How should I create H2 using SpringBoot? - spring

Question

I'm starting to play with Spring Boot and as part of that I want to create an in memory DB to work with and bootstrap with the application.
Given the config/code below I get no errors in the startup log and can access the application ok, so it does startup (I get template errors about objects not existing), but I don't get any data back from the DAO when calling findAll() (or if I try to call findById(int) ).
So while it seems things are ok (no error in log, log shows it finds the sql to create schema ad attempts to run the data.sql statements) when I try to access data via the DAO I get no Exception, but no data returned.
Any ideas or observations on the code that might be a problem?
I've added the Spring Data / H2 stuff to my pom:
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>com.h2database</groupId>
<artifactId>h2</artifactId>
</dependency>
Spring DAO:
public interface PersonDao extends CrudRepository<Person, Integer> {
}
DB props in application.properties:
server.contextPath=/
server.port=8080
spring.mvc.view.suffix=.ftl
datasource.mine.jdbcUrl=jdbc:h2:tcp://localhost/mem:clubmanagement
datasource.mine.user=sa
datasource.mine.password=
datasource.mine.poolSize=30
logging.level.org.springframework.web=DEBUG
logging.level.org.hibernate=DEBUG
spring.jpa.hibernate.ddl-auto=create
My service:
#Service
public class MemberServiceImpl implements MemberService {
#Autowired
PersonDao dao;
#Override
public Optional<ClubMember> getClubMember(int id) {
Person dbPerson = dao.findOne(id);
if(dbPerson == null) {
return Optional.empty();
}
return Optional.of(fromEntity(dbPerson));
}
#Override
public List<ClubMember> allMembers() {
Iterable<Person> people = dao.findAll();
List<ClubMember> members = new ArrayList<>();
people.forEach(person -> {
members.add(fromEntity(person));
});
return members;
}
private ClubMember fromEntity(Person p) {
ClubMember member = new ClubMember();
member.setCurrentGrade(p.getCurrentGrade());
member.setFirstName(p.getFirstName());
member.setLastName(p.getLastName());
member.setAssociationMemberId(p.getAssociationMemberId());
member.setLastGradingDate(p.getLastGradingDate());
return member;
}
}
Schema.sql in resources/ :
create table CLUB
(id int not null, name varchar(60), association_member_id int);
create table PERSON
(
id int not null, grade_id int, first_name varchar(35), last_name varchar(35),
association_membership varchar(12), last_grading_date date
);
create table GRADE
(id int not null, name varchar(20));
In data.sql (again in resources directory):
insert into club (id, name, association_member_id) values (1, 'some club', '123');
insert into person (id, grade_id, first_name, last_name, association_membership, last_grading_date)
values (1, 1, 'name', 'lastname', 'a1234', '2016-03-23');
Entity class I am trying to retrieve (Trying to use Lombock, also new to me, to generate getters/setters):
#Entity
#Table(name = "person")
public #Data class Person {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "id")
private int id;
#JoinColumn(name = "grade_id")
private GRADE currentGrade;
#Column(name = "first_name")
private String firstName;
#Column(name = "last_name")
private String lastName;
#Column(name = "association_membership")
private String associationMemberId;
#Column(name = "last_grading_date")
#Temporal(value = TemporalType.DATE)
private Date lastGradingDate;
}

Answer 1

you want to add H2 database, but you added HSQLDB, please replace
<dependency>
<groupId>org.hsqldb</groupId>
<artifactId>hsqldb</artifactId>
<scope>runtime</scope>
</dependency>
with
<dependency>
<groupId>com.h2database</groupId>
<artifactId>h2</artifactId>
</dependency>
EDIT
I noticed you have multiple issues in your code:
default schema file name is schema.sql not Schema.sql
names of tables in schema.sql are different than names in data.sql (PERSON vs person)
you used this spring.jpa.hibernate.ddl-auto=create in application.properties (default option), in this case JPA databases schema only will be automatically created (without data creation), so data.sql will not be executed, to fix this issues you can use validate or update option
I will write one simple example how to use H2 database with spring boot and JPA
This is the project structure:
Grade Entity
package com.shijazi;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;
#Entity
#Table(name="GRADE")
public class Grade {
#Id
#GeneratedValue
private int id;
private String name;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Grade(int id, String name) {
super();
this.id = id;
this.name = name;
}
public Grade() {
}
}
GradeRepository.java
package com.shijazi;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;
#Repository
public interface GradeRepository extends JpaRepository<Grade, Integer> {
}
Application.java
#SpringBootApplication
#RestController
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
#Autowired
private GradeRepository gradeRepo;
#RequestMapping(value="api/test")
public List<Grade> getall()
{
return gradeRepo.findAll();
}
}
application.properties
spring.jpa.hibernate.ddl-auto=validate
schema.sql
create table GRADE (id int not null, name varchar(20));
data.sql
insert into GRADE (id, name) values (2, 'name');
Dependencies in pom.xml
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>com.h2database</groupId>
<artifactId>h2</artifactId>
<scope>runtime</scope>
</dependency>
Now just run application and call this URL: http://localhost:8080/api/test
try to change the spring.jpa.hibernate.ddl-auto and see results
if you activate ddl-auto and have a schema.sql, BOTH of them are executed. But normally schema.sql is executed first. So the ddl-auto throws everything away, which was created by schema.sql and data.sql

Answer 2

After spending some time working through some ideas with #Safwan Hijazi in chat, came to the conclusion that what is happening is that the schema.sql and data.sql were being run but then the schema was recreated depending on the value (or lack of) of the spring.jpa.hibernate.ddl-auto property.
If not specified, spring/hibernate between them ended up recreating an empty schema (default seems to be create-drop for in memory DB).
If set the 'none' then that wouldn't happen and DB as created by the schema and data sql scripts would remain and the application functioned correctly.
See also: CrudRepository not reading data from schema.sql

Answer 3

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
Just gives you an spring boot opinionated inclusion to the spring-boot-starter-data-jpa maven file, for the bill of material of all the dependencies. To use any one of the dependency defined in the Dependency management of the spring-boot-starter-data-jpa pom you will have to explicitly declare the dependency in dependency section of your pom file.
<dependency>
<groupId>com.h2database</groupId>
<artifactId>h2</artifactId>
</dependency>
To get the h2 database up and running with your application, you can specifiy the properties in your application.properties file at src/main/resources/application.properties use:
spring.h2.console.enabled=true
spring.h2.console.path=/h2DB
so when you run your application with spring application starter, you will be able to access the application at http://localhost:8080/h2DB login to the DB and you can verify if the database had the inserts in it or not?
Don't find the data in there then you know where to make a change to keep the data there.