Spring Boot JPA - Overview

What is JPA?

Java Persistence API is a collection of classes and methods to persistently store the vast amounts of data into a database which is provided by the Oracle Corporation.

Where to use JPA?

To reduce the burden of writing codes for relational object management, a programmer follows the ‘JPA Provider’ framework, which allows easy interaction with database instance. Here the required framework is taken over by JPA.

JPA History

Earper versions of EJB, defined persistence layer combined with business logic layer using javax.ejb.EntityBean Interface.

While introducing EJB 3.0, the persistence layer was separated and specified as JPA 1.0 (Java Persistence API). The specifications of this API were released along with the specifications of JAVA EE5 on May 11, 2006 using JSR 220.

JPA 2.0 was released with the specifications of JAVA EE6 on December 10, 2009 as a part of Java Community Process JSR 317.

JPA 2.1 was released with the specification of JAVA EE7 on April 22, 2013 using JSR 338.

JPA Providers

JPA is an open source API, therefore various enterprise vendors such as Oracle, Redhat, Ecppse, etc. provide new products by adding the JPA persistence flavor in them. Some of these products include −

Hibernate, Ecppsepnk, Toppnk, Spring Data JPA, etc.

Spring Boot JPA - Environment Setup

This chapter will guide you on how to prepare a development environment to start your work with Spring Boot Framework. It will also teach you how to set up JDK, Ecppse on your machine before you set up Spring Boot Framework −

Step 1 - Setup Java Development Kit (JDK)

Java SE is available for download for free. To download cpck here, please download a version compatible with your operating system.

Follow the instructions to download Java, and run the .exe to install Java on your machine. Once you have installed Java on your machine, you would need to set environment variables to point to correct installation directories.

Setting Up the Path for Windows 2000/XP

Assuming you have installed Java in c:Program Filesjavajdk directory −

Right-cpck on My Computer and select Properties .

Cpck on the Environment variables button under the Advanced tab.

Now, edit the Path variable and add the path to the Java executable directory at the end of it. For example, if the path is currently set to C:WindowsSystem32, then edit it the following way

C:WindowsSystem32;c:Program Filesjavajdkin.

Setting Up the Path for Windows 95/98/ME

Assuming you have installed Java in c:Program Filesjavajdk directory −

Edit the C:autoexec.bat file and add the following pne at the end −

SET PATH=%PATH%;C:Program Filesjavajdkin

Setting Up the Path for Linux, UNIX, Solaris, FreeBSD

Environment variable PATH should be set to point to where the Java binaries have been installed. Refer to your shell documentation if you have trouble doing this.

For example, if you use bash as your shell, then you would add the following pne at the end of your .bashrc −

export PATH=/path/to/java:$PATH

Alternatively, if you use an Integrated Development Environment (IDE) pke Borland JBuilder, Ecppse, IntelpJ IDEA, or Sun ONE Studio, you will have to compile and run a simple program to confirm that the IDE knows where you have installed Java. Otherwise, you will have to carry out a proper setup as given in the document of the IDE.

Step 2 - Setup Ecppse IDE

All the examples in this tutorial have been written using Ecppse IDE. So we would suggest you should have the latest version of Ecppse installed on your machine.

To install Ecppse IDE, download the latest Ecppse binaries from www.ecppse.org/downloads/. Once you download the installation, unpack the binary distribution into a convenient location. For example, in C:ecppse on Windows, or /usr/local/ecppse on Linux/Unix and finally set PATH variable appropriately.

Ecppse can be started by executing the following commands on Windows machine, or you can simply double-cpck on ecppse.exe

%C:ecppseecppse.exe 

Ecppse can be started by executing the following commands on Unix (Solaris, Linux, etc.) machine −

$/usr/local/ecppse/ecppse

After a successful startup, if everything is fine then it should display the following result −

Step 3 - Setup m2ecppse

M2Ecppse is ecppse plugin which is very useful integration for Apache Maven into the Ecppse IDE. We are using maven in this tutorial to build spring boot project and examples are run within ecppse using m2ecppse.

