Improve null-safety of core/spring-boot-docker-compose

See gh-46926

core/spring-boot-docker-compose/src/main/java/org/springframework/boot/docker/compose/core/DefaultRunningService.java

@@ -88,7 +88,7 @@ class DefaultRunningService implements RunningService, OriginProvider {
 	}
 
 	@Override
-	public Map<String, String> env() {
+	public Map<String, @Nullable String> env() {
 		return this.env.asMap();
 	}
 

core/spring-boot-docker-compose/src/main/java/org/springframework/boot/docker/compose/core/DockerCli.java

@@ -44,7 +44,7 @@ import org.springframework.util.CollectionUtils;
  */
 class DockerCli {
 
-	private static final Map<File, DockerCommands> dockerCommandsCache = new HashMap<>();
+	private static final Map<@Nullable File, DockerCommands> dockerCommandsCache = new HashMap<>();
 
 	private static final Log logger = LogFactory.getLog(DockerCli.class);
 

core/spring-boot-docker-compose/src/main/java/org/springframework/boot/docker/compose/core/DockerEnv.java

@@ -34,7 +34,7 @@ import org.springframework.util.CollectionUtils;
  */
 class DockerEnv {
 
-	private final Map<String, String> map;
+	private final Map<String, @Nullable String> map;
 
 	/**
 	 * Create a new {@link DockerEnv} instance.
@@ -44,11 +44,11 @@ class DockerEnv {
 		this.map = parse(env);
 	}
 
-	private Map<String, String> parse(List<String> env) {
+	private Map<String, @Nullable String> parse(List<String> env) {
 		if (CollectionUtils.isEmpty(env)) {
 			return Collections.emptyMap();
 		}
-		Map<String, String> result = new LinkedHashMap<>();
+		Map<String, @Nullable String> result = new LinkedHashMap<>();
 		env.stream().map(this::parseEntry).forEach((entry) -> result.put(entry.key(), entry.value()));
 		return Collections.unmodifiableMap(result);
 	}
@@ -67,7 +67,7 @@ class DockerEnv {
 	 * Return the env as a {@link Map}.
 	 * @return the env as a map
 	 */
-	Map<String, String> asMap() {
+	Map<String, @Nullable String> asMap() {
 		return this.map;
 	}
 

core/spring-boot-docker-compose/src/main/java/org/springframework/boot/docker/compose/core/RunningService.java

@@ -58,7 +58,7 @@ public interface RunningService {
 	 * Return the environment defined for the service.
 	 * @return the service env
 	 */
-	Map<String, String> env();
+	Map<String, @Nullable String> env();
 
 	/**
 	 * Return the labels attached to the service.

module/spring-boot-activemq/src/main/java/org/springframework/boot/activemq/docker/compose/ActiveMQClassicEnvironment.java

@@ -32,7 +32,7 @@ class ActiveMQClassicEnvironment {
 
 	private final @Nullable String password;
 
-	ActiveMQClassicEnvironment(Map<String, String> env) {
+	ActiveMQClassicEnvironment(Map<String, @Nullable String> env) {
 		this.user = env.get("ACTIVEMQ_CONNECTION_USER");
 		this.password = env.get("ACTIVEMQ_CONNECTION_PASSWORD");
 	}

module/spring-boot-activemq/src/main/java/org/springframework/boot/activemq/docker/compose/ActiveMQEnvironment.java

@@ -31,7 +31,7 @@ class ActiveMQEnvironment {
 
 	private final @Nullable String password;
 
-	ActiveMQEnvironment(Map<String, String> env) {
+	ActiveMQEnvironment(Map<String, @Nullable String> env) {
 		this.user = env.get("ACTIVEMQ_USERNAME");
 		this.password = env.get("ACTIVEMQ_PASSWORD");
 	}

module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/docker/compose/RabbitEnvironment.java

