Merge pull request #19328 from filiphr

* pr/19328:
  Polish "Detect DirContextAuthenticationStrategy bean"
  Detect DirContextAuthenticationStrategy bean

Closes gh-19328

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

@@ -18,6 +18,7 @@ package org.springframework.boot.autoconfigure.ldap;
 
 import java.util.Collections;
 
+import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
@@ -29,6 +30,7 @@ import org.springframework.core.env.Environment;
 import org.springframework.ldap.core.ContextSource;
 import org.springframework.ldap.core.LdapOperations;
 import org.springframework.ldap.core.LdapTemplate;
+import org.springframework.ldap.core.support.DirContextAuthenticationStrategy;
 import org.springframework.ldap.core.support.LdapContextSource;
 
 /**
@@ -45,8 +47,10 @@ public class LdapAutoConfiguration {
 
 	@Bean
 	@ConditionalOnMissingBean
-	public LdapContextSource ldapContextSource(LdapProperties properties, Environment environment) {
+	public LdapContextSource ldapContextSource(LdapProperties properties, Environment environment,
+			ObjectProvider<DirContextAuthenticationStrategy> dirContextAuthenticationStrategy) {
 		LdapContextSource source = new LdapContextSource();
+		dirContextAuthenticationStrategy.ifUnique(source::setAuthenticationStrategy);
 		PropertyMapper propertyMapper = PropertyMapper.get().alwaysApplyingWhenNonNull();
 		propertyMapper.from(properties.getUsername()).to(source::setUserDn);
 		propertyMapper.from(properties.getPassword()).to(source::setPassword);

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

@@ -24,11 +24,15 @@ import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Primary;
 import org.springframework.ldap.core.LdapTemplate;
+import org.springframework.ldap.core.support.DirContextAuthenticationStrategy;
 import org.springframework.ldap.core.support.LdapContextSource;
+import org.springframework.ldap.core.support.SimpleDirContextAuthenticationStrategy;
 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;
+import static org.mockito.Mockito.mock;
 
 /**
  * Tests for {@link LdapAutoConfiguration}.
@@ -113,6 +117,30 @@ class LdapAutoConfigurationTests {
 		});
 	}
 
+	@Test
+	void contextSourceWithCustomUniqueDirContextAuthenticationStrategy() {
+		this.contextRunner.withUserConfiguration(CustomDirContextAuthenticationStrategy.class).run((context) -> {
+			assertThat(context).hasSingleBean(DirContextAuthenticationStrategy.class);
+			LdapContextSource contextSource = context.getBean(LdapContextSource.class);
+			assertThat(ReflectionTestUtils.getField(contextSource, "authenticationStrategy"))
+					.isSameAs(context.getBean("customDirContextAuthenticationStrategy"));
+		});
+	}
+
+	@Test
+	void contextSourceWithCustomNonUniqueDirContextAuthenticationStrategy() {
+		this.contextRunner.withUserConfiguration(CustomDirContextAuthenticationStrategy.class,
+				AnotherCustomDirContextAuthenticationStrategy.class).run((context) -> {
+					assertThat(context).hasBean("customDirContextAuthenticationStrategy")
+							.hasBean("anotherCustomDirContextAuthenticationStrategy");
+					LdapContextSource contextSource = context.getBean(LdapContextSource.class);
+					assertThat(ReflectionTestUtils.getField(contextSource, "authenticationStrategy"))
+							.isNotSameAs(context.getBean("customDirContextAuthenticationStrategy"))
+							.isNotSameAs(context.getBean("anotherCustomDirContextAuthenticationStrategy"))
+							.isInstanceOf(SimpleDirContextAuthenticationStrategy.class);
+				});
+	}
+
 	@Configuration(proxyBeanMethods = false)
 	static class PooledContextSourceConfig {
 
@@ -126,4 +154,24 @@ class LdapAutoConfigurationTests {
 
 	}
 
+	@Configuration(proxyBeanMethods = false)
+	static class CustomDirContextAuthenticationStrategy {
+
+		@Bean
+		DirContextAuthenticationStrategy customDirContextAuthenticationStrategy() {
+			return mock(DirContextAuthenticationStrategy.class);
+		}
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	static class AnotherCustomDirContextAuthenticationStrategy {
+
+		@Bean
+		DirContextAuthenticationStrategy anotherCustomDirContextAuthenticationStrategy() {
+			return mock(DirContextAuthenticationStrategy.class);
+		}
+
+	}
+
 }

spring-boot-project/spring-boot-docs/src/main/asciidoc/spring-boot-features.adoc

@@ -4445,6 +4445,7 @@ To connect to an LDAP server, make sure you declare a dependency on the `spring-
 If you need to customize connection settings, you can use the `spring.ldap.base` and `spring.ldap.base-environment` properties.
 
 An `LdapContextSource` is auto-configured based on these settings.
+If a `DirContextAuthenticationStrategy` bean is available, it is associated to the auto-configured `LdapContextSource`.
 If you need to customize it, for instance to use a `PooledContextSource`, you can still inject the auto-configured `LdapContextSource`.
 Make sure to flag your customized `ContextSource` as `@Primary` so that the auto-configured `LdapTemplate` uses it.