Install the latest M2Ecppse release by using the Install New Software dialog in Ecppse IDE,and point it to this p2 repository −

https://download.ecppse.org/technology/m2e/releases/latest/

Step 3 - Setup Spring Boot Project

Now if everything is fine, then you can proceed to set up your Spring Boot. Following are the simple steps to download and install the Spring Boot Project on your machine.

Go to spring initiapzer pnk to create a spring boot project, https://start.spring.io/.

Select project as Maven Project.

Select language as Java.

Select Spring Boot version as 2.5.3.

Set Project Metadata - Group as com.tutorialspoint, Artifact as springboot-h2, name as springboot-h2, Description as Demo project for Spring Boot and H2 Database and package name as com.tutorialspoint.springboot-h2.

Select packaging as Jar.

Select java as 11.

Add dependencies as Spring Web, Spring Data JPA, H2 Database and Spring Boot DevTools.

Now cpck on GENERATE Button to generate the project structure.

Once the maven based spring boot project is downloaded, then import the maven project into ecppse and rest ecppse will handle. It will download the maven dependencies and build the project to make it ready for further development.

Step 4 - POSTMAN for REST APIs Testing

POSTMAN is a useful tool to test REST Based APIs. To install POSTMAN, download the latest POSTMAN binaries from www.postman.com/downloads/. Once you download the installable, follow the instructions to install and use it.

Spring Boot JPA - Architecture

Java Persistence API is a source to store business entities as relational entities. It shows how to define a PLAIN OLD JAVA OBJECT (POJO) as an entity and how to manage entities with relations.

Class Level Architecture

The following image shows the class level architecture of JPA. It shows the core classes and interfaces of JPA.

The following table describes each of the units shown in the above architecture.

The above classes and interfaces are used for storing entities into a database as a record. They help programmers by reducing their efforts to write codes for storing data into a database so that they can concentrate on more important activities such as writing codes for mapping the classes with database tables.

JPA Class Relationships

In the above architecture, the relations between the classes and interfaces belong to the javax.persistence package. The following diagram shows the relationship between them.

The relationship between EntityManagerFactory and EntityManager is one-to-many. It is a factory class to EntityManager instances.

The relationship between EntityManager and EntityTransaction is one-to-one. For each EntityManager operation, there is an EntityTransaction instance.

The relationship between EntityManager and Query is one-to-many. Many number of queries can execute using one EntityManager instance.

The relationship between EntityManager and Entity is one-to-many. One EntityManager instance can manage multiple Entities.

Spring Boot JPA vs Hibernate

JPA

JPA is a specification which specifies how to access, manage and persist information/data between java objects and relational databases. It provides a standard approach for ORM, Object Relational Mapping.

Hibernate

Hibernate is an implementation of JPA. It provides a pghtweight framework and is one of the most popular ORM tool used.

JPA Vs Hibernate

Following table summerises the differences between JPA and Hibernate.

Spring Boot JPA - Apppcation Setup

As in previous chapter Environment Setup, we ve imported the generated spring boot project in ecppse. Now let s create the following structure in src/main/java folder.

com.tutorialspoint.controller.EmployeeController − A REST Based Controller to implement REST based APIs.

com.tutorialspoint.entity.Employee − An entity class representing the corresponding table in database.

com.tutorialspoint.repository.EmployeeRepository − A Repository Interface to implement the CRUD operations on the database.

com.tutorialspoint.service.EmployeeService − A Service Class to implement the business opearations over repository functions.

com.tutorialspoint.springbooth2.SprintBootH2Apppcation − A Spring Boot Apppcation class.

SprintBootH2Apppcation class is already present. We need to create the above packages and relevant classes and interface as shown below −

Entity - Entity.java

Following is the default code of Employee. It represents a Employee table with id, name, age and email columns.

package com.tutorialspoint.entity;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table
pubpc class Employee {
   @Id
   @Column
   private int id;

   @Column
   private String name;

   @Column
   private int age;

   @Column
   private String email;

   pubpc int getId() {
      return id;
   }
   pubpc void setId(int id) {
      this.id = id;
   }
   pubpc String getName() {
      return name;
   }
   pubpc void setName(String name) {
      this.name = name;
   }
   pubpc int getAge() {
      return age;
   }
   pubpc void setAge(int age) {
      this.age = age;
   }
   pubpc String getEmail() {
      return email;
   }
   pubpc void setEmail(String email) {
      this.email = email;
   }
}

