Spring Data Repository StackOverflow

Question

Found some strange behavoir when working with Spring Data Repositories.

I wrote these classes and interfaces:

@Transactional(readOnly = true)
public interface UserRepository extends Repository<User, Integer> {

    @Transactional
    @Modifying
    @Query("DELETE FROM User u WHERE u.id=:id")
    int delete(@Param("id") int id);

    @Transactional
    User save(User user);

    User findOne(Integer id);

    List<User> findAll();
}


public interface AbstractRepository<T> {

    T save(T user);

    // false if not found
    boolean delete(int id);

    // null if not found
    T get(int id);

    List<T> getAll();
    }



@Repository
public class UserRepositoryImpl implements AbstractRepository<User> {

    @Autowired
    private JpaUserRepository repository;

    @Override
    public User save(User user) {
        return repository.save(user);
    }

    @Override
    public boolean delete(int id) {
        return repository.delete(id) != 0;
    }

    @Override
    public User get(int id) {
        return repository.findOne(id);
    }

    @Override
    public List<User> getAll() {
        return repository.findAll();
    }
}

When I try to test UserRepositoryImpl, java.lang.StackOverflowError is thrown

Caused by: java.lang.StackOverflowError
    at org.springframework.data.repository.util.ClassUtils.unwrapReflectionException(ClassUtils.java:166)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.executeMethodOn(RepositoryFactorySupport.java:505)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:478)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:460)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:61)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:282)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:136)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:115)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213)
    at com.sun.proxy.$Proxy55.save(Unknown Source)
    at ru.emitrohin.votingsystem.repository.UserRepositoryImpl.save(RestaurantRepositoryImpl.java:24)
    at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
    at  sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)

I see that there is some problem with save() method. Also stackoverflow is thrown on delete() method.

I've already found the solution. My problem disappears when I change name of interface that extends Repository interface to (for example) JpaUserRepository.

So, the question is "What is going on". Why stackoverflow is thrown when interface name that implements spring data repository matches pattern Classname Repository?

my pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns="http://maven.apache.org/POM/4.0.0"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>xxx</groupId>
    <artifactId>xxx</artifactId>
    <packaging>war</packaging>

    <version>1.0-SNAPSHOT</version>

    <name>xxx</name>
    <url>xxx</url>

    <properties>
        <java.version>1.8</java.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>

        <tomcat.version>8.0.33</tomcat.version>
        <spring.version>4.3.4.RELEASE</spring.version>
        <spring-security.version>4.2.0.RELEASE</spring-security.version>
        <spring-data-jpa.version>1.10.4.RELEASE</spring-data-jpa.version>

        <!-- Logging -->
        <logback.version>1.1.7</logback.version>
        <slf4j.version>1.7.21</slf4j.version>

        <!--DB-->
        <postgresql.version>9.4.1211</postgresql.version>

        <!--Tests-->
        <junit.version>4.12</junit.version>

        <!-- Hibernate -->
        <hibernate.version>5.2.4.Final</hibernate.version>
        <hibernate-validator.version>5.3.2.Final</hibernate-validator.version>

        <!--Tools-->
        <ehcache.version>2.10.3</ehcache.version>

    </properties>

    <build>
        <finalName>xxx</finalName>
        <defaultGoal>package</defaultGoal>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.1</version>
                <configuration>
                    <source>${java.version}</source>
                    <target>${java.version}</target>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>2.19.1</version>
                <configuration>
                    <argLine>-Dfile.encoding=UTF-8</argLine>
                </configuration>
            </plugin>

            <!--  http://stackoverflow.com/questions/4305935/is-it-possible-to-supply-tomcat6s-context-xml-file-via-the-maven-cargo-plugin#4417945 -->
            <plugin>
                <groupId>org.codehaus.cargo</groupId>
                <artifactId>cargo-maven2-plugin</artifactId>
                <version>1.5.0</version>
                <configuration>
                    <container>
                        <containerId>tomcat8x</containerId>
                        <systemProperties>
                            <file.encoding>UTF-8</file.encoding>
                            <spring.profiles.active>tomcat,datajpa</spring.profiles.active>
                        </systemProperties>
                        <dependencies>
                            <dependency>
                                <groupId>org.postgresql</groupId>
                                <artifactId>postgresql</artifactId>
                            </dependency>
                        </dependencies>
                    </container>
                    <configuration>
                        <configfiles>
                            <configfile>
                                <file>src/main/resources/tomcat/context.xml</file>
                                <todir>conf/Catalina/localhost/</todir>
                                <tofile>context.xml.default</tofile>
                            </configfile>
                        </configfiles>
                    </configuration>
                    <deployables>
                        <deployable>
                            <groupId>com.xxx</groupId>
                            <artifactId>xxx</artifactId>
                            <type>war</type>
                            <properties>
                                <context>${project.build.finalName}</context>
                            </properties>
                        </deployable>
                    </deployables>
                </configuration>
            </plugin>
        </plugins>
    </build>

