Spring boot hibernate auto scan entities

Question

I'm fairly new to spring boot and trying to build a spring boot application with Java Persistence API + hibernate + mySQL persistence layer. But when I'm trying to fetch all records using, entityManager.createNamedQuery("SELECT * FROM Student s", Student.class).getResultList() it is giving me following exception.

java.lang.IllegalArgumentException: No query defined for that name [SELECT * FROM Student s] at org.hibernate.internal.AbstractSharedSessionContract.buildQueryFromName(AbstractSharedSessionContract.java:771) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final] at org.hibernate.internal.AbstractSharedSessionContract.createNamedQuery(AbstractSharedSessionContract.java:869) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final] at org.hibernate.internal.AbstractSessionImpl.createNamedQuery(AbstractSessionImpl.java:23) ~[hibernate-core-5.2.17.Final.jar:5.2.17.Final] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_131] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_131] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_131] at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_131] at org.springframework.orm.jpa.ExtendedEntityManagerCreator$ExtendedEntityManagerInvocationHandler.invoke(ExtendedEntityManagerCreator.java:350) ~[spring-orm-5.0.6.RELEASE.jar:5.0.6.RELEASE] at com.sun.proxy.$Proxy87.createNamedQuery(Unknown Source) ~[na:na] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_131] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_131] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_131] at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_131] at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:304) ~[spring-orm-5.0.6.RELEASE.jar:5.0.6.RELEASE] at com.sun.proxy.$Proxy87.createNamedQuery(Unknown Source) ~[na:na] at com.sys.sch.orm.dao.impl.StudentDaoImpl.findAll(StudentDaoImpl.java:30) ~[school-system-orm-1.0-SNAPSHOT.jar:na]

I'm trying to configure this project without persistence.xml or hibernate.cfg.xml and trying to use spring boot auto configurations. I've also added @EntityScan("com.sys.sch.orm.model") as most of the readings I've done.

@SpringBootApplication
@EnableAutoConfiguration
@EnableWebMvc
@ComponentScan({"com.sys.sch"})
@EntityScan("com.sys.sch.orm.model")
public class Program {

public static void main(String[] args) throws Exception {
    SpringApplication.run(Program.class, args);
}

Entity:

@Entity(name = "student")
public class Student {

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private long id;

@Column(name = "name")
private String name;

@Column(name = "birth_date")
private Date birthDate;

@CreationTimestamp
private Date dateCreated;

@UpdateTimestamp
private Date dateUpdated;
// getters and setters
}

dependencies:

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-jpa</artifactId>
    <version>2.0.2.RELEASE</version>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.15</version>
</dependency>
<dependency>
    <groupId>school-system</groupId>
    <artifactId>school-system-core</artifactId>
    <version>1.0-SNAPSHOT</version>
</dependency>

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
    <version>2.0.2.RELEASE</version>
</dependency>

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-thymeleaf</artifactId>
    <version>2.0.2.RELEASE</version>
</dependency>

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-devtools</artifactId>
    <optional>true</optional>
    <version>2.0.2.RELEASE</version>
</dependency>

application.properties:

server.port=8080
spring.datasource.url=jdbc:mysql://localhost:3306/schoolsys?createDatabaseIfNotExist=true
spring.datasource.username=root spring.datasource.password=
spring.datasource.tomcat.max-wait=20000
spring.datasource.tomcat.max-active=50
spring.datasource.tomcat.max-idle=20
spring.datasource.tomcat.min-idle=15
spring.jpa.database-platform=org.hibernate.dialect.MySQL5InnoDBDialect
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5InnoDBDialect
spring.jpa.properties.hibernate.id.new_generator_mappings=true
spring.jpa.properties.hibernate.format_sql=true
spring.jpa.hibernate.ddl-auto=update
logging.level.org.hibernate.SQL=DEBUG
logging.level.org.hibernate.type.descriptor.sql.BasicBinder=TRACE

Project structure

If anyone could show me what's I'm doing here wrong I will be very thankful.

codemonkey codemonkey · Accepted Answer · 2018-05-27T10:07:18

There is a difference between createNamedQuery() and createQuery().

createNamedQuery() takes the name of a predefined query:

@Entity(name = "student")
@NamedQuery(query = "select s from Student s", name = "findAllStudents")
public class Student {
    ...
}

This query can then be referenced by its name:

Query query = entitymanager.createNamedQuery("findAllStudents");
List<Student> students = query.getResultList();

On the other hand, createQuery() takes a jpql statement

Query query = entityManager.createQuery("select s from Student s");

Or more simply

Query query = entityManager.createQuery("from Student");

Spring boot hibernate auto scan entities

1 Answers