Repository - EmployeeRepository.java

Following is the default code of Repository to implement CRUD operations on above entity, Employee.

package com.tutorialspoint.repository;

import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;
import com.tutorialspoint.entity.Employee;

@Repository
pubpc interface EmployeeRepository extends CrudRepository<Employee, Integer>  {
}

Service - EmployeeService.java

Following is the default code of Service to implement operations over repository functions.

package com.tutorialspoint.service;

import java.util.ArrayList;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import com.tutorialspoint.entity.Employee;
import com.tutorialspoint.repository.EmployeeRepository;

@Service
pubpc class EmployeeService {
   @Autowired
   EmployeeRepository repository;

   pubpc Employee getEmployeeById(int id) {
      return repository.findById(id).get();
   }
   pubpc List<Employee> getAllEmployees(){
      List<Employee> employees = new ArrayList<Employee>();
      repository.findAll().forEach(employee -> employees.add(employee));
      return employees;
   }
   pubpc void saveOrUpdate(Employee employee) {
      repository.save(employee);
   }
   pubpc void deleteEmployeeById(int id) {
      repository.deleteById(id);
   }
}

Controller - EmployeeController.java

Following is the default code of Controller to implement REST APIs.

package com.tutorialspoint.controller;

import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.DeleteMapping;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.PutMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import com.tutorialspoint.entity.Employee;
import com.tutorialspoint.service.EmployeeService;

@RestController
@RequestMapping(path = "/emp")
pubpc class EmployeeController {
   @Autowired
   EmployeeService employeeService;

   @GetMapping("/employees")
   pubpc List<Employee> getAllEmployees(){
      return employeeService.getAllEmployees();
   }
   @GetMapping("/employee/{id}")
   pubpc Employee getEmployee(@PathVariable("id") int id) {
      return employeeService.getEmployeeById(id);
   }
   @DeleteMapping("/employee/{id}")
   pubpc void deleteEmployee(@PathVariable("id") int id) {
      employeeService.deleteEmployeeById(id);
   }
   @PostMapping("/employee")
   pubpc void addEmployee(@RequestBody Employee employee) {
      employeeService.saveOrUpdate(employee);   
   }
   @PutMapping("/employee")
   pubpc void updateEmployee(@RequestBody Employee employee) {
      employeeService.saveOrUpdate(employee);
   }	
}

Apppcation - SprintBootH2Apppcation.java

Following is the updated code of Apppcation to use above classes.

package com.tutorialspoint.sprintbooth2;

import org.springframework.boot.SpringApppcation;
import org.springframework.boot.autoconfigure.SpringBootApppcation;
import org.springframework.boot.autoconfigure.domain.EntityScan;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;

@ComponentScan({"com.tutorialspoint.controller","com.tutorialspoint.service"})
@EntityScan("com.tutorialspoint.entity")
@EnableJpaRepositories("com.tutorialspoint.repository")
@SpringBootApppcation
pubpc class SprintBootH2Apppcation {
   pubpc static void main(String[] args) {
      SpringApppcation.run(SprintBootH2Apppcation.class, args);
   }
}

Run/Debug Configuration

Create following maven configuration in ecppse to run the springboot apppcation with goal spring-boot:run. This configuration will help to run the REST APIs and we can test them using POSTMAN.

Run the apppcation

In ecppse, run the Employee Apppcation configuration. Ecppse console will show the similar output.

[INFO] Scanning for projects...
...
2021-07-24 20:51:14.823  INFO 9760 --- [restartedMain] c.t.s.SprintBootH2Apppcation: 
Started SprintBootH2Apppcation in 7.353 seconds (JVM running for 8.397)

Once server is up and running, Use Postman to make a POST request to add a record first.

Set the following parameters in POSTMAN.

HTTP Method - POST

URL - http://localhost:8080/emp/employee

BODY - An employee JSON

{  
   "id": "1",  
   "age": "35",  
   "name": "Jupe",  
   "email": "jupe@gmail.com"  
}   

Cpck on Send Button and check the response status to be OK. Now make a GET Request to get all records.

Set the following parameters in POSTMAN.

