Category: spring Boot Jpa

Spring Boot JPA – Repository methods ”; Previous Next 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 public interface EmployeeRepository extends CrudRepository<Employee, Integer> { } Now this repository contains following methods by default. Sr.No Method & Description 1 count(): long returns the number of entities available. 2 delete(Employee entity): void deletes an entity. 3 deleteAll():void deletes all the entities. 4 deleteAll(Iterable< extends Employee > entities):void deletes the entities passed as argument. 5 deleteAll(Iterable< extends Integer > ids):void deletes the entities identified using their ids passed as argument. 6 existsById(Integer id):boolean checks if an entity exists using its id. 7 findAll():Iterable< Employee > returns all the entities. 8 findAllByIds(Iterable< Integer > ids):Iterable< Employee > returns all the entities identified using ids passed as argument. 9 findById(Integer id):Optional< Employee > returns an entity identified using id. 10 save(Employee entity): Employee saves an entity and return the updated one. 11 saveAll(Iterable< Employee> entities): Iterable< Employee> saves all entities passed and return the updated entities. Print Page Previous Next Advertisements ”;

Spring Boot JPA – Useful Resources ”; Previous Next The following resources contain additional information on Spring Boot JPA. Please use them to get more in-depth knowledge on this. Useful Links on Spring Boot JPA Official Website − Official Website of Spring Boot. Spring Framework − Wikipedia Reference for Spring Boot. Useful Books on Spring Boot JPA To enlist your site on this page, please drop an email to [email protected] Print Page Previous Next Advertisements ”;

Spring Boot JPA – Named Queries ”; Previous Next 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″) public class Employee { @Id @Column private int id; @Column private String name; @Column private int age; @Column private String email; 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 int getAge() { return age; } public void setAge(int age) { this.age = age; } public String getEmail() { return email; } public 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 public interface EmployeeRepository extends CrudRepository<Employee, Integer> { public List<Employee> findByName(String name); public List<Employee> findByAge(int age); public 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.SprintBootH2Application; @ExtendWith(SpringExtension.class) @Transactional @SpringBootTest(classes = SprintBootH2Application.class) public class EmployeeRepositoryTest { @Autowired private EmployeeRepository employeeRepository; @Test public void testFindById() { Employee employee = getEmployee(); employeeRepository.save(employee); Employee result = employeeRepository.findById(employee.getId()).get(); assertEquals(employee.getId(), result.getId()); } @Test public 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 public void testSave() { Employee employee = getEmployee(); employeeRepository.save(employee); Employee found = employeeRepository.findById(employee.getId()).get(); assertEquals(employee.getId(), found.getId()); } @Test public 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(“[email protected]”); return employee; } @Test public 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 public 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 public void testFindByEmail() { Employee employee = getEmployee(); employeeRepository.save(employee); Employee result = employeeRepository.findByEmail(employee.getEmail()); assertNotNull(result); } } Run the test cases Right Click on the file in eclipse and select Run a JUnit Test and verify the result. 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Discuss Spring Boot JPA ”; Previous Next 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. Spring Boot provides a seemless integration with JPA. Print Page Previous Next Advertisements ”;

Spring Boot JPA – Quick Guide ”; Previous Next 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 Earlier 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, Eclipse, etc. provide new products by adding the JPA persistence flavor in them. Some of these products include − Hibernate, Eclipselink, Toplink, 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, Eclipse 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 click 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-click on ”My Computer” and select ”Properties”. Click 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 Filesjavajdkbin. 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 line at the end − SET PATH=%PATH%;C:Program Filesjavajdkbin 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 line at the end of your .bashrc − export PATH=/path/to/java:$PATH” Alternatively, if you use an Integrated Development Environment (IDE) like Borland JBuilder, Eclipse, IntelliJ 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 Eclipse IDE All the examples in this tutorial have been written using Eclipse IDE. So we would suggest you should have the latest version of Eclipse installed on your machine. To install Eclipse IDE, download the latest Eclipse binaries from www.eclipse.org/downloads/. Once you download the installation, unpack the binary distribution into a convenient location. For example, in C:eclipse on Windows, or /usr/local/eclipse on Linux/Unix and finally set PATH variable appropriately. Eclipse can be started by executing the following commands on Windows machine, or you can simply double-click on eclipse.exe %C:eclipseeclipse.exe Eclipse can be started by executing the following commands on Unix (Solaris, Linux, etc.) machine − $/usr/local/eclipse/eclipse After a successful startup, if everything is fine then it should display the following result − Step 3 – Setup m2eclipse M2Eclipse is eclipse plugin which is very useful integration for Apache Maven into the Eclipse IDE. We are using maven in this tutorial to build spring boot project and examples are run within eclipse using m2eclipse. Install the latest M2Eclipse release by using the Install New Software dialog in Eclipse IDE,and point it to this p2 repository − https://download.eclipse.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 initializer link 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 click on GENERATE Button to generate the project structure. Once the maven based spring boot project is downloaded, then import the maven project into eclipse and rest eclipse 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

Spring Boot JPA Tutorial PDF Version Quick Guide Resources Job Search Discussion 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. Spring Boot provides a seemless integration with JPA. Audience This tutorial is designed for Java programmers who would like to understand the Spring Boot application to utilize JPA to connect to database in detail along with actual usage. Prerequisites Before proceeding with this tutorial, you should have a good understanding of Java programming language. As you are going to deal with a database, you should have prior exposure to RDBMS and Database concepts. Print Page Previous Next Advertisements ”;

Spring Boot JPA – Overview ”; Previous Next 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 Earlier 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, Eclipse, etc. provide new products by adding the JPA persistence flavor in them. Some of these products include − Hibernate, Eclipselink, Toplink, Spring Data JPA, etc. Print Page Previous Next Advertisements ”;

Spring Boot JPA – Environment Setup ”; Previous Next 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, Eclipse 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 click 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-click on ”My Computer” and select ”Properties”. Click 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 Filesjavajdkbin. 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 line at the end − SET PATH=%PATH%;C:Program Filesjavajdkbin 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 line at the end of your .bashrc − export PATH=/path/to/java:$PATH” Alternatively, if you use an Integrated Development Environment (IDE) like Borland JBuilder, Eclipse, IntelliJ 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 Eclipse IDE All the examples in this tutorial have been written using Eclipse IDE. So we would suggest you should have the latest version of Eclipse installed on your machine. To install Eclipse IDE, download the latest Eclipse binaries from www.eclipse.org/downloads/. Once you download the installation, unpack the binary distribution into a convenient location. For example, in C:eclipse on Windows, or /usr/local/eclipse on Linux/Unix and finally set PATH variable appropriately. Eclipse can be started by executing the following commands on Windows machine, or you can simply double-click on eclipse.exe %C:eclipseeclipse.exe Eclipse can be started by executing the following commands on Unix (Solaris, Linux, etc.) machine − $/usr/local/eclipse/eclipse After a successful startup, if everything is fine then it should display the following result − Step 3 – Setup m2eclipse M2Eclipse is eclipse plugin which is very useful integration for Apache Maven into the Eclipse IDE. We are using maven in this tutorial to build spring boot project and examples are run within eclipse using m2eclipse. Install the latest M2Eclipse release by using the Install New Software dialog in Eclipse IDE,and point it to this p2 repository − https://download.eclipse.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 initializer link 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 click on GENERATE Button to generate the project structure. Once the maven based spring boot project is downloaded, then import the maven project into eclipse and rest eclipse 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. Print Page Previous Next Advertisements ”;