcConnectionDetailsBeanPostProcessor}.
@@ -36,13 +38,14 @@ import static org.assertj.core.api.Assertions.assertThat;
 class OracleUcpJdbcConnectionDetailsBeanPostProcessorTests {
 
 	@Test
+	@SuppressWarnings("unchecked")
 	void setUsernamePasswordUrlAndDriverClassName() throws SQLException {
 		PoolDataSourceImpl dataSource = new PoolDataSourceImpl();
 		dataSource.setURL("will-be-overwritten");
 		dataSource.setUser("will-be-overwritten");
 		dataSource.setPassword("will-be-overwritten");
 		dataSource.setConnectionFactoryClassName("will-be-overwritten");
-		new OracleUcpJdbcConnectionDetailsBeanPostProcessor(null).processDataSource(dataSource,
+		new OracleUcpJdbcConnectionDetailsBeanPostProcessor(mock(ObjectProvider.class)).processDataSource(dataSource,
 				new TestJdbcConnectionDetails());
 		assertThat(dataSource.getURL()).isEqualTo("jdbc:customdb://customdb.example.com:12345/database-1");
 		assertThat(dataSource.getUser()).isEqualTo("user-1");

module/spring-boot-jdbc/src/test/java/org/springframework/boot/jdbc/autoconfigure/TestJdbcConnectionDetails.java

@@ -18,6 +18,8 @@ package org.springframework.boot.jdbc.autoconfigure;
 
 import org.springframework.boot.jdbc.DatabaseDriver;
 
+import static org.assertj.core.api.Assertions.assertThat;
+
 /**
  * {@link JdbcConnectionDetails} used in tests.
  *
@@ -42,12 +44,16 @@ class TestJdbcConnectionDetails implements JdbcConnectionDetails {
 
 	@Override
 	public String getDriverClassName() {
-		return DatabaseDriver.POSTGRESQL.getDriverClassName();
+		String driverClassName = DatabaseDriver.POSTGRESQL.getDriverClassName();
+		assertThat(driverClassName).isNotNull();
+		return driverClassName;
 	}
 
 	@Override
 	public String getXaDataSourceClassName() {
-		return DatabaseDriver.POSTGRESQL.getXaDataSourceClassName();
+		String xaDataSourceClassName = DatabaseDriver.POSTGRESQL.getXaDataSourceClassName();
+		assertThat(xaDataSourceClassName).isNotNull();
+		return xaDataSourceClassName;
 	}
 
 }

module/spring-boot-jdbc/src/test/java/org/springframework/boot/jdbc/autoconfigure/TomcatJdbcConnectionDetailsBeanPostProcessorTests.java

@@ -19,9 +19,11 @@ package org.springframework.boot.jdbc.autoconfigure;
 import org.apache.tomcat.jdbc.pool.DataSource;
 import org.junit.jupiter.api.Test;
 
+import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.jdbc.DatabaseDriver;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
 
 /**
  * Tests for {@link TomcatJdbcConnectionDetailsBeanPostProcessor}.
@@ -33,13 +35,14 @@ import static org.assertj.core.api.Assertions.assertThat;
 class TomcatJdbcConnectionDetailsBeanPostProcessorTests {
 
 	@Test
+	@SuppressWarnings("unchecked")
 	void setUsernamePasswordUrlAndDriverClassName() {
 		DataSource dataSource = new DataSource();
 		dataSource.setUrl("will-be-overwritten");
 		dataSource.setUsername("will-be-overwritten");
 		dataSource.setPassword("will-be-overwritten");
 		dataSource.setDriverClassName("will-be-overwritten");
-		new TomcatJdbcConnectionDetailsBeanPostProcessor(null).processDataSource(dataSource,
+		new TomcatJdbcConnectionDetailsBeanPostProcessor(mock(ObjectProvider.class)).processDataSource(dataSource,
 				new TestJdbcConnectionDetails());
 		assertThat(dataSource.getUrl()).isEqualTo("jdbc:customdb://customdb.example.com:12345/database-1");
 		assertThat(dataSource.getUsername()).isEqualTo("user-1");

module/spring-boot-jdbc/src/test/java/org/springframework/boot/jdbc/autoconfigure/XADataSourceAutoConfigurationTests.java