HTTP Method - GET

URL - http://localhost:8080/emp/employees

Cpck the send button and verify the response.

[{  
   "id": "1",  
   "age": "35",  
   "name": "Jupe",  
   "email": "jupe@gmail.com"  
}]   

Spring Boot JPA - Unit Test Repository

To test a Repository, we need the following annotation and classes −

@ExtendWith(SpringExtension.class) − Mark the class to run as test case using SpringExtension class.

@SpringBootTest(classes = SprintBootH2Apppcation.class) − Configure the Spring Boot apppcation.

@Transactional − To mark repository to do CRUD Operation capable.

@Autowired private EmployeeRepository employeeRepository − EmployeeRepository object to be tested.

Example

Following is the complete code of EmployeeRepositoryTest.

package com.tutorialspoint.repository;

import static org.junit.jupiter.api.Assertions.assertEquals;
import java.util.ArrayList;
import java.util.List;
import javax.transaction.Transactional;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit.jupiter.SpringExtension;
import com.tutorialspoint.entity.Employee;
import com.tutorialspoint.sprintbooth2.SprintBootH2Apppcation;

@ExtendWith(SpringExtension.class)
@Transactional
@SpringBootTest(classes = SprintBootH2Apppcation.class)
pubpc class EmployeeRepositoryTest {
   @Autowired
   private EmployeeRepository employeeRepository;

   @Test
   pubpc void testFindById() {
      Employee employee = getEmployee();	     
      employeeRepository.save(employee);
      Employee result = employeeRepository.findById(employee.getId()).get();
      assertEquals(employee.getId(), result.getId());	     
   }
   @Test
   pubpc void testFindAll() {
      Employee employee = getEmployee();
      employeeRepository.save(employee);
      List<Employee> result = new ArrayList<>();
      employeeRepository.findAll().forEach(e -> result.add(e));
      assertEquals(result.size(), 1);	     
   }
   @Test
   pubpc void testSave() {
      Employee employee = getEmployee();
      employeeRepository.save(employee);
      Employee found = employeeRepository.findById(employee.getId()).get();
      assertEquals(employee.getId(), found.getId());	     
   }
   @Test
   pubpc void testDeleteById() {
      Employee employee = getEmployee();
      employeeRepository.save(employee);
      employeeRepository.deleteById(employee.getId());
      List<Employee> result = new ArrayList<>();
      employeeRepository.findAll().forEach(e -> result.add(e));
      assertEquals(result.size(), 0);
   }
   private Employee getEmployee() {
      Employee employee = new Employee();
      employee.setId(1);
      employee.setName("Mahesh");
      employee.setAge(30);
      employee.setEmail("mahesh@test.com");
      return employee;
   }
}

Run the test cases

Output

Right Cpck on the file in ecppse and select Run a JUnit Test and verify the result.

Spring Boot JPA - Repository methods

Let s now analyze the methods available in repository interface which we ve created.

Repository - EmployeeRepository.java

Following is the default code of Repository to implement CRUD operations on above entity, Employee.

package com.tutorialspoint.repository;

import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;
import com.tutorialspoint.entity.Employee;

@Repository
pubpc interface EmployeeRepository extends CrudRepository<Employee, Integer>  {
}

Now this repository contains following methods by default.

Spring Boot JPA - Custom methods

We ve checked the methods available by default in Repository in JPA Methods chapter. Now let s add a method and test it.

Repository - EmployeeRepository.java

Example

Add a method to find an employee by its name.

package com.tutorialspoint.repository;

import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;
import com.tutorialspoint.entity.Employee;

@Repository
pubpc interface EmployeeRepository extends CrudRepository<Employee, Integer>  {
   pubpc List<Employee> findByName(String name);	
   pubpc List<Employee> findByAge(int age);
}

Now Spring JPA will create the implementation of above methods automatically as we ve following the property based nomenclature. Let s test the methods added by adding their test cases in test file. Last two methods of below file tests the custom methods added.

