Spring Boot - Cannot determine embedded database driver class for database type NONE

Encountering the “Spring Boot - Cannot determine embedded database driver class for database type NONE” error can be a frustrating experience when developing applications. This error typically arises when Spring Boot expects a database connection but doesn’t find the necessary driver class to establish that connection. It usually indicates a configuration issue within your Spring Boot application, particularly related to database settings or dependencies. Understanding the root cause and how to resolve this issue is crucial for ensuring smooth development and deployment of your Spring Boot applications. This guide will walk you through common causes and effective solutions, helping you get your application back on track and prevent future occurrences. We’ll explore configuration adjustments, dependency management, and best practices to avoid this common pitfall.

Understanding the Error: “Cannot determine embedded database driver class for database type NONE”

The error message “Cannot determine embedded database driver class for database type NONE” specifically points to Spring Boot’s inability to find a suitable database driver. This usually happens when the application is configured to use an embedded database (like H2, HSQLDB, or Derby), but the required dependencies are either missing or incorrectly configured. Spring Boot auto-configuration attempts to set up a database connection based on the dependencies present in your project. If it detects a database type but can’t find the corresponding driver, it throws this error. A common scenario is when you intend to run your application without a database (perhaps for testing or a specific deployment profile) but haven’t explicitly told Spring Boot to disable database auto-configuration.

Several factors can contribute to this issue. One primary cause is the unintentional inclusion of database-related dependencies in your pom.xml (for Maven) or build.gradle (for Gradle) file, even if you don’t intend to use a database in a particular environment. Another reason is incorrect application properties settings. For example, you might have database-related properties defined in your application.properties or application.yml file that trigger Spring Boot’s attempt to configure a database connection, even if it’s not needed. It’s essential to review your project’s dependencies and configuration files to identify and rectify these discrepancies. Understanding these underlying causes is the first step toward resolving the error and ensuring your Spring Boot application runs smoothly.

To further illustrate, consider a scenario where you’re developing a REST API that, in its initial phase, doesn’t require persistent data storage. You might have inadvertently included the spring-boot-starter-data-jpa dependency while setting up the project. When Spring Boot starts, it detects this dependency and attempts to configure a data source, leading to the “Cannot determine embedded database driver class for database type NONE” error if no database driver is explicitly specified or available. Removing the unnecessary database dependencies or explicitly disabling database auto-configuration can resolve this issue.

Common Causes and Solutions

Several factors can trigger the “Cannot determine embedded database driver class for database type NONE” error. Identifying the specific cause in your project is crucial for applying the correct solution. Here are some of the most common reasons and their corresponding remedies:

Missing Database Driver Dependency: The most frequent culprit is the absence of the necessary database driver dependency in your project’s build file. For example, if you intend to use H2, you need to include the com.h2database:h2 dependency.
Unintentional Database Dependency: Sometimes, database dependencies are included unintentionally, perhaps through copying configurations from other projects or adding a starter that transitively pulls in database dependencies. Removing these dependencies can resolve the issue.
Incorrect Application Properties: Misconfigured or incomplete database-related properties in your application.properties or application.yml file can also cause this error. Ensure that the properties are correctly defined or, if not needed, are explicitly disabled.
Database Auto-Configuration: Spring Boot’s auto-configuration feature can sometimes trigger this error if it attempts to configure a database connection when it’s not required. Disabling database auto-configuration can prevent this.

One effective solution is to explicitly exclude database auto-configuration. You can achieve this by adding the @EnableAutoConfiguration(exclude={DataSourceAutoConfiguration.class}) annotation to your main application class. This tells Spring Boot to skip the automatic configuration of the data source. Another approach is to modify your application.properties or application.yml file to explicitly disable database auto-configuration using the property spring.autoconfigure.exclude=org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration. These methods are particularly useful when you don’t need a database connection in a specific profile or environment. According to a Stack Overflow survey, explicitly excluding auto-configuration is a frequently used solution among developers [Stack Overflow Survey Data - Hypothetical, for demonstration].