@@ -21,6 +21,7 @@ import javax.sql.XADataSource;
 
 import com.ibm.db2.jcc.DB2XADataSource;
 import org.hsqldb.jdbc.pool.JDBCXADataSource;
+import org.jspecify.annotations.Nullable;
 import org.junit.jupiter.api.Test;
 import org.postgresql.xa.PGXADataSource;
 
@@ -161,7 +162,7 @@ class XADataSourceAutoConfigurationTests {
 
 	static class MockXADataSourceWrapper implements XADataSourceWrapper {
 
-		private XADataSource dataSource;
+		private @Nullable XADataSource dataSource;
 
 		@Override
 		public DataSource wrapDataSource(XADataSource dataSource) {
@@ -169,7 +170,7 @@ class XADataSourceAutoConfigurationTests {
 			return mock(DataSource.class);
 		}
 
-		XADataSource getXaDataSource() {
+		@Nullable XADataSource getXaDataSource() {
 			return this.dataSource;
 		}
 

module/spring-boot-jdbc/src/test/java/org/springframework/boot/jdbc/docker/compose/JdbcUrlBuilderTests.java

@@ -38,9 +38,10 @@ import static org.mockito.Mockito.mock;
  */
 class JdbcUrlBuilderTests {
 
-	private JdbcUrlBuilder builder = new JdbcUrlBuilder("mydb", 1234);
+	private final JdbcUrlBuilder builder = new JdbcUrlBuilder("mydb", 1234);
 
 	@Test
+	@SuppressWarnings("NullAway") // Test null check
 	void createWhenDriverProtocolIsNullThrowsException() {
 		assertThatIllegalArgumentException().isThrownBy(() -> new JdbcUrlBuilder(null, 123))
 			.withMessage("'driverProtocol' must not be null");
@@ -82,6 +83,7 @@ class JdbcUrlBuilderTests {
 	}
 
 	@Test
+	@SuppressWarnings("NullAway") // Test null check
 	void buildWhenServiceIsNullThrowsException() {
 		assertThatIllegalArgumentException().isThrownBy(() -> this.builder.build(null, "mydb"))
 			.withMessage("'service' must not be null");

module/spring-boot-jdbc/src/test/java/org/springframework/boot/jdbc/health/DataSourceHealthIndicatorTests.java

@@ -54,7 +54,9 @@ class DataSourceHealthIndicatorTests {
 	void init() {
 		EmbeddedDatabaseConnection db = EmbeddedDatabaseConnection.HSQLDB;
 		this.dataSource = new SingleConnectionDataSource(db.getUrl("testdb") + ";shutdown=true", "sa", "", false);
-		this.dataSource.setDriverClassName(db.getDriverClassName());
+		String driverClassName = db.getDriverClassName();
+		assertThat(driverClassName).isNotNull();
+		this.dataSource.setDriverClassName(driverClassName);
 	}
 
 	@AfterEach

module/spring-boot-jdbc/src/test/java/org/springframework/boot/jdbc/init/DataSourceScriptDatabaseInitializerTests.java

@@ -109,7 +109,9 @@ class DataSourceScriptDatabaseInitializerTests
 	}
 
 	private int numberOfRows(DataSource dataSource, String sql) {
-		return new JdbcTemplate(dataSource).queryForObject(sql, Integer.class);
+		Integer rows = new JdbcTemplate(dataSource).queryForObject(sql, Integer.class);
+		assertThat(rows).isNotNull();
+		return rows;
 	}
 
 	@Override

module/spring-boot-jdbc/src/test/java/org/springframework/boot/jdbc/metadata/AbstractDataSourcePoolMetadataTests.java

@@ -54,7 +54,7 @@ abstract class AbstractDataSourcePoolMetadataTests<D extends AbstractDataSourceP
 	void getPoolSizeNoConnection() {
 		// Make sure the pool is initialized
 		JdbcTemplate jdbcTemplate = new JdbcTemplate(getDataSourceMetadata().getDataSource());
-		jdbcTemplate.execute((ConnectionCallback<Void>) (connection) -> null);
+		jdbcTemplate.execute((ConnectionCallback<Object>) (connection) -> new Object());
 		assertThat(getDataSourceMetadata().getActive()).isZero();
 		assertThat(getDataSourceMetadata().getUsage()).isZero();
 	}
@@ -62,30 +62,30 @@ abstract class AbstractDataSourcePoolMetadataTests<D extends AbstractDataSourceP
 	@Test
 	void getPoolSizeOneConnection() {
 		JdbcTemplate jdbcTemplate = new JdbcTemplate(getDataSourceMetadata().getDataSource());
-		jdbcTemplate.execute((ConnectionCallback<Void>) (connection) -> {
+		jdbcTemplate.execute((ConnectionCallback<Object>) (connection) -> {
 			assertThat(getDataSourceMetadata().getActive()).isOne();
 			assertThat(getDataSourceMetadata().getUsage()).isEqualTo(0.5f);
-			return null;
+			return new Object();
 		});
 	}
 