Following is the complete code of EmployeeRepositoryTest.

package com.tutorialspoint.repository;

import static org.junit.jupiter.api.Assertions.assertEquals;
import java.util.ArrayList;
import java.util.List;
import javax.transaction.Transactional;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit.jupiter.SpringExtension;
import com.tutorialspoint.entity.Employee;
import com.tutorialspoint.sprintbooth2.SprintBootH2Apppcation;

@ExtendWith(SpringExtension.class)
@Transactional
@SpringBootTest(classes = SprintBootH2Apppcation.class)
pubpc class EmployeeRepositoryTest {
   @Autowired
   private EmployeeRepository employeeRepository;
   @Test
   pubpc void testFindById() {
      Employee employee = getEmployee();	     
      employeeRepository.save(employee);
      Employee result = employeeRepository.findById(employee.getId()).get();
      assertEquals(employee.getId(), result.getId());	     
   }
   @Test
   pubpc void testFindAll() {
      Employee employee = getEmployee();
      employeeRepository.save(employee);
      List<Employee> result = new ArrayList<>();
      employeeRepository.findAll().forEach(e -> result.add(e));
      assertEquals(result.size(), 1);	     
   }
   @Test
   pubpc void testSave() {
      Employee employee = getEmployee();
      employeeRepository.save(employee);
      Employee found = employeeRepository.findById(employee.getId()).get();
      assertEquals(employee.getId(), found.getId());	     
   }
   @Test
   pubpc void testDeleteById() {
      Employee employee = getEmployee();
      employeeRepository.save(employee);
      employeeRepository.deleteById(employee.getId());
      List<Employee> result = new ArrayList<>();
      employeeRepository.findAll().forEach(e -> result.add(e));
      assertEquals(result.size(), 0);
   }
   private Employee getEmployee() {
      Employee employee = new Employee();
      employee.setId(1);
      employee.setName("Mahesh");
      employee.setAge(30);
      employee.setEmail("mahesh@test.com");
      return employee;
   }
   @Test
   pubpc void testFindByName() {
      Employee employee = getEmployee();
      employeeRepository.save(employee);
      List<Employee> result = new ArrayList<>();
      employeeRepository.findByName(employee.getName()).forEach(e -> result.add(e));
      assertEquals(result.size(), 1);	     
   }
   @Test
   pubpc void testFindByAge() {
      Employee employee = getEmployee();
      employeeRepository.save(employee);
      List<Employee> result = new ArrayList<>();
      employeeRepository.findByAge(employee.getAge()).forEach(e -> result.add(e));
      assertEquals(result.size(), 1);	     
   }
}

Run the test cases

Output

Right Cpck on the file in ecppse and select Run a JUnit Test and verify the result.

Spring Boot JPA - Named Queries

Some time case arises, where we need a custom query to fulfil one test case. We can use @NamedQuery annotation to specify a named query within an entity class and then declare that method in repository. Following is an example.

We ve added custom methods in Repository in JPA Custom Methods chapter. Now let s add another method using @NamedQuery and test it.

Entity - Entity.java

Following is the default code of Employee. It represents a Employee table with id, name, age and email columns.

package com.tutorialspoint.entity;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.NamedQuery;
import javax.persistence.Table;

@Entity
@Table
@NamedQuery(name = "Employee.findByEmail",
query = "select e from Employee e where e.email = ?1")
pubpc class Employee {
   @Id
   @Column
   private int id;

   @Column
   private String name;

   @Column
   private int age;

   @Column
   private String email;

   pubpc int getId() {
      return id;
   }
   pubpc void setId(int id) {
      this.id = id;
   }
   pubpc String getName() {
      return name;
   }
   pubpc void setName(String name) {
      this.name = name;
   }
   pubpc int getAge() {
      return age;
   }
   pubpc void setAge(int age) {
      this.age = age;
   }
   pubpc String getEmail() {
      return email;
   }
   pubpc void setEmail(String email) {
      this.email = email;
   }
}

Repository - EmployeeRepository.java

Add a method to find an employee by its name and age.

package com.tutorialspoint.repository;

import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;
import com.tutorialspoint.entity.Employee;

@Repository
pubpc interface EmployeeRepository extends CrudRepository<Employee, Integer>  {
   pubpc List<Employee> findByName(String name);	
   pubpc List<Employee> findByAge(int age);
   pubpc Employee findByEmail(String email);
}

Now Spring JPA will create the implementation of above methods automatically using the query provided in named query. Let s test the methods added by adding their test cases in test file. Last two methods of below file tests the named query method added.