@@ -18,6 +18,8 @@ package org.springframework.boot.amqp.docker.compose;
 
 import java.util.Map;
 
+import org.jspecify.annotations.Nullable;
+
 /**
  * RabbitMQ environment details.
  *
@@ -32,7 +34,7 @@ class RabbitEnvironment {
 
 	private final String password;
 
-	RabbitEnvironment(Map<String, String> env) {
+	RabbitEnvironment(Map<String, @Nullable String> env) {
 		this.username = env.getOrDefault("RABBITMQ_DEFAULT_USER", env.getOrDefault("RABBITMQ_USERNAME", "guest"));
 		this.password = env.getOrDefault("RABBITMQ_DEFAULT_PASS", env.getOrDefault("RABBITMQ_PASSWORD", "guest"));
 	}

module/spring-boot-artemis/src/main/java/org/springframework/boot/artemis/docker/compose/ArtemisEnvironment.java

@@ -32,7 +32,7 @@ class ArtemisEnvironment {
 
 	private final @Nullable String password;
 
-	ArtemisEnvironment(Map<String, String> env) {
+	ArtemisEnvironment(Map<String, @Nullable String> env) {
 		this.user = env.get("ARTEMIS_USER");
 		this.password = env.get("ARTEMIS_PASSWORD");
 	}

module/spring-boot-cassandra/src/main/java/org/springframework/boot/cassandra/docker/compose/CassandraEnvironment.java

@@ -18,6 +18,8 @@ package org.springframework.boot.cassandra.docker.compose;
 
 import java.util.Map;
 
+import org.jspecify.annotations.Nullable;
+
 /**
  * Cassandra environment details.
  *
@@ -27,7 +29,7 @@ class CassandraEnvironment {
 
 	private final String datacenter;
 
-	CassandraEnvironment(Map<String, String> env) {
+	CassandraEnvironment(Map<String, @Nullable String> env) {
 		this.datacenter = env.getOrDefault("CASSANDRA_DC", env.getOrDefault("CASSANDRA_DATACENTER", "datacenter1"));
 	}
 

module/spring-boot-elasticsearch/src/main/java/org/springframework/boot/elasticsearch/docker/compose/ElasticsearchEnvironment.java

@@ -33,7 +33,7 @@ class ElasticsearchEnvironment {
 
 	private final @Nullable String password;
 
-	ElasticsearchEnvironment(Map<String, String> env) {
+	ElasticsearchEnvironment(Map<String, @Nullable String> env) {
 		Assert.state(!env.containsKey("ELASTIC_PASSWORD_FILE"), "ELASTIC_PASSWORD_FILE is not supported");
 		this.password = env.get("ELASTIC_PASSWORD");
 	}

module/spring-boot-hazelcast/src/main/java/org/springframework/boot/hazelcast/docker/compose/HazelcastEnvironment.java

@@ -29,7 +29,7 @@ class HazelcastEnvironment {
 
 	private final @Nullable String clusterName;
 
-	HazelcastEnvironment(Map<String, String> env) {
+	HazelcastEnvironment(Map<String, @Nullable String> env) {
 		this.clusterName = env.get("HZ_CLUSTERNAME");
 	}
 

module/spring-boot-jdbc/src/main/java/org/springframework/boot/jdbc/docker/compose/ClickHouseEnvironment.java

@@ -18,6 +18,8 @@ package org.springframework.boot.jdbc.docker.compose;
 
 import java.util.Map;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
@@ -34,13 +36,13 @@ class ClickHouseEnvironment {
 
 	private final String database;
 
-	ClickHouseEnvironment(Map<String, String> env) {
+	ClickHouseEnvironment(Map<String, @Nullable String> env) {
 		this.username = env.getOrDefault("CLICKHOUSE_USER", "default");
 		this.password = extractPassword(env);
 		this.database = env.getOrDefault("CLICKHOUSE_DB", "default");
 	}
 