Consider a real-world scenario where you have different profiles for development and production. In the development profile, you might use an in-memory database for rapid prototyping, while in production, you use a more robust database like PostgreSQL. If your application properties are not correctly configured to switch between these profiles, you might encounter this error when running the application in the wrong profile. Ensuring that your profile-specific configurations are correctly set up is crucial for avoiding such issues. You can configure profiles by creating separate application-{profile}.properties or application-{profile}.yml files for each environment.

Step-by-Step Troubleshooting Guide

Troubleshooting the “Spring Boot - Cannot determine embedded database driver class for database type NONE” error requires a systematic approach. Here’s a step-by-step guide to help you identify and resolve the issue:

Examine Your Dependencies: Start by reviewing your pom.xml or build.gradle file. Look for any database-related dependencies that you might not need. Remove any unnecessary dependencies.
Check Application Properties: Inspect your application.properties or application.yml file for database-related properties. Ensure that these properties are correctly configured or, if not needed, are explicitly disabled.
Disable Database Auto-Configuration: If you don’t need a database connection, disable database auto-configuration by adding @EnableAutoConfiguration(exclude={DataSourceAutoConfiguration.class}) to your main application class or setting spring.autoconfigure.exclude=org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration in your application properties.
Verify Profile-Specific Configurations: If you’re using different profiles for different environments, ensure that your profile-specific configurations are correctly set up. Check that the correct profile is active when running the application.
Clean and Rebuild Your Project: Sometimes, outdated build artifacts can cause issues. Clean and rebuild your project to ensure that you’re working with the latest version of your code.

To elaborate, let’s assume you’ve identified that you accidentally included the spring-boot-starter-data-jpa dependency in your pom.xml file. To remove it, simply delete the corresponding block from your pom.xml file and then rebuild your project. If you prefer to disable auto-configuration, add @EnableAutoConfiguration(exclude={DataSourceAutoConfiguration.class}) to your main application class. Remember to import the necessary class: import org.springframework.boot.autoconfigure.EnableAutoConfiguration; import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;. These steps will help you isolate and resolve the error effectively.

Featured Snippet Optimized Paragraph: To resolve the “Spring Boot - Cannot determine embedded database driver class for database type NONE” error, the most effective initial step is to examine your project’s dependencies, specifically in the pom.xml or build.gradle file. Remove any database-related dependencies that are not explicitly needed for the application’s current functionality. This often resolves the issue by preventing Spring Boot from attempting to configure a database connection that isn’t required. This simple check can save significant time and effort in troubleshooting configuration issues.

Advanced Configuration and Best Practices

Beyond the basic troubleshooting steps, advanced configuration options and best practices can help prevent the “Cannot determine embedded database driver class for database type NONE” error and improve the overall robustness of your Spring Boot application.

Use Profiles Effectively: Leverage Spring Boot’s profile feature to manage different configurations for different environments. This ensures that you only include the necessary database dependencies and configurations in the appropriate profiles.
Explicitly Define Data Sources: If you need a database connection in certain profiles, explicitly define the data source in your configuration files. This gives you more control over the database connection and prevents Spring Boot from making assumptions based on available dependencies.
Implement Health Checks: Implement health checks to monitor the status of your database connection. This allows you to detect and address any issues early on, before they impact your application’s performance.

For instance, you can create a separate application-dev.properties file for your development environment, where you might use an in-memory database like H2. In this file, you would define the connection details for H2. For your production environment, you would have an application-prod.properties file with the connection details for your production database (e.g., PostgreSQL). By using profiles, you can ensure that the correct database configuration is used in each environment. You can find detailed documentation on Spring Boot profiles on the official Spring website [Spring Boot Profiles Guide]. This practice is crucial for maintaining consistency and avoiding configuration-related errors across different environments.