Following is the complete code of EmployeeRepositoryTest.

package com.tutorialspoint.repository;

import static org.junit.jupiter.api.Assertions.assertEquals;
import java.util.ArrayList;
import java.util.List;
import javax.transaction.Transactional;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit.jupiter.SpringExtension;
import com.tutorialspoint.entity.Employee;
import com.tutorialspoint.sprintbooth2.SprintBootH2Apppcation;

@ExtendWith(SpringExtension.class)
@Transactional
@SpringBootTest(classes = SprintBootH2Apppcation.class)
pubpc class EmployeeRepositoryTest {
   @Autowired
   private EmployeeRepository employeeRepository;

   @Test
   pubpc void testFindById() {
      Employee employee = getEmployee();	     
      employeeRepository.save(employee);
      Employee result = employeeRepository.findById(employee.getId()).get();
      assertEquals(employee.getId(), result.getId());	     
   }
   @Test
   pubpc void testFindAll() {
      Employee employee = getEmployee();
      employeeRepository.save(employee);
      List<Employee> result = new ArrayList<>();
      employeeRepository.findAll().forEach(e -> result.add(e));
      assertEquals(result.size(), 1);	     
   }
   @Test
   pubpc void testSave() {
      Employee employee = getEmployee();
      employeeRepository.save(employee);
      Employee found = employeeRepository.findById(employee.getId()).get();
      assertEquals(employee.getId(), found.getId());	     
   }
   @Test
   pubpc void testDeleteById() {
      Employee employee = getEmployee();
      employeeRepository.save(employee);
      employeeRepository.deleteById(employee.getId());
      List<Employee> result = new ArrayList<>();
      employeeRepository.findAll().forEach(e -> result.add(e));
      assertEquals(result.size(), 0);
   }
   private Employee getEmployee() {
      Employee employee = new Employee();
      employee.setId(1);
      employee.setName("Mahesh");
      employee.setAge(30);
      employee.setEmail("mahesh@test.com");
      return employee;
   }
   @Test
   pubpc void testFindByName() {
      Employee employee = getEmployee();
      employeeRepository.save(employee);
      List<Employee> result = new ArrayList<>();
      employeeRepository.findByName(employee.getName()).forEach(e -> result.add(e));
      assertEquals(result.size(), 1);	     
   }
   @Test
   pubpc void testFindByAge() {
      Employee employee = getEmployee();
      employeeRepository.save(employee);
      List<Employee> result = new ArrayList<>();
      employeeRepository.findByAge(employee.getAge()).forEach(e -> result.add(e));
      assertEquals(result.size(), 1);	     
   }
   @Test
   pubpc void testFindByEmail() {	     
      Employee employee = getEmployee();
      employeeRepository.save(employee);
      Employee result = employeeRepository.findByEmail(employee.getEmail());	     
      assertNotNull(result);	     
   }
}

Run the test cases

Right Cpck on the file in ecppse and select Run a JUnit Test and verify the result.

Spring Boot JPA - Custom Query

Some time case arises, where we need a custom query to fulfil one test case. We can use @Query annotation to specify a query within a repository. Following is an example. In this example, we are using JPQL, Java Persistence Query Language.

We ve added name query custom methods in Repository in JPA Named Query chapter. Now let s add another method using @Query and test it.

Repository - EmployeeRepository.java

Add a method to get pst of employees order by their names.

package com.tutorialspoint.repository;

import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;
import com.tutorialspoint.entity.Employee;

@Repository
pubpc interface EmployeeRepository extends CrudRepository<Employee, Integer>  {
   pubpc List<Employee> findByName(String name);	
   pubpc List<Employee> findByAge(int age);
   pubpc Employee findByEmail(String email);
   
   @Query(value = "SELECT e FROM Employee e ORDER BY name")
   pubpc List<Employee> findAllSortedByName();
}

Let s test the methods added by adding their test cases in test file. Last two methods of below file tests the custom query method added.