-	private String extractPassword(Map<String, String> env) {
+	private String extractPassword(Map<String, @Nullable String> env) {
 		boolean allowEmpty = env.containsKey("ALLOW_EMPTY_PASSWORD");
 		String password = env.get("CLICKHOUSE_PASSWORD");
 		Assert.state(StringUtils.hasLength(password) || allowEmpty, "No ClickHouse password found");

module/spring-boot-jdbc/src/main/java/org/springframework/boot/jdbc/docker/compose/MariaDbEnvironment.java

@@ -18,6 +18,8 @@ package org.springframework.boot.jdbc.docker.compose;
 
 import java.util.Map;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
@@ -37,18 +39,18 @@ class MariaDbEnvironment {
 
 	private final String database;
 
-	MariaDbEnvironment(Map<String, String> env) {
+	MariaDbEnvironment(Map<String, @Nullable String> env) {
 		this.username = extractUsername(env);
 		this.password = extractPassword(env);
 		this.database = extractDatabase(env);
 	}
 
-	private String extractUsername(Map<String, String> env) {
+	private String extractUsername(Map<String, @Nullable String> env) {
 		String user = env.get("MARIADB_USER");
 		return (user != null) ? user : env.getOrDefault("MYSQL_USER", "root");
 	}
 
-	private String extractPassword(Map<String, String> env) {
+	private String extractPassword(Map<String, @Nullable String> env) {
 		Assert.state(!env.containsKey("MARIADB_RANDOM_ROOT_PASSWORD"), "MARIADB_RANDOM_ROOT_PASSWORD is not supported");
 		Assert.state(!env.containsKey("MYSQL_RANDOM_ROOT_PASSWORD"), "MYSQL_RANDOM_ROOT_PASSWORD is not supported");
 		Assert.state(!env.containsKey("MARIADB_ROOT_PASSWORD_HASH"), "MARIADB_ROOT_PASSWORD_HASH is not supported");
@@ -62,7 +64,7 @@ class MariaDbEnvironment {
 		return (password != null) ? password : "";
 	}
 
-	private String extractDatabase(Map<String, String> env) {
+	private String extractDatabase(Map<String, @Nullable String> env) {
 		String database = env.get("MARIADB_DATABASE");
 		database = (database != null) ? database : env.get("MYSQL_DATABASE");
 		Assert.state(database != null, "No MARIADB_DATABASE defined");

module/spring-boot-jdbc/src/main/java/org/springframework/boot/jdbc/docker/compose/MySqlEnvironment.java

@@ -18,6 +18,8 @@ package org.springframework.boot.jdbc.docker.compose;
 
 import java.util.Map;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
@@ -37,13 +39,13 @@ class MySqlEnvironment {
 
 	private final String database;
 
-	MySqlEnvironment(Map<String, String> env) {
+	MySqlEnvironment(Map<String, @Nullable String> env) {
 		this.username = env.getOrDefault("MYSQL_USER", "root");
 		this.password = extractPassword(env);
 		this.database = extractDatabase(env);
 	}
 
-	private String extractPassword(Map<String, String> env) {
+	private String extractPassword(Map<String, @Nullable String> env) {
 		Assert.state(!env.containsKey("MYSQL_RANDOM_ROOT_PASSWORD"), "MYSQL_RANDOM_ROOT_PASSWORD is not supported");
 		boolean allowEmpty = env.containsKey("MYSQL_ALLOW_EMPTY_PASSWORD") || env.containsKey("ALLOW_EMPTY_PASSWORD");
 		String password = env.get("MYSQL_PASSWORD");
@@ -52,7 +54,7 @@ class MySqlEnvironment {
 		return (password != null) ? password : "";
 	}
 
-	private String extractDatabase(Map<String, String> env) {
+	private String extractDatabase(Map<String, @Nullable String> env) {
 		String database = env.get("MYSQL_DATABASE");
 		Assert.state(database != null, "No MYSQL_DATABASE defined");
 		return database;

module/spring-boot-jdbc/src/main/java/org/springframework/boot/jdbc/docker/compose/OracleEnvironment.java