    <dependencies>

        <!-- Logging with SLF4J & LogBack -->

        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <version>${logback.version}</version>
            <scope>runtime</scope>
        </dependency>

        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>jcl-over-slf4j</artifactId>
            <version>${slf4j.version}</version>
            <scope>runtime</scope>
        </dependency>

        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <version>${logback.version}</version>
            <scope>runtime</scope>
        </dependency>

        <!-- Spring -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>${spring.version}</version>
            <exclusions>
                <exclusion>
                    <groupId>commons-logging</groupId>
                    <artifactId>commons-logging</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-jpa</artifactId>
            <version>${spring-data-jpa.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${spring.version}</version>
            <exclusions>
                <exclusion>
                    <groupId>commons-logging</groupId>
                    <artifactId>commons-logging</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

        <!-- spring security-->

        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-web</artifactId>
            <version>${spring-security.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-config</artifactId>
            <version>${spring-security.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-test</artifactId>
            <version>${spring-security.version}</version>
        </dependency>

        <!--hibernate-->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>${hibernate.version}</version>
        </dependency>

        <dependency>
            <groupId>javax.transaction</groupId>
            <artifactId>jta</artifactId>
            <version>1.1</version>
            <scope>runtime</scope>
        </dependency>

        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-validator</artifactId>
            <version>${hibernate-validator.version}</version>
        </dependency>

        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-ehcache</artifactId>
            <version>${hibernate.version}</version>
        </dependency>

        <dependency>
            <groupId>net.sf.ehcache</groupId>
            <artifactId>ehcache</artifactId>
            <version>${ehcache.version}</version>
        </dependency>

        <!--Web-->
        <dependency>
            <groupId>org.apache.tomcat</groupId>
            <artifactId>tomcat-servlet-api</artifactId>
            <version>${tomcat.version}</version>
            <scope>provided</scope>
        </dependency>

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>

        <!--Test-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>${junit.version}</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${spring.version}</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.mockito</groupId>
            <artifactId>mockito-core</artifactId>
            <version>2.2.21</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>2.8.1</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.8.1</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.datatype</groupId>
            <artifactId>jackson-datatype-jsr310</artifactId>
            <version>2.8.4</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.datatype</groupId>
            <artifactId>jackson-datatype-hibernate5</artifactId>
            <version>2.8.4</version>
        </dependency>
        <dependency>
            <groupId>org.hamcrest</groupId>
            <artifactId>hamcrest-library</artifactId>
            <version>1.3</version>
            <scope>test</scope>
        </dependency>
    </dependencies>


    <profiles>
        <profile>
            <id>hsqldb</id>
            <dependencies>
                <dependency>
                    <groupId>org.hsqldb</groupId>
                    <artifactId>hsqldb</artifactId>
                    <version>2.3.4</version>
                </dependency>
            </dependencies>
        </profile>
    </profiles>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-framework-bom</artifactId>
                <version>${spring.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
</dependencyManagement>

Answer 1

Well, the problem comes not because of the Classname RepositoryImpl naming but because of the RepositoryClassname Impl naming . What you are doing with this is telling Spring that you are provinding custom behaviour to some methods on the RepositoryClassname interface . That said, Spring is implementing all the standard CRUD methods in JpaRepository for you. Your implementation lets you inject the repository bean but it's meant to be used as part of the implementation and not just for delegating . When you implement save() in your Impl class, you are in fact giving a custom implementation for the interface save() method so, while you call the interface save() in your "custom" implementation, you are forcing an infinite loop that ends up with the stackoverflow exception.

If you are not going to give a custom behaviour just don't declare the method in your Impl class. On the other hand, if you are not trying to give custom behaviour to some interface methods, and you were just trying to create a separate repository, don't name it RepositoryInterfaceName Impl. If you were trying to modify the implementation, just don't call the interface.save() method.

PS: usually it's a bad practice to use @Transactional at persistence layer, I think it's always better to use @Transactional on the service layer, as it's going to handle your business logic. Check this post for more information.