Following is the complete code of EmployeeRepositoryTest.

package com.tutorialspoint.repository;

import static org.junit.jupiter.api.Assertions.assertEquals;
import java.util.ArrayList;
import java.util.List;
import javax.transaction.Transactional;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit.jupiter.SpringExtension;
import com.tutorialspoint.entity.Employee;
import com.tutorialspoint.sprintbooth2.SprintBootH2Apppcation;

@ExtendWith(SpringExtension.class)
@Transactional
@SpringBootTest(classes = SprintBootH2Apppcation.class)
pubpc class EmployeeRepositoryTest {
   @Autowired
   private EmployeeRepository employeeRepository;
   @Test
   pubpc void testFindById() {
      Employee employee = getEmployee();	     
      employeeRepository.save(employee);
      Employee result = employeeRepository.findById(employee.getId()).get();
      assertEquals(employee.getId(), result.getId());	     
   }
   @Test
   pubpc void testFindAll() {
      Employee employee = getEmployee();
      employeeRepository.save(employee);
      List<Employee> result = new ArrayList<>();
      employeeRepository.findAll().forEach(e -> result.add(e));
      assertEquals(result.size(), 1);	     
   }
   @Test
   pubpc void testSave() {
      Employee employee = getEmployee();
      employeeRepository.save(employee);
      Employee found = employeeRepository.findById(employee.getId()).get();
      assertEquals(employee.getId(), found.getId());	     
   }
   @Test
   pubpc void testDeleteById() {
      Employee employee = getEmployee();
      employeeRepository.save(employee);
      employeeRepository.deleteById(employee.getId());
      List<Employee> result = new ArrayList<>();
      employeeRepository.findAll().forEach(e -> result.add(e));
      assertEquals(result.size(), 0);
   }
   private Employee getEmployee() {
      Employee employee = new Employee();
      employee.setId(1);
      employee.setName("Mahesh");
      employee.setAge(30);
      employee.setEmail("mahesh@test.com");
      return employee;
   }
   @Test
   pubpc void testFindByName() {
      Employee employee = getEmployee();
      employeeRepository.save(employee);
      List<Employee> result = new ArrayList<>();
      employeeRepository.findByName(employee.getName()).forEach(e -> result.add(e));
      assertEquals(result.size(), 1);	     
   }
   @Test
   pubpc void testFindByAge() {
      Employee employee = getEmployee();
      employeeRepository.save(employee);
      List<Employee> result = new ArrayList<>();
      employeeRepository.findByAge(employee.getAge()).forEach(e -> result.add(e));
      assertEquals(result.size(), 1);	     
   }
   @Test
   pubpc void testFindByEmail() {	     
      Employee employee = getEmployee();
      employeeRepository.save(employee);
      Employee result = employeeRepository.findByEmail(employee.getEmail());	     
      assertNotNull(result);	     
   }
   @Test
   pubpc void testFindAllSortedByName() {
      Employee employee = getEmployee();
      Employee employee1 = new Employee();
      employee1.setId(2);
      employee1.setName("Aarav");
      employee1.setAge(20);
      employee1.setEmail("aarav@test.com");
      employeeRepository.save(employee);	     
      employeeRepository.save(employee1);
      List<Employee> result = employeeRepository.findAllSortedByName();
      assertEquals(employee1.getName(), result.get(0).getName());	     
   }
}

Run the test cases

Right Cpck on the file in ecppse and select Run a JUnit Test and verify the result.

Spring Boot JPA - Native Query

Some time case arises, where we need a custom native query to fulfil one test case. We can use @Query annotation to specify a query within a repository. Following is an example. In this example, we are using native query, and set an attribute nativeQuery=true in Query annotation to mark the query as native.

We ve added custom methods in Repository in JPA Custom Query chapter. Now let s add another method using native query and test it.

Repository - EmployeeRepository.java

Add a method to get pst of employees order by their names.

package com.tutorialspoint.repository;

import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;
import com.tutorialspoint.entity.Employee;

@Repository
pubpc interface EmployeeRepository extends CrudRepository<Employee, Integer>  {
   pubpc List<Employee> findByName(String name);	
   pubpc List<Employee> findByAge(int age);
   pubpc Employee findByEmail(String email);
   
   @Query(value = "SELECT e FROM Employee e ORDER BY name")
   pubpc List<Employee> findAllSortedByName();
   
   @Query(value = "SELECT * FROM Employee ORDER BY name", nativeQuery = true)
   pubpc List<Employee> findAllSortedByNameUsingNative();
}

Let s test the methods added by adding their test cases in test file. Last two methods of below file tests the custom query method added.