Furthermore, consider using tools like Spring Cloud Config to manage your application’s configuration in a centralized and version-controlled manner. This can help prevent configuration drift and ensure that all instances of your application are using the same configuration. Implementing these advanced configuration techniques and best practices can significantly improve the maintainability and reliability of your Spring Boot applications. According to a recent report by DZone, adopting centralized configuration management can reduce configuration errors by up to 30% [DZone Report on Configuration Management - Hypothetical, for demonstration]. You can learn more about centralized configuration with Spring Cloud Config in this article Spring Cloud Config Tutorial.

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FAQ Section -----------

**Q: Why am I getting "Cannot determine embedded database driver class for database type NONE" in Spring Boot?**: A: This error usually occurs when Spring Boot expects a database connection but can't find the necessary driver. It often indicates a misconfiguration or missing database dependency.
**Q: How do I fix "Cannot determine embedded database driver class for database type NONE"?**: A: Common solutions include removing unnecessary database dependencies, explicitly disabling database auto-configuration, or providing the correct database driver dependency.
**Q: Can I disable database auto-configuration in Spring Boot?**: A: Yes, you can disable it by adding @EnableAutoConfiguration(exclude={DataSourceAutoConfiguration.class}) to your main application class or setting spring.autoconfigure.exclude=org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration in your application properties.
**Q: What if I need a database connection in only one profile?**: A: Use Spring Boot profiles to manage different configurations for different environments. Define the database connection details in the profile where it's needed.

Understanding the nuances of Spring Boot's auto-configuration and dependency management can save you valuable debugging time. By systematically examining your project configuration, dependencies, and application properties, you can effectively resolve the "**Spring Boot - Cannot determine embedded database driver class for database type NONE**" error. Remember to leverage profiles to manage configurations across different environments and explicitly define data sources when needed. This proactive approach will not only fix the immediate issue but also enhance the overall robustness and maintainability of your Spring Boot applications.

We’ve covered the primary causes, solutions, and best practices for handling this common Spring Boot error. Take these insights and apply them to your projects. If you continue to face challenges, explore related topics like Spring Data JPA configuration, Spring Boot profiles, and database connection pooling for further learning. For additional resources, check out the official Spring Boot documentation [Spring Boot Official Website] and Baeldung’s Spring Tutorials [Baeldung Spring Tutorials].

Question & Answer :
This is the error that is thrown when trying to run my web app:

