Add auto-configuration for JdbcClient

Closes gh-36579

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/jdbc/JdbcClientAutoConfiguration.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2012-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.autoconfigure.jdbc;
+
+import org.springframework.boot.autoconfigure.AutoConfiguration;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnSingleCandidate;
+import org.springframework.boot.sql.init.dependency.DatabaseInitializationDependencyConfigurer;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Import;
+import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate;
+import org.springframework.jdbc.core.simple.JdbcClient;
+
+/**
+ * {@link EnableAutoConfiguration Auto-configuration} for {@link JdbcClient}.
+ *
+ * @author Stephane Nicoll
+ * @since 3.2.0
+ */
+@AutoConfiguration(after = JdbcTemplateAutoConfiguration.class)
+@ConditionalOnSingleCandidate(NamedParameterJdbcTemplate.class)
+@ConditionalOnMissingBean(JdbcClient.class)
+@Import(DatabaseInitializationDependencyConfigurer.class)
+public class JdbcClientAutoConfiguration {
+
+	@Bean
+	JdbcClient jdbcClient(NamedParameterJdbcTemplate jdbcTemplate) {
+		return JdbcClient.create(jdbcTemplate);
+	}
+
+}

spring-boot-project/spring-boot-autoconfigure/src/main/resources/META-INF/spring/org.springframework.boot.autoconfigure.AutoConfiguration.imports

@@ -68,6 +68,7 @@ org.springframework.boot.autoconfigure.info.ProjectInfoAutoConfiguration
 org.springframework.boot.autoconfigure.integration.IntegrationAutoConfiguration
 org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration
 org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration
+org.springframework.boot.autoconfigure.jdbc.JdbcClientAutoConfiguration
 org.springframework.boot.autoconfigure.jdbc.JdbcTemplateAutoConfiguration
 org.springframework.boot.autoconfigure.jdbc.JndiDataSourceAutoConfiguration
 org.springframework.boot.autoconfigure.jdbc.XADataSourceAutoConfiguration

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/jdbc/JdbcClientAutoConfigurationTests.java

@@ -0,0 +1,100 @@
+/*
+ * Copyright 2012-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.autoconfigure.jdbc;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.autoconfigure.flyway.FlywayAutoConfiguration;
+import org.springframework.boot.autoconfigure.liquibase.LiquibaseAutoConfiguration;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.jdbc.core.JdbcOperations;
+import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate;
+import org.springframework.jdbc.core.simple.JdbcClient;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+
+/**
+ * Tests for {@link JdbcClientAutoConfiguration}.
+ *
+ * @author Stephane Nicoll
+ */
+class JdbcClientAutoConfigurationTests {
+
+	private final ApplicationContextRunner contextRunner = new ApplicationContextRunner()
+		.withPropertyValues("spring.datasource.generate-unique-name=true")
+		.withConfiguration(AutoConfigurations.of(DataSourceAutoConfiguration.class, JdbcTemplateAutoConfiguration.class,
+				JdbcClientAutoConfiguration.class));
+
+	@Test
+	void jdbcClientWhenNoAvailableJdbcTemplateIsNotCreated() {
+		new ApplicationContextRunner().withConfiguration(AutoConfigurations.of(DataSourceAutoConfiguration.class))
+			.run((context) -> assertThat(context).doesNotHaveBean(JdbcClient.class));
+	}
+
+	@Test
+	void jdbcClientWhenExistingJdbcTemplateIsCreated() {
+		this.contextRunner.run((context) -> {
+			assertThat(context).hasSingleBean(JdbcClient.class);
+			NamedParameterJdbcTemplate namedParameterJdbcTemplate = context.getBean(NamedParameterJdbcTemplate.class);
+			assertThat(namedParameterJdbcTemplate.getJdbcOperations()).isEqualTo(context.getBean(JdbcOperations.class));
+		});
+	}
+
+	@Test
+	void jdbcClientWithCustomJdbcClientIsNotCreated() {
+		this.contextRunner.withBean("customJdbcClient", JdbcClient.class, () -> mock(JdbcClient.class))
+			.run((context) -> {
+				assertThat(context).hasSingleBean(JdbcClient.class);
+				assertThat(context.getBean(JdbcClient.class)).isEqualTo(context.getBean("customJdbcClient"));
+			});
+	}
+
+	@Test
+	void jdbcClientIsOrderedAfterFlywayMigration() {
+		this.contextRunner.withUserConfiguration(JdbcClientDataSourceMigrationValidator.class)
+			.withPropertyValues("spring.flyway.locations:classpath:db/city")
+			.withConfiguration(AutoConfigurations.of(FlywayAutoConfiguration.class))
+			.run((context) -> {
+				assertThat(context).hasNotFailed().hasSingleBean(JdbcClient.class);
+				assertThat(context.getBean(JdbcClientDataSourceMigrationValidator.class).count).isZero();
+			});
+	}
+
+	@Test
+	void jdbcClientIsOrderedAfterLiquibaseMigration() {
+		this.contextRunner.withUserConfiguration(JdbcClientDataSourceMigrationValidator.class)
+			.withPropertyValues("spring.liquibase.changeLog:classpath:db/changelog/db.changelog-city.yaml")
+			.withConfiguration(AutoConfigurations.of(LiquibaseAutoConfiguration.class))
+			.run((context) -> {
+				assertThat(context).hasNotFailed().hasSingleBean(JdbcClient.class);
+				assertThat(context.getBean(JdbcClientDataSourceMigrationValidator.class).count).isZero();
+			});
+	}
+
+	static class JdbcClientDataSourceMigrationValidator {
+
+		private final Integer count;
+
+		JdbcClientDataSourceMigrationValidator(JdbcClient jdbcClient) {
+			this.count = jdbcClient.sql("SELECT COUNT(*) from CITY").query().singleValue(Integer.class);
+		}
+
+	}
+
+}