@@ -18,6 +18,8 @@ package org.springframework.boot.jdbc.docker.compose;
 
 import java.util.Map;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
@@ -34,13 +36,13 @@ class OracleEnvironment {
 
 	private final String database;
 
-	OracleEnvironment(Map<String, String> env, String defaultDatabase) {
+	OracleEnvironment(Map<String, @Nullable String> env, String defaultDatabase) {
 		this.username = env.getOrDefault("APP_USER", "system");
 		this.password = extractPassword(env);
 		this.database = env.getOrDefault("ORACLE_DATABASE", defaultDatabase);
 	}
 
-	private String extractPassword(Map<String, String> env) {
+	private String extractPassword(Map<String, @Nullable String> env) {
 		if (env.containsKey("APP_USER")) {
 			String password = env.get("APP_USER_PASSWORD");
 			Assert.state(StringUtils.hasLength(password), "No Oracle app password found");

module/spring-boot-jdbc/src/main/java/org/springframework/boot/jdbc/docker/compose/PostgresEnvironment.java

@@ -49,13 +49,13 @@ class PostgresEnvironment {
 
 	private final String database;
 
-	PostgresEnvironment(Map<String, String> env) {
+	PostgresEnvironment(Map<String, @Nullable String> env) {
 		this.username = extract(env, USERNAME_KEYS, DEFAULT_USERNAME);
 		this.password = extractPassword(env);
 		this.database = extract(env, DATABASE_KEYS, this.username);
 	}
 
-	private String extract(Map<String, String> env, String[] keys, String defaultValue) {
+	private String extract(Map<String, @Nullable String> env, String[] keys, String defaultValue) {
 		for (String key : keys) {
 			if (env.containsKey(key)) {
 				return env.get(key);
@@ -64,7 +64,7 @@ class PostgresEnvironment {
 		return defaultValue;
 	}
 
-	private @Nullable String extractPassword(Map<String, String> env) {
+	private @Nullable String extractPassword(Map<String, @Nullable String> env) {
 		if (isUsingTrustHostAuthMethod(env)) {
 			return null;
 		}
@@ -74,7 +74,7 @@ class PostgresEnvironment {
 		return (password != null) ? password : "";
 	}
 
-	private boolean isUsingTrustHostAuthMethod(Map<String, String> env) {
+	private boolean isUsingTrustHostAuthMethod(Map<String, @Nullable String> env) {
 		String hostAuthMethod = env.get("POSTGRES_HOST_AUTH_METHOD");
 		return "trust".equals(hostAuthMethod);
 	}

module/spring-boot-jdbc/src/main/java/org/springframework/boot/jdbc/docker/compose/SqlServerEnvironment.java

@@ -18,6 +18,8 @@ package org.springframework.boot.jdbc.docker.compose;
 
 import java.util.Map;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
@@ -32,11 +34,11 @@ class SqlServerEnvironment {
 
 	private final String password;
 
-	SqlServerEnvironment(Map<String, String> env) {
+	SqlServerEnvironment(Map<String, @Nullable String> env) {
 		this.password = extractPassword(env);
 	}
 
-	private String extractPassword(Map<String, String> env) {
+	private String extractPassword(Map<String, @Nullable String> env) {
 		String password = env.get("MSSQL_SA_PASSWORD");
 		password = (password != null) ? password : env.get("SA_PASSWORD");
 		Assert.state(StringUtils.hasLength(password), "No MSSQL password found");

module/spring-boot-ldap/src/main/java/org/springframework/boot/ldap/docker/compose/LLdapDockerComposeConnectionDetailsFactory.java