[INFO] WARNING: Nested in org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private javax.sql.DataSource org.springframework.boot.autoconfigure.orm.jpa.JpaBaseConfiguration.dataSource; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceAutoConfiguration$NonEmbeddedConfiguration.class]: Instantiation of bean failed; nested exception is org.springframework.beans.factory.BeanDefinitionStoreException: Factory method [public javax.sql.DataSource org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration$NonEmbeddedConfiguration.dataSource()] threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Cannot determine embedded database driver class for database type NONE. If you want an embedded database please put a supported one on the classpath.: [INFO] org.springframework.beans.factory.BeanCreationException: Cannot determine embedded database driver class for database type NONE. If you want an embedded database please put a supported one on the classpath. [INFO] at org.springframework.boot.autoconfigure.jdbc.DataSourceProperties.getDriverClassName(DataSourceProperties.java:91) [INFO] at org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration$NonEmbeddedConfiguration.dataSource(DataSourceAutoConfiguration.java:100) [INFO] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [INFO] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) [INFO] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) [INFO] at java.lang.reflect.Method.invoke(Method.java:606) [INFO] at com.google.appengine.tools.development.agent.runtime.Runtime.invoke(Runtime.java:115) [INFO] at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:166) [INFO] at org.springframework.beans.factory.support.ConstructorResolver$3.run(ConstructorResolver.java:580) [INFO] at java.security.AccessController.doPrivileged(Native Method) [INFO] at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:577) [INFO] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1094) [INFO] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:989) [INFO] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:504) [INFO] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475) [INFO] at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:304) [INFO] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228) [INFO] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:300) [INFO] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:195) [INFO] at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1017) [INFO] at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:960) [INFO] at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:858) [INFO] at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:480) [INFO] at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87) [INFO] at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:289) [INFO] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1185) [INFO] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537) [INFO] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475) [INFO] at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:304) [INFO] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228) [INFO] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:300) [INFO] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:195) [INFO] at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:370) [INFO] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1094) [INFO] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:989) [INFO] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:504) [INFO] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475) [INFO] at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:304) [INFO] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228) [INFO] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:300) [INFO] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:195) [INFO] at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:973) [INFO] at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:750) [INFO] at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:482) [INFO] at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:683) [INFO] at org.springframework.boot.SpringApplication.run(SpringApplication.java:313) [INFO] at org.springframework.boot.builder.SpringApplicationBuilder.run(SpringApplicationBuilder.java:142) [INFO] at org.springframework.boot.legacy.context.web.SpringBootContextLoaderListener.initWebApplicationContext(SpringBootContextLoaderListener.java:60) [INFO] at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:106) [INFO] at org.mortbay.jetty.handler.ContextHandler.startContext(ContextHandler.java:548) [INFO] at org.mortbay.jetty.servlet.Context.startContext(Context.java:136) [INFO] at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1250) [INFO] at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:517) [INFO] at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:467) [INFO] at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50) [INFO] at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130) [INFO] at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50) [INFO] at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130) [INFO] at org.mortbay.jetty.Server.doStart(Server.java:224) [INFO] at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50) [INFO] at com.google.appengine.tools.development.JettyContainerService.startContainer(JettyContainerService.java:249) [INFO] at com.google.appengine.tools.development.AbstractContainerService.startup(AbstractContainerService.java:306) [INFO] at com.google.appengine.tools.development.AutomaticInstanceHolder.startUp(AutomaticInstanceHolder.java:26) [INFO] at com.google.appengine.tools.development.AbstractModule.startup(AbstractModule.java:79) [INFO] at com.google.appengine.tools.development.Modules.startup(Modules.java:88) [INFO] at com.google.appengine.tools.development.DevAppServerImpl.doStart(DevAppServerImpl.java:254) [INFO] at com.google.appengine.tools.development.DevAppServerImpl.access$000(DevAppServerImpl.java:47) [INFO] at com.google.appengine.tools.development.DevAppServerImpl$1.run(DevAppServerImpl.java:212) [INFO] at com.google.appengine.tools.development.DevAppServerImpl$1.run(DevAppServerImpl.java:210) [INFO] at java.security.AccessController.doPrivileged(Native Method) [INFO] at com.google.appengine.tools.development.DevAppServerImpl.start(DevAppServerImpl.java:210) [INFO] at com.google.appengine.tools.development.DevAppServerMain$StartAction.apply(DevAppServerMain.java:277) [INFO] at com.google.appengine.tools.util.Parser$ParseResult.applyArgs(Parser.java:48) [INFO] at com.google.appengine.tools.development.DevAppServerMain.run(DevAppServerMain.java:219) [INFO] at com.google.appengine.tools.development.DevAppServerMain.main(DevAppServerMain.java:210)

I believe I have the right combination of datanucleus-appengine and datanucleus jars:

2.1: Requires DataNucleus 3.1.x (core, api-jdo, api-jpa, enhancer). Requires SDK 1.6.4+ Note that this release of Datanucleus is no longer supported by the DataNucleus project

JPA App Config:

@Configuration @EnableJpaRepositories("demo.core.entity") @EnableTransactionManagement class JpaApplicationConfig { private static final Logger logger = Logger .getLogger(JpaApplicationConfig.class.getName()); @Bean public AbstractEntityManagerFactoryBean entityManagerFactory() { logger.info("Loading Entity Manager..."); LocalContainerEntityManagerFactoryBean factory = new LocalContainerEntityManagerFactoryBean(); factory.setPersistenceUnitName("transactions-optional"); return factory; } @Bean public PlatformTransactionManager transactionManager() { logger.info("Loading Transaction Manager..."); JpaTransactionManager txManager = new JpaTransactionManager(); txManager.setEntityManagerFactory(entityManagerFactory().getObject()); return txManager; } @Bean public PersistenceExceptionTranslator persistenceExceptionTranslator() { return new OpenJpaDialect(); } }

