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Spring Boot CRUD Restful API with Oracle database
Quick Steps to Configure Spring Boot to use Oracle database
<!-- https://mvnrepository.com/artifact/com.oracle.jdbc/ojdbc8 --> <dependency> <groupId>com.oracle.jdbc</groupId> <artifactId>ojdbc8</artifactId> <version>12.2.0.1</version> </dependency>
# create and drop tables spring.jpa.hibernate.ddl-auto=create-drop # Oracle settings spring.datasource.url=jdbc:oracle:thin:@localhost:1521:xe spring.datasource.username=system spring.datasource.password=password spring.datasource.driver-class-name=oracle.jdbc.driver.OracleDriver
Let's develop a complete CRUD RESTFul APIs for a simple Employee Management System using Spring Boot, JPA/Hibernate, and Oracle database.
Tools and technologies used:
- Spring Boot - 2.0.4.RELEASE
- JDK - 1.8 or later
- Spring Framework - 5.0.8 RELEASE
- Hibernate - 5.2.17.Final
- Spring Data JPA
- Oracle database 11g express
- Oracle JDBC driver ojdbc8.jar
- Maven - 3.2+
- IDE - Eclipse or Spring Tool Suite (STS)
What we'll build
1. Creating and Importing a Project
>> Create Spring Boot Project in Spring Tool Suite [STS]
2. Packaging Structure
3. The pom.xml File
<!-- https://mvnrepository.com/artifact/com.oracle.jdbc/ojdbc8 -->
<dependency>
<groupId>com.oracle.jdbc</groupId>
<artifactId>ojdbc8</artifactId>
<version>12.2.0.1</version>
</dependency>
<?xml version="1.0" encoding="UTF-8"?>
<project
xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>net.guides.springboot2</groupId>
<artifactId>springboot2-jpa-crud-example</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>springboot2-jpa-crud-example</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.0.RELEASE</version>
<relativePath />
<!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<!-- https://mvnrepository.com/artifact/com.oracle.jdbc/ojdbc8 -->
<dependency>
<groupId>com.oracle.jdbc</groupId>
<artifactId>ojdbc8</artifactId>
<version>12.2.0.1</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
4. Oracle Database Configuration
# create and drop tables
spring.jpa.hibernate.ddl-auto=create-drop
# Oracle settings
spring.datasource.url=jdbc:oracle:thin:@localhost:1521:xe
spring.datasource.username=system
spring.datasource.password=password
spring.datasource.driver-class-name=oracle.jdbc.driver.OracleDriver
5. Create JPA Entity - Employee.java
package net.guides.springboot2.springboot2jpacrudexample.model; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.Table; @Entity @Table(name = "employees") public class Employee { private long id; private String firstName; private String lastName; private String emailId; public Employee() { } public Employee(String firstName, String lastName, String emailId) { this.firstName = firstName; this.lastName = lastName; this.emailId = emailId; } @Id @GeneratedValue(strategy = GenerationType.AUTO) public long getId() { return id; } public void setId(long id) { this.id = id; } @Column(name = "first_name", nullable = false) public String getFirstName() { return firstName; } public void setFirstName(String firstName) { this.firstName = firstName; } @Column(name = "last_name", nullable = false) public String getLastName() { return lastName; } public void setLastName(String lastName) { this.lastName = lastName; } @Column(name = "email_address", nullable = false) public String getEmailId() { return emailId; } public void setEmailId(String emailId) { this.emailId = emailId; } }
6. Create a Spring Data Repository - EmployeeRepository.java
package net.guides.springboot2.springboot2jpacrudexample.repository; import org.springframework.data.jpa.repository.JpaRepository; import org.springframework.stereotype.Repository; import net.guides.springboot2.springboot2jpacrudexample.model.Employee; @Repository public interface EmployeeRepository extends JpaRepository<Employee, Long>{ }
7. Create Spring Rest Controller - EmployeeController.java
package net.guides.springboot2.springboot2jpacrudexample.controller; import java.util.HashMap; import java.util.List; import java.util.Map; import javax.validation.Valid; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.http.ResponseEntity; import org.springframework.web.bind.annotation.CrossOrigin; 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 net.guides.springboot2.springboot2jpacrudexample.exception.ResourceNotFoundException; import net.guides.springboot2.springboot2jpacrudexample.model.Employee; import net.guides.springboot2.springboot2jpacrudexample.repository.EmployeeRepository; @RestController @RequestMapping("/api/v1") public class EmployeeController { @Autowired private EmployeeRepository employeeRepository; @GetMapping("/employees") public