Exporting Spring Data JPA Repositories as REST Services using Spring Data REST

Spring Data modules provides various modules to work with various types of datasources like RDBMS, NOSQL stores etc in unified way. In my previous article  SpringMVC4 + Spring Data JPA + SpringSecurity configuration using JavaConfig I have explained how to configure Spring Data JPA using JavaConfig.

Now in this post let us see how we can use Spring Data JPA repositories and export JPA entities as REST endpoints using Spring Data REST.

First let us configure spring-data-jpa and spring-data-rest-webmvc dependencies in our pom.xml.


Make sure you have latest released versions configured correctly, otherwise you will encounter the following error:
java.lang.ClassNotFoundException: org.springframework.data.mapping.SimplePropertyHandler

Create JPA entities.


Configure DispatcherServlet using AbstractAnnotationConfigDispatcherServletInitializer.

Observe that we have added RepositoryRestMvcConfiguration.class to getServletConfigClasses() method.
RepositoryRestMvcConfiguration is the one which does the heavy lifting of looking for Spring Data Repositories and exporting them as REST endpoints.



Create Spring Data JPA repositories for JPA entities.


That's it. Spring Data REST will take care of rest of the things.

You can use spring Rest Shell https://github.com/spring-projects/rest-shell or Chrome's Postman Addon to test the exported REST services.

D:\rest-shell-1.2.1.RELEASE\bin>rest-shell
http://localhost:8080:>

Now we can change the baseUri using baseUri command as follows:
http://localhost:8080:>baseUri http://localhost:8080/spring-data-rest-demo/rest/
http://localhost:8080/spring-data-rest-demo/rest/>


http://localhost:8080/spring-data-rest-demo/rest/>list
rel         href
======================================================================================
users       http://localhost:8080/spring-data-rest-demo/rest/users{?page,size,sort}
roles       http://localhost:8080/spring-data-rest-demo/rest/roles{?page,size,sort}
contacts    http://localhost:8080/spring-data-rest-demo/rest/contacts{?page,size,sort}

Note: It seems there is an issue with rest-shell when the DispatcherServlet url mapped to "/" and issue list command it responds with "No resources found".

http://localhost:8080/spring-data-rest-demo/rest/>get users/

You can find the source code at https://github.com/sivaprasadreddy/sivalabs-blog-samples-code/tree/master/spring-data-rest-demo
For more Info on Spring Rest Shell: https://github.com/spring-projects/rest-shell

SpringMVC4 + Spring Data JPA + SpringSecurity configuration using JavaConfig

In this article we will see how to configure and integrate SpringMVC4, Spring Data JPA with Hibernate and SpringSecurity using JavaConfig.

1. First let's configure all the necessary dependencies in pom.xml


2. Configure database connection properties and email settings in application.properties


3. Configure common Service Layer beans such as PropertySourcesPlaceholderConfigurer and JavaMailSender etc in com.sivalabs.springapp.config.AppConfig.java


Observe that we have excluded the package "com.sivalabs.springapp.web.*" from component scanning using new REGEX excludeFilter type.
If we don't exclude web related packages and tries to run JUnit test for service layer beans we will encounter the following Exception:

java.lang.IllegalArgumentException: A ServletContext is required to configure default servlet handling

Also note that we have enabled Caching using @EnableCaching, so we should declare CacheManager bean.

4. Configure Persistence Layer beans in com.sivalabs.springapp.config.PersistenceConfig.java as follows:



Here we have configured DataSource and JPA EntityManagerFactory bean using Hibernate implementation.
Also we have configured DataSourceInitializer bean to initialize and populate our tables with seed data. We can enable/disable executing this db.sql script by changing init-db property value in application.properties.
And finally we have enabled Spring Data JPA repositories scanning using @EnableJpaRepositories to scan "com.sivalabs.springapp.repositories" package for JPA repository interfaces.

5. Now let us configure Web related beans in com.sivalabs.springapp.web.config.WebMvcConfig.java


6. Configure DispatcherService using AbstractAnnotationConfigDispatcherServletInitializer convinient class.


Here few things to note are we configured AppConfig.class as RootConfig classes and WebMvcConfig.class as ServletConfigClasses which is similar to how we configure in web.xml using ContextLoaderListener and DispatcherServlet's contextConfigLocation .
Also we have registered OpenEntityManagerInViewFilter to enable lazy loading of JPA entity graphs in view rendering phase.

7. Let us configure SpringSecurity.

First let us create a SecurityUser class which extends our application specific User class and implements org.springframework.security.core.userdetails.UserDetails.


We will implement a custom UserDetailsService and use Spring Data JPA repositories to load User details.


Now create com.sivalabs.springapp.config.SecurityConfig.java which contains SpeingSecurity related bean definitions.


Update SpringWebAppInitializer which we created eariler to add SecurityConfig configuration class.


As per our SpringSecurity custom Form Login configuration, we will use the following login form in login.jsp.


Once we successfully login we can obtain the authenticated use details using and secure parts of the view using as follows:


You can find the source code at github https://github.com/sivaprasadreddy/sivalabs-blog-samples-code/tree/master/springmvc-datajpa-security-demo

There are few issues while running the same application on JBoss AS 7.1. I have made few changes to run on JBossAS7.1 and published code at https://github.com/sivaprasadreddy/sivalabs-blog-samples-code/tree/master/springmvc-datajpa-security-demo-jboss7