@@ -18,6 +18,8 @@ package org.springframework.boot.ldap.docker.compose;
 
 import java.util.Map;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.boot.docker.compose.core.RunningService;
 import org.springframework.boot.docker.compose.service.connection.DockerComposeConnectionDetailsFactory;
 import org.springframework.boot.docker.compose.service.connection.DockerComposeConnectionSource;
@@ -56,7 +58,7 @@ class LLdapDockerComposeConnectionDetailsFactory extends DockerComposeConnection
 
 		LLdapDockerComposeConnectionDetails(RunningService service) {
 			super(service);
-			Map<String, String> env = service.env();
+			Map<String, @Nullable String> env = service.env();
 			boolean usesTls = Boolean.parseBoolean(env.getOrDefault("LLDAP_LDAPS_OPTIONS__ENABLED", "false"));
 			String ldapPort = usesTls ? env.getOrDefault("LLDAP_LDAPS_OPTIONS__PORT", "6360")
 					: env.getOrDefault("LLDAP_LDAP_PORT", "3890");

module/spring-boot-ldap/src/main/java/org/springframework/boot/ldap/docker/compose/OpenLdapDockerComposeConnectionDetailsFactory.java

@@ -20,6 +20,8 @@ import java.util.Arrays;
 import java.util.Map;
 import java.util.stream.Collectors;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.boot.docker.compose.core.RunningService;
 import org.springframework.boot.docker.compose.service.connection.DockerComposeConnectionDetailsFactory;
 import org.springframework.boot.docker.compose.service.connection.DockerComposeConnectionSource;
@@ -59,7 +61,7 @@ class OpenLdapDockerComposeConnectionDetailsFactory
 
 		OpenLdapDockerComposeConnectionDetails(RunningService service) {
 			super(service);
-			Map<String, String> env = service.env();
+			Map<String, @Nullable String> env = service.env();
 			boolean usesTls = Boolean.parseBoolean(env.getOrDefault("LDAP_TLS", "true"));
 			String ldapPort = usesTls ? env.getOrDefault("LDAPS_PORT", "636") : env.getOrDefault("LDAP_PORT", "389");
 			this.urls = new String[] { "%s://%s:%d".formatted(usesTls ? "ldaps" : "ldap", service.host(),

module/spring-boot-mongodb/src/main/java/org/springframework/boot/mongodb/docker/compose/MongoEnvironment.java

@@ -38,7 +38,7 @@ class MongoEnvironment {
 
 	private final @Nullable String database;
 
-	MongoEnvironment(Map<String, String> env) {
+	MongoEnvironment(Map<String, @Nullable String> env) {
 		Assert.state(!env.containsKey("MONGO_INITDB_ROOT_USERNAME_FILE"),
 				"MONGO_INITDB_ROOT_USERNAME_FILE is not supported");
 		Assert.state(!env.containsKey("MONGO_INITDB_ROOT_PASSWORD_FILE"),

module/spring-boot-neo4j/src/main/java/org/springframework/boot/neo4j/docker/compose/Neo4jEnvironment.java

@@ -32,7 +32,7 @@ class Neo4jEnvironment {
 
 	private final @Nullable AuthToken authToken;
 
-	Neo4jEnvironment(Map<String, String> env) {
+	Neo4jEnvironment(Map<String, @Nullable String> env) {
 		AuthToken authToken = parse(env.get("NEO4J_AUTH"));
 		if (authToken == null && env.containsKey("NEO4J_PASSWORD")) {
 			authToken = parse("neo4j/" + env.get("NEO4J_PASSWORD"));

module/spring-boot-r2dbc/src/main/java/org/springframework/boot/r2dbc/docker/compose/ClickHouseEnvironment.java

@@ -18,6 +18,8 @@ package org.springframework.boot.r2dbc.docker.compose;
 
 import java.util.Map;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
@@ -34,13 +36,13 @@ class ClickHouseEnvironment {
 
 	private final String database;
 