List < Employee > getAllEmployees() { return employeeRepository.findAll(); } @GetMapping("/employees/{id}") public ResponseEntity < Employee > getEmployeeById(@PathVariable(value = "id") Long employeeId) throws ResourceNotFoundException { Employee employee = employeeRepository.findById(employeeId) .orElseThrow(() -> new ResourceNotFoundException("Employee not found for this id :: " + employeeId)); return ResponseEntity.ok().body(employee); } @PostMapping("/employees") public Employee createEmployee(@Valid @RequestBody Employee employee) { return employeeRepository.save(employee); } @PutMapping("/employees/{id}") public ResponseEntity < Employee > updateEmployee(@PathVariable(value = "id") Long employeeId, @Valid @RequestBody Employee employeeDetails) throws ResourceNotFoundException { Employee employee = employeeRepository.findById(employeeId) .orElseThrow(() -> new ResourceNotFoundException("Employee not found for this id :: " + employeeId)); employee.setEmailId(employeeDetails.getEmailId()); employee.setLastName(employeeDetails.getLastName()); employee.setFirstName(employeeDetails.getFirstName()); final Employee updatedEmployee = employeeRepository.save(employee); return ResponseEntity.ok(updatedEmployee); } @DeleteMapping("/employees/{id}") public Map < String, Boolean > deleteEmployee(@PathVariable(value = "id") Long employeeId) throws ResourceNotFoundException { Employee employee = employeeRepository.findById(employeeId) .orElseThrow(() -> new ResourceNotFoundException("Employee not found for this id :: " + employeeId)); employeeRepository.delete(employee); Map < String, Boolean > response = new HashMap < > (); response.put("deleted", Boolean.TRUE); return response; } }
8. Exception(Error) Handling for RESTful Services
Resource Not Present
{
"timestamp": 1512713804164,
"status": 404,
"error": "Not Found",
"message": "No message available",
"path": "/some-dummy-url"
}
What happens when we throw an Exception?
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.ResponseStatus;
@ResponseStatus(value = HttpStatus.NOT_FOUND)
public class ResourceNotFoundException extends Exception{
private static final long serialVersionUID = 1L;
public ResourceNotFoundException(String message){
super(message);
}
}
Customizing Error Response Structure
import java.util.Date;
public class ErrorDetails {
private Date timestamp;
private String message;
private String details;
public ErrorDetails(Date timestamp, String message, String details) {
super();
this.timestamp = timestamp;
this.message = message;
this.details = details;
}
public Date getTimestamp() {
return timestamp;
}
public String getMessage() {
return message;
}
public String getDetails() {
return details;
}
}
import java.util.Date;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.context.request.WebRequest;
@ControllerAdvice
public class GlobalExceptionHandler {
@ExceptionHandler(ResourceNotFoundException.class)
public ResponseEntity<?> resourceNotFoundException(ResourceNotFoundException ex, WebRequest request) {
ErrorDetails errorDetails = new ErrorDetails(new Date(), ex.getMessage(), request.getDescription(false));
return new ResponseEntity<>(errorDetails, HttpStatus.NOT_FOUND);
}
@ExceptionHandler(Exception.class)
public ResponseEntity<?> globleExcpetionHandler(Exception ex, WebRequest request) {
ErrorDetails errorDetails = new ErrorDetails(new Date(), ex.getMessage(), request.getDescription(false));
return new ResponseEntity<>(errorDetails, HttpStatus.INTERNAL_SERVER_ERROR);
}
}
9. Running Application
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}
- @Configuration tags the class as a source of bean definitions for the application context.
- @EnableAutoConfiguration tells Spring Boot to start adding beans based on classpath settings, other beans, and various property settings.
- Normally you would add @EnableWebMvc for a Spring MVC app, but Spring Boot adds it automatically when it sees spring-webmvc on the classpath. This flags the application as a web application and activates key behaviors such as setting up a DispatcherServlet.
- @ComponentScan tells Spring to look for other components, configurations, and services in the hello package, allowing it to find the controllers.
10. Integration Testing for REST APIs
There is a separate beautiful article for integration testing for REST APIs on:
>> Spring Boot 2 REST APIs Integration Testing
once i kill the local server, the table doesnt exist only in the db. How is that possible?
ReplyDeletei can build successfully but when i want to run it, its throwing classnotfoundexception io.r2dbc.spi.connectionfactory
ReplyDeletewhere i'm wrong?
Thank you, Great tutorial all facts are correct......
ReplyDelete