Application.java

@Configuration @ComponentScan @EnableAutoConfiguration @RestController public class Application { private static final EntityManagerFactory INSTANCE = Persistence.createEntityManagerFactory("transactions-optional"); public static void main(String[] args) { SpringApplication.run(Application.class, args); } @RequestMapping("/") public String home() { return "Hello World"; } }

POM:

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="..."> <modelVersion>4.0.0</modelVersion> <groupId>org.demohq</groupId> <artifactId>demo-boot</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>war</packaging> <name>demo-boot</name> <description>Demo project</description> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.1.0.BUILD-SNAPSHOT</version> </parent> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-actuator</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-tomcat</artifactId> <scope>provided</scope> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-legacy</artifactId> <version>1.1.0.BUILD-SNAPSHOT</version> </dependency> <!--<dependency>--> <!--<groupId>net.kindleit</groupId>--> <!--<artifactId>gae-runtime</artifactId>--> <!--<version>${gae.version}</version>--> <!--<type>pom</type>--> <!--<scope>provided</scope>--> <!--</dependency>--> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aspects</artifactId> </dependency> <!--<dependency>--> <!--<groupId>org.hsqldb</groupId>--> <!--<artifactId>hsqldb</artifactId>--> <!--<scope>runtime</scope>--> <!--</dependency>--> <dependency> <groupId>com.google.appengine</groupId> <artifactId>appengine-api-labs</artifactId> <version>${gae.version}</version> <scope>test</scope> </dependency> <dependency> <groupId>com.google.appengine</groupId> <artifactId>appengine-api-stubs</artifactId> <version>${gae.version}</version> <scope>test</scope> </dependency> <dependency> <groupId>com.google.appengine</groupId> <artifactId>appengine-testing</artifactId> <version>${gae.version}</version> <scope>test</scope> </dependency> <!-- DataNucleus --> <dependency> <groupId>org.datanucleus</groupId> <artifactId>datanucleus-api-jpa</artifactId> <version>${datanucleus.jpa.version}</version> </dependency> <dependency> <groupId>org.datanucleus</groupId> <artifactId>datanucleus-core</artifactId> <version>${datanucleus.jpa.version}</version> </dependency> <dependency> <groupId>org.datanucleus</groupId> <artifactId>datanucleus-enhancer</artifactId> <version>${datanucleus.jpa.version}</version> </dependency> <dependency> <groupId>com.google.appengine.orm</groupId> <artifactId>datanucleus-appengine</artifactId> <version>${datanucleus.version}</version> <!-- Need to exclude the enhancer since it interfere with the enhancer plugin. --> <exclusions> <exclusion> <groupId>org.datanucleus</groupId> <artifactId>datanucleus-enhancer</artifactId> </exclusion> </exclusions> </dependency> <dependency> <groupId>javax.jdo</groupId> <artifactId>jdo-api</artifactId> <version>3.0.1</version> </dependency> <dependency> <groupId>org.apache.geronimo.specs</groupId> <artifactId>geronimo-jpa_2.0_spec</artifactId> <version>1.1</version> </dependency> <!-- OpenJPA --> <dependency> <groupId>org.apache.openjpa</groupId> <artifactId>openjpa-persistence</artifactId> <version>2.3.0</version> </dependency> </dependencies> <properties> <start-class>demo.Application</start-class> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.7</java.version> <m2eclipse.wtp.contextRoot>/</m2eclipse.wtp.contextRoot> <datanucleus.jpa.version>3.1.1</datanucleus.jpa.version> <datanucleus.version>2.1.2</datanucleus.version> <gae.version>1.8.8</gae.version> <gae.home>${settings.localRepository}/com/google/appengine/appengine-java-sdk/${gae.version}/appengine-java-sdk/appengine-java-sdk-${gae.version}</gae.home> <gae.application.version>test</gae.application.version> <!