Improve LDAP auto-configuration conditions

At present, auto-configuration of `LdapContextSource` is conditional on
presence of a `ContextSource` bean. However, there are valid use cases
which require multiple `ContextSource` bean, for instance
`PooledContextSource`. With the current arrangement, the
auto-configuration of `LdapContextSource` will back off if user provides
a `PooledContextSource` bean, while it would still be reasonable to
reuse the auto-configured `LdapContextSource`.

This commit improves `LdapContextSource` factory method return value and
condition to back off only if users actually provide a
`LdapContextSource` bean themselves.

See gh-13143

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/ldap/LdapAutoConfiguration.java

@@ -53,7 +53,7 @@ public class LdapAutoConfiguration {
 
 	@Bean
 	@ConditionalOnMissingBean
-	public ContextSource ldapContextSource() {
+	public LdapContextSource ldapContextSource() {
 		LdapContextSource source = new LdapContextSource();
 		source.setUserDn(this.properties.getUsername());
 		source.setPassword(this.properties.getPassword());

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/ldap/embedded/EmbeddedLdapAutoConfiguration.java

@@ -58,7 +58,6 @@ import org.springframework.core.env.MutablePropertySources;
 import org.springframework.core.env.PropertySource;
 import org.springframework.core.io.Resource;
 import org.springframework.core.type.AnnotatedTypeMetadata;
-import org.springframework.ldap.core.ContextSource;
 import org.springframework.ldap.core.support.LdapContextSource;
 import org.springframework.util.StringUtils;
 
@@ -101,7 +100,7 @@ public class EmbeddedLdapAutoConfiguration {
 	@Bean
 	@DependsOn("directoryServer")
 	@ConditionalOnMissingBean
-	public ContextSource ldapContextSource() {
+	public LdapContextSource ldapContextSource() {
 		LdapContextSource source = new LdapContextSource();
 		if (hasCredentials(this.embeddedProperties.getCredential())) {
 			source.setUserDn(this.embeddedProperties.getCredential().getUsername());

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/ldap/LdapAutoConfigurationTests.java

@@ -20,9 +20,13 @@ import org.junit.Test;
 
 import org.springframework.boot.autoconfigure.AutoConfigurations;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
 import org.springframework.ldap.core.ContextSource;
 import org.springframework.ldap.core.LdapTemplate;
 import org.springframework.ldap.core.support.LdapContextSource;
+import org.springframework.ldap.pool2.factory.PoolConfig;
+import org.springframework.ldap.pool2.factory.PooledContextSource;
 import org.springframework.test.util.ReflectionTestUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -54,7 +58,8 @@ public class LdapAutoConfigurationTests {
 	public void contextSourceWithSingleUrl() {
 		this.contextRunner.withPropertyValues("spring.ldap.urls:ldap://localhost:123")
 				.run((context) -> {
-					ContextSource contextSource = context.getBean(ContextSource.class);
+					ContextSource contextSource = context
+							.getBean(LdapContextSource.class);
 					String[] urls = (String[]) ReflectionTestUtils.getField(contextSource,
 							"urls");
 					assertThat(urls).containsExactly("ldap://localhost:123");
@@ -67,7 +72,8 @@ public class LdapAutoConfigurationTests {
 				.withPropertyValues(
 						"spring.ldap.urls:ldap://localhost:123,ldap://mycompany:123")
 				.run((context) -> {
-					ContextSource contextSource = context.getBean(ContextSource.class);
+					ContextSource contextSource = context
+							.getBean(LdapContextSource.class);
 					LdapProperties ldapProperties = context.getBean(LdapProperties.class);
 					String[] urls = (String[]) ReflectionTestUtils.getField(contextSource,
 							"urls");
@@ -104,4 +110,32 @@ public class LdapAutoConfigurationTests {
 				.run(context -> assertThat(context).hasSingleBean(LdapTemplate.class));
 	}
 
+	@Test
+	public void contextSourceWithUserProvidedPooledContextSource() {
+		this.contextRunner.withUserConfiguration(PooledContextSourceConfig.class)
+				.run((context) -> {
+					LdapContextSource contextSource = context
+							.getBean(LdapContextSource.class);
+					String[] urls = (String[]) ReflectionTestUtils.getField(contextSource,
+							"urls");
+					assertThat(urls).containsExactly("ldap://localhost:389");
+					assertThat(contextSource.isAnonymousReadOnly()).isFalse();
+					context.getBean(PooledContextSource.class);
+				});
+	}
+
+	@Configuration
+	static class PooledContextSourceConfig {
+
+		@Bean
+		public PooledContextSource pooledContextSource(
+				LdapContextSource ldapContextSource) {
+			PooledContextSource pooledContextSource = new PooledContextSource(
+					new PoolConfig());
+			pooledContextSource.setContextSource(ldapContextSource);
+			return pooledContextSource;
+		}
+
+	}
+
 }