-	ClickHouseEnvironment(Map<String, String> env) {
+	ClickHouseEnvironment(Map<String, @Nullable String> env) {
 		this.username = env.getOrDefault("CLICKHOUSE_USER", "default");
 		this.password = extractPassword(env);
 		this.database = env.getOrDefault("CLICKHOUSE_DB", "default");
 	}
 
-	private String extractPassword(Map<String, String> env) {
+	private String extractPassword(Map<String, @Nullable String> env) {
 		boolean allowEmpty = env.containsKey("ALLOW_EMPTY_PASSWORD");
 		String password = env.get("CLICKHOUSE_PASSWORD");
 		Assert.state(StringUtils.hasLength(password) || allowEmpty, "No ClickHouse password found");

module/spring-boot-r2dbc/src/main/java/org/springframework/boot/r2dbc/docker/compose/MariaDbEnvironment.java

@@ -18,6 +18,8 @@ package org.springframework.boot.r2dbc.docker.compose;
 
 import java.util.Map;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
@@ -37,18 +39,18 @@ class MariaDbEnvironment {
 
 	private final String database;
 
-	MariaDbEnvironment(Map<String, String> env) {
+	MariaDbEnvironment(Map<String, @Nullable String> env) {
 		this.username = extractUsername(env);
 		this.password = extractPassword(env);
 		this.database = extractDatabase(env);
 	}
 
-	private String extractUsername(Map<String, String> env) {
+	private String extractUsername(Map<String, @Nullable String> env) {
 		String user = env.get("MARIADB_USER");
 		return (user != null) ? user : env.getOrDefault("MYSQL_USER", "root");
 	}
 
-	private String extractPassword(Map<String, String> env) {
+	private String extractPassword(Map<String, @Nullable String> env) {
 		Assert.state(!env.containsKey("MARIADB_RANDOM_ROOT_PASSWORD"), "MARIADB_RANDOM_ROOT_PASSWORD is not supported");
 		Assert.state(!env.containsKey("MYSQL_RANDOM_ROOT_PASSWORD"), "MYSQL_RANDOM_ROOT_PASSWORD is not supported");
 		Assert.state(!env.containsKey("MARIADB_ROOT_PASSWORD_HASH"), "MARIADB_ROOT_PASSWORD_HASH is not supported");
@@ -62,7 +64,7 @@ class MariaDbEnvironment {
 		return (password != null) ? password : "";
 	}
 
-	private String extractDatabase(Map<String, String> env) {
+	private String extractDatabase(Map<String, @Nullable String> env) {
 		String database = env.get("MARIADB_DATABASE");
 		database = (database != null) ? database : env.get("MYSQL_DATABASE");
 		Assert.state(database != null, "No MARIADB_DATABASE defined");

module/spring-boot-r2dbc/src/main/java/org/springframework/boot/r2dbc/docker/compose/MySqlEnvironment.java

@@ -18,6 +18,8 @@ package org.springframework.boot.r2dbc.docker.compose;
 
 import java.util.Map;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
@@ -37,13 +39,13 @@ class MySqlEnvironment {
 
 	private final String database;
 
-	MySqlEnvironment(Map<String, String> env) {
+	MySqlEnvironment(Map<String, @Nullable String> env) {
 		this.username = env.getOrDefault("MYSQL_USER", "root");
 		this.password = extractPassword(env);
 		this.database = extractDatabase(env);
 	}
 
-	private String extractPassword(Map<String, String> env) {
+	private String extractPassword(Map<String, @Nullable String> env) {
 		Assert.state(!env.containsKey("MYSQL_RANDOM_ROOT_PASSWORD"), "MYSQL_RANDOM_ROOT_PASSWORD is not supported");
 		boolean allowEmpty = env.containsKey("MYSQL_ALLOW_EMPTY_PASSWORD") || env.containsKey("ALLOW_EMPTY_PASSWORD");
 		String password = env.get("MYSQL_PASSWORD");
@@ -52,7 +54,7 @@ class MySqlEnvironment {
 		return (password != null) ? password : "";
 	}
 
