Use alwaysApplyingWhenNonNull PropertyMapper to set the values in the LdapContextSource

The userDn and password in LdapContextSource are not nullable.
The default values for userDn and password in LdapProperties are null.
When the values are set to null there will eventually be a NullPointerException
during AbstractContextSource#setupAuthenticatedEnvironment since HashTable doesn't allow
null for values

Author: filiphr

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

@@ -22,6 +22,7 @@
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.boot.context.properties.PropertyMapper;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.env.Environment;
@@ -55,12 +56,14 @@ public LdapAutoConfiguration(LdapProperties properties, Environment environment)
 	@ConditionalOnMissingBean
 	public LdapContextSource ldapContextSource() {
 		LdapContextSource source = new LdapContextSource();
-		source.setUserDn(this.properties.getUsername());
-		source.setPassword(this.properties.getPassword());
-		source.setAnonymousReadOnly(this.properties.getAnonymousReadOnly());
-		source.setBase(this.properties.getBase());
-		source.setUrls(this.properties.determineUrls(this.environment));
-		source.setBaseEnvironmentProperties(Collections.unmodifiableMap(this.properties.getBaseEnvironment()));
+		PropertyMapper propertyMapper = PropertyMapper.get().alwaysApplyingWhenNonNull();
+		propertyMapper.from(this.properties.getUsername()).to(source::setUserDn);
+		propertyMapper.from(this.properties.getPassword()).to(source::setPassword);
+		propertyMapper.from(this.properties.getAnonymousReadOnly()).to(source::setAnonymousReadOnly);
+		propertyMapper.from(this.properties.getBase()).to(source::setBase);
+		propertyMapper.from(this.properties.determineUrls(this.environment)).to(source::setUrls);
+		propertyMapper.from(this.properties.getBaseEnvironment()).to(
+				(baseEnvironment) -> source.setBaseEnvironmentProperties(Collections.unmodifiableMap(baseEnvironment)));
 		return source;
 	}
 

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

@@ -90,6 +90,17 @@ public void contextSourceWithExtraCustomization() {
 				});
 	}
 
+	@Test
+	public void contextSourceWithNoCustomization() {
+		this.contextRunner.run((context) -> {
+			LdapContextSource contextSource = context.getBean(LdapContextSource.class);
+			assertThat(contextSource.getUserDn()).isEqualTo("");
+			assertThat(contextSource.getPassword()).isEqualTo("");
+			assertThat(contextSource.isAnonymousReadOnly()).isFalse();
+			assertThat(contextSource.getBaseLdapPathAsString()).isEqualTo("");
+		});
+	}
+
 	@Test
 	public void templateExists() {
 		this.contextRunner.withPropertyValues("spring.ldap.urls:ldap://localhost:389")