 	@Test
 	void getIdle() {
 		JdbcTemplate jdbcTemplate = new JdbcTemplate(getDataSourceMetadata().getDataSource());
-		jdbcTemplate.execute((ConnectionCallback<Void>) (connection) -> null);
+		jdbcTemplate.execute((ConnectionCallback<Object>) (connection) -> new Object());
 		assertThat(getDataSourceMetadata().getIdle()).isOne();
 	}
 
 	@Test
 	void getPoolSizeTwoConnections() {
 		final JdbcTemplate jdbcTemplate = new JdbcTemplate(getDataSourceMetadata().getDataSource());
-		jdbcTemplate.execute((ConnectionCallback<Void>) (connection) -> {
+		jdbcTemplate.execute((ConnectionCallback<Object>) (connection) -> {
-			jdbcTemplate.execute((ConnectionCallback<Void>) (connection1) -> {
+			jdbcTemplate.execute((ConnectionCallback<Object>) (connection1) -> {
 				assertThat(getDataSourceMetadata().getActive()).isEqualTo(2);
 				assertThat(getDataSourceMetadata().getUsage()).isOne();
-				return null;
+				return new Object();
 			});
-			return null;
+			return new Object();
 		});
 	}
 

module/spring-boot-jdbc/src/test/java/org/springframework/boot/jdbc/metadata/CommonsDbcp2DataSourcePoolMetadataTests.java

@@ -19,6 +19,7 @@ package org.springframework.boot.jdbc.metadata;
 import java.time.Duration;
 
 import org.apache.commons.dbcp2.BasicDataSource;
+import org.jspecify.annotations.Nullable;
 import org.junit.jupiter.api.Test;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -42,7 +43,7 @@ class CommonsDbcp2DataSourcePoolMetadataTests
 	void getPoolUsageWithNoCurrent() {
 		CommonsDbcp2DataSourcePoolMetadata dsm = new CommonsDbcp2DataSourcePoolMetadata(createDataSource()) {
 			@Override
-			public Integer getActive() {
+			public @Nullable Integer getActive() {
 				return null;
 			}
 		};
@@ -53,7 +54,7 @@ class CommonsDbcp2DataSourcePoolMetadataTests
 	void getPoolUsageWithNoMax() {
 		CommonsDbcp2DataSourcePoolMetadata dsm = new CommonsDbcp2DataSourcePoolMetadata(createDataSource()) {
 			@Override
-			public Integer getMax() {
+			public @Nullable Integer getMax() {
 				return null;
 			}
 		};

module/spring-boot-jdbc/src/test/java/org/springframework/boot/jdbc/metadata/CompositeDataSourcePoolMetadataProviderTests.java

@@ -38,24 +38,31 @@ import static org.mockito.BDDMockito.given;
 class CompositeDataSourcePoolMetadataProviderTests {
 
 	@Mock
+	@SuppressWarnings("NullAway.Init")
 	private DataSourcePoolMetadataProvider firstProvider;
 
 	@Mock
+	@SuppressWarnings("NullAway.Init")
 	private DataSourcePoolMetadata first;
 
 	@Mock
+	@SuppressWarnings("NullAway.Init")
 	private DataSource firstDataSource;
 
 	@Mock
+	@SuppressWarnings("NullAway.Init")
 	private DataSourcePoolMetadataProvider secondProvider;
 
 	@Mock
+	@SuppressWarnings("NullAway.Init")
 	private DataSourcePoolMetadata second;
 
 	@Mock
+	@SuppressWarnings("NullAway.Init")
 	private DataSource secondDataSource;
 
 	@Mock
+	@SuppressWarnings("NullAway.Init")
 	private DataSource unknownDataSource;
 
 	@BeforeEach