-	private String extractDatabase(Map<String, String> env) {
+	private String extractDatabase(Map<String, @Nullable String> env) {
 		String database = env.get("MYSQL_DATABASE");
 		Assert.state(database != null, "No MYSQL_DATABASE defined");
 		return database;

module/spring-boot-r2dbc/src/main/java/org/springframework/boot/r2dbc/docker/compose/OracleEnvironment.java

@@ -18,6 +18,8 @@ package org.springframework.boot.r2dbc.docker.compose;
 
 import java.util.Map;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
@@ -34,13 +36,13 @@ class OracleEnvironment {
 
 	private final String database;
 
-	OracleEnvironment(Map<String, String> env, String defaultDatabase) {
+	OracleEnvironment(Map<String, @Nullable String> env, String defaultDatabase) {
 		this.username = env.getOrDefault("APP_USER", "system");
 		this.password = extractPassword(env);
 		this.database = env.getOrDefault("ORACLE_DATABASE", defaultDatabase);
 	}
 
-	private String extractPassword(Map<String, String> env) {
+	private String extractPassword(Map<String, @Nullable String> env) {
 		if (env.containsKey("APP_USER")) {
 			String password = env.get("APP_USER_PASSWORD");
 			Assert.state(StringUtils.hasLength(password), "No Oracle app password found");

module/spring-boot-r2dbc/src/main/java/org/springframework/boot/r2dbc/docker/compose/PostgresEnvironment.java

@@ -49,13 +49,13 @@ class PostgresEnvironment {
 
 	private final String database;
 
-	PostgresEnvironment(Map<String, String> env) {
+	PostgresEnvironment(Map<String, @Nullable String> env) {
 		this.username = extract(env, USERNAME_KEYS, DEFAULT_USERNAME);
 		this.password = extractPassword(env);
 		this.database = extract(env, DATABASE_KEYS, this.username);
 	}
 
-	private String extract(Map<String, String> env, String[] keys, String defaultValue) {
+	private String extract(Map<String, @Nullable String> env, String[] keys, String defaultValue) {
 		for (String key : keys) {
 			if (env.containsKey(key)) {
 				return env.get(key);
@@ -64,7 +64,7 @@ class PostgresEnvironment {
 		return defaultValue;
 	}
 
-	private @Nullable String extractPassword(Map<String, String> env) {
+	private @Nullable String extractPassword(Map<String, @Nullable String> env) {
 		if (isUsingTrustHostAuthMethod(env)) {
 			return null;
 		}
@@ -74,7 +74,7 @@ class PostgresEnvironment {
 		return (password != null) ? password : "";
 	}
 
-	private boolean isUsingTrustHostAuthMethod(Map<String, String> env) {
+	private boolean isUsingTrustHostAuthMethod(Map<String, @Nullable String> env) {
 		String hostAuthMethod = env.get("POSTGRES_HOST_AUTH_METHOD");
 		return "trust".equals(hostAuthMethod);
 	}

module/spring-boot-r2dbc/src/main/java/org/springframework/boot/r2dbc/docker/compose/SqlServerEnvironment.java

@@ -18,6 +18,8 @@ package org.springframework.boot.r2dbc.docker.compose;
 
 import java.util.Map;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
@@ -32,11 +34,11 @@ class SqlServerEnvironment {
 
 	private final String password;
 
-	SqlServerEnvironment(Map<String, String> env) {
+	SqlServerEnvironment(Map<String, @Nullable String> env) {
 		this.password = extractPassword(env);
 	}
 
-	private String extractPassword(Map<String, String> env) {
+	private String extractPassword(Map<String, @Nullable String> env) {
 		String password = env.get("MSSQL_SA_PASSWORD");
 		password = (password != null) ? password : env.get("SA_PASSWORD");
 		Assert.state(StringUtils.hasLength(password), "No MSSQL password found");