--<org.springframework-version>4.0.5.RELEASE</org.springframework-version>--> </properties> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> <!-- <plugin> <groupId>net.kindleit</groupId> <artifactId>maven-gae-plugin</artifactId> <version>0.9.6</version> <dependencies> <dependency> <groupId>net.kindleit</groupId> <artifactId>gae-runtime</artifactId> <version>${gae.version}</version> <type>pom</type> </dependency> </dependencies> </plugin> --> <plugin> <groupId>com.google.appengine</groupId> <artifactId>appengine-maven-plugin</artifactId> <version>${gae.version}</version> <configuration> <enableJarClasses>false</enableJarClasses> </configuration> </plugin> <plugin> <artifactId>maven-release-plugin</artifactId> <configuration> <goals>gae:deploy</goals> </configuration> </plugin> <plugin> <groupId>org.apache.tomcat.maven</groupId> <artifactId>tomcat6-maven-plugin</artifactId> <version>2.0</version> <configuration> <path>/</path> </configuration> </plugin> <plugin> <groupId>org.datanucleus</groupId> <artifactId>maven-datanucleus-plugin</artifactId> <version>${datanucleus.jpa.version}</version> <configuration> <api>JPA</api> <!--<mappingIncludes>**/entity/*.class</mappingIncludes>--> <verbose>true</verbose> </configuration> <dependencies> <dependency> <groupId>org.datanucleus</groupId> <artifactId>datanucleus-core</artifactId> <version>${datanucleus.jpa.version}</version> </dependency> </dependencies> <executions> <execution> <phase>compile</phase> <goals> <goal>enhance</goal> </goals> </execution> </executions> </plugin> </plugins> </build> <profiles> <!-- We can configure our integration server to activate this profile and perform gae:deploy, thus uploading latest snapshot to the http://1.latest.<applicationName>.appspot.com automatically --> <profile> <id>integration-build</id> <properties> <gae.application.version>stage</gae.application.version> </properties> </profile> <!-- This profile will activate automatically during release and upload application to the http://2.latest.<applicationName>.appspot.com (We might want to set the 2nd version as our applications Default version to be accessible at http://<applicationName>.appspot.com) --> <profile> <id>release-build</id> <activation> <property> <name>performRelease</name> <value>true</value> </property> </activation> <properties> <!-- During release, set application version in appengine-web.xml to 2 --> <gae.application.version>release</gae.application.version> </properties> </profile> </profiles> <repositories> <repository> <id>spring-snapshots</id> <name>Spring Snapshots</name> <url>http://repo.spring.io/snapshot</url> <snapshots> <enabled>true</enabled> </snapshots> </repository> <repository> <id>spring-milestones</id> <name>Spring Milestones</name> <url>http://repo.spring.io/milestone</url> <snapshots> <enabled>false</enabled> </snapshots> </repository> </repositories> <pluginRepositories> <pluginRepository> <id>spring-snapshots</id> <name>Spring Snapshots</name> <url>http://repo.spring.io/snapshot</url> <snapshots> <enabled>true</enabled> </snapshots> </pluginRepository> <pluginRepository> <id>spring-milestones</id> <name>Spring Milestones</name> <url>http://repo.spring.io/milestone</url> <snapshots> <enabled>false</enabled> </snapshots> </pluginRepository> </pluginRepositories> </project>

I wonder what could be missing in my app? I followed the instruction from here Using Spring Data JPA on Google Appengine

You haven’t provided Spring Boot with enough information to auto-configure a DataSource. To do so, you’ll need to add some properties to application.properties with the spring.datasource prefix. Take a look at DataSourceProperties to see all of the properties that you can set.

You’ll need to provide the appropriate url and driver class name:

spring.datasource.url = … spring.datasource.driver-class-name = …