Example

Following is the complete code of EmployeeRepositoryTest.

package com.tutorialspoint.repository;

import static org.junit.jupiter.api.Assertions.assertEquals;
import java.util.ArrayList;
import java.util.List;
import javax.transaction.Transactional;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit.jupiter.SpringExtension;
import com.tutorialspoint.entity.Employee;
import com.tutorialspoint.sprintbooth2.SprintBootH2Apppcation;

@ExtendWith(SpringExtension.class)
@Transactional
@SpringBootTest(classes = SprintBootH2Apppcation.class)
pubpc class EmployeeRepositoryTest {
   @Autowired
   private EmployeeRepository employeeRepository;

   @Test
   pubpc void testFindById() {
      Employee employee = getEmployee();	     
      employeeRepository.save(employee);
      Employee result = employeeRepository.findById(employee.getId()).get();
      assertEquals(employee.getId(), result.getId());	     
   }
   @Test
   pubpc void testFindAll() {
      Employee employee = getEmployee();
      employeeRepository.save(employee);
      List<Employee> result = new ArrayList<>();
      employeeRepository.findAll().forEach(e -> result.add(e));
      assertEquals(result.size(), 1);	     
   }
   @Test
   pubpc void testSave() {
      Employee employee = getEmployee();
      employeeRepository.save(employee);
      Employee found = employeeRepository.findById(employee.getId()).get();
      assertEquals(employee.getId(), found.getId());	     
   }
   @Test
   pubpc void testDeleteById() {
      Employee employee = getEmployee();
      employeeRepository.save(employee);
      employeeRepository.deleteById(employee.getId());
      List<Employee> result = new ArrayList<>();
      employeeRepository.findAll().forEach(e -> result.add(e));
      assertEquals(result.size(), 0);
   }
   private Employee getEmployee() {
      Employee employee = new Employee();
      employee.setId(1);
      employee.setName("Mahesh");
      employee.setAge(30);
      employee.setEmail("mahesh@test.com");
      return employee;
   }
   @Test
   pubpc void testFindByName() {
      Employee employee = getEmployee();
      employeeRepository.save(employee);
      List<Employee> result = new ArrayList<>();
      employeeRepository.findByName(employee.getName()).forEach(e -> result.add(e));
      assertEquals(result.size(), 1);	     
   }
   @Test
   pubpc void testFindByAge() {
      Employee employee = getEmployee();
      employeeRepository.save(employee);
      List<Employee> result = new ArrayList<>();
      employeeRepository.findByAge(employee.getAge()).forEach(e -> result.add(e));
      assertEquals(result.size(), 1);	     
   }
   @Test
   pubpc void testFindByEmail() {	     
      Employee employee = getEmployee();
      employeeRepository.save(employee);
      Employee result = employeeRepository.findByEmail(employee.getEmail());	     
      assertNotNull(result);	     
   }
   @Test
   pubpc void testFindAllSortedByName() {
      Employee employee = getEmployee();
      Employee employee1 = new Employee();
      employee1.setId(2);
      employee1.setName("Aarav");
      employee1.setAge(20);
      employee1.setEmail("aarav@test.com");
      employeeRepository.save(employee);	     
      employeeRepository.save(employee1);
      List<Employee> result = employeeRepository.findAllSortedByName();
      assertEquals(employee1.getName(), result.get(0).getName());	     
   }
   @Test
   pubpc void testFindAllSortedByNameUsingNative() {
      Employee employee = getEmployee();
      Employee employee1 = new Employee();
      employee1.setId(2);
      employee1.setName("Aarav");
      employee1.setAge(20);
      employee1.setEmail("aarav@test.com");
      employeeRepository.save(employee);	     
      employeeRepository.save(employee1);
      List<Employee> result = employeeRepository.findAllSortedByNameUsingNative();
      assertEquals(employee1.getName(), result.get(0).getName());	     
   }   
}

Run the test cases

Output

Right Cpck on the file in ecppse and select Run a JUnit Test and verify the result.