spring-boot-project/spring-boot-docs/src/docs/asciidoc/data/sql.adoc

@@ -1,6 +1,6 @@
 [[data.sql]]
 == SQL Databases
-The {spring-framework}[Spring Framework] provides extensive support for working with SQL databases, from direct JDBC access using `JdbcTemplate` to complete "`object relational mapping`" technologies such as Hibernate.
+The {spring-framework}[Spring Framework] provides extensive support for working with SQL databases, from direct JDBC access using `JdbcClient` or `JdbcTemplate` to complete "`object relational mapping`" technologies such as Hibernate.
 {spring-data}[Spring Data] provides an additional level of functionality: creating `Repository` implementations directly from interfaces and using conventions to generate queries from your method names.
 
 
@@ -176,6 +176,17 @@ If more than one `JdbcTemplate` is defined and no primary candidate exists, the
 
 
 
+[[data.sql.jdbc-client]]
+=== Using JdbcClient
+Spring's `JdbcClient` is auto-configured based on the presence of a `NamedParameterJdbcTemplate`.
+You can inject it directly in your own beans as well, as shown in the following example:
+
+include::code:MyBean[]
+
+If you rely on auto-configuration to create the underlying `JdbcTemplate`, any customization using `spring.jdbc.template.*` properties are taken into account in the client as well.
+
+
+
 [[data.sql.jpa-and-spring-data]]
 === JPA and Spring Data JPA
 The Java Persistence API is a standard technology that lets you "`map`" objects to relational databases.

spring-boot-project/spring-boot-docs/src/docs/asciidoc/howto/data-initialization.adoc

@@ -217,6 +217,7 @@ Spring Boot will automatically detect beans of the following types that depends
 - `AbstractEntityManagerFactoryBean` (unless configprop:spring.jpa.defer-datasource-initialization[] is set to `true`)
 - `DSLContext` (jOOQ)
 - `EntityManagerFactory` (unless configprop:spring.jpa.defer-datasource-initialization[] is set to `true`)
+- `JdbcClient`
 - `JdbcOperations`
 - `NamedParameterJdbcOperations`
 

spring-boot-project/spring-boot-docs/src/main/java/org/springframework/boot/docs/data/sql/jdbcclient/MyBean.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2012-2023 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.docs.data.sql.jdbcclient;
+
+import org.springframework.jdbc.core.simple.JdbcClient;
+import org.springframework.stereotype.Component;
+
+@Component
+public class MyBean {
+
+	private final JdbcClient jdbcClient;
+
+	public MyBean(JdbcClient jdbcClient) {
+		this.jdbcClient = jdbcClient;
+	}
+
+	public void doSomething() {
+		/* @chomp:line this.jdbcClient ... */ this.jdbcClient.sql("delete from customer").update();
+	}
+
+}

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/jdbc/SpringJdbcDependsOnDatabaseInitializationDetector.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,14 +16,13 @@
 
 package org.springframework.boot.jdbc;
 
-import java.util.Arrays;
-import java.util.HashSet;
 import java.util.Set;
 
 import org.springframework.boot.sql.init.dependency.AbstractBeansOfTypeDependsOnDatabaseInitializationDetector;
 import org.springframework.boot.sql.init.dependency.DependsOnDatabaseInitializationDetector;
 import org.springframework.jdbc.core.JdbcOperations;
 import org.springframework.jdbc.core.namedparam.NamedParameterJdbcOperations;
+import org.springframework.jdbc.core.simple.JdbcClient;
 
 /**
  * {@link DependsOnDatabaseInitializationDetector} for Spring Framework's JDBC support.
@@ -35,7 +34,7 @@ class SpringJdbcDependsOnDatabaseInitializationDetector
 
 	@Override
 	protected Set<Class<?>> getDependsOnDatabaseInitializationBeanTypes() {
-		return new HashSet<>(Arrays.asList(JdbcOperations.class, NamedParameterJdbcOperations.class));
+		return Set.of(JdbcClient.class, JdbcOperations.class, NamedParameterJdbcOperations.class);
 	}
 
 }