somisettyv / venly_spring-boot-jpa-h2

spring-boot-jpa-h2

This Repo to demonstrate how to use the Spring Hibernate JPA works within Spring 4. This sample repo has few very simple UseCases such as adding new Employees to a deportment, retrieving all Employees from a given Department.

Anyone can leverage this as a Base Spring Boot App if you have simialar needs.

Build Capablities : Would work with Maven as well as Gradle

Key Capablities :

Using CRUP Repo interfaces which abstracts the Core java(hibernate) code that performs CRUD (Create, Read, Update, Delete) operations. public interface DepartmentRepository extends CrudRepository<Department, Long>

How to run :

H2 DB Set up :

Download H2 DB from http://www.h2database.com/html/download.html

Install H2 : 

Start H2  :

/Applications/AllMyProjects/h2/bin/h2.sh

Install Grandle

 https://gradle.org/install/

Install Maven

https://maven.apache.org/download.cgi

Run Spring Boot App:

 Go to the Souce code folder

 ./gradlew bootRun

Few Implementation Notes:

Add the following DB Driver details in Application.properties

         server.port=9093

        # create and drop tables and sequences, loads import.sql
        spring.jpa.hibernate.ddl-auto=update


        spring.datasource.username=
        spring.datasource.password=

        spring.datasource.name=test
        spring.datasource.driverClassName=org.h2.Driver

        spring.datasource.initialize=false
        spring.datasource.url=jdbc:h2:file:~/test;DB_CLOSE_ON_EXIT=FALSE;IFEXISTS=TRUE;DB_CLOSE_DELAY=-1;

        spring.jpa.hibernate.ddl-auto = update

DAO Layer :

 public interface DepartmentRepository extends CrudRepository<Department, Long>
 
 One to Many  : Department to Employee 
 
      @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER, mappedBy = "department")
  	  List<Employee> employees;
      
 Many to One   : 
     
     	@ManyToOne(fetch = FetchType.LAZY)
         @JoinColumn(name = "depno", nullable = false)
        Department department;