Create a simple REST web service using springboot.
Use spring initializer https://start.spring.io/
Dependencies
Web, JPA, database ( Mysql Connctor )
for your wish you can use, lombok, actuator, devtools
Webservice will include simple CRUD operation alias with REST POST,GET, PUT, GET
Tech Stack
Java 8, Maven, Springboot 3.10 ,
Sample code as below
POM file
<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>3.1.0</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.demo.micro</groupId>
<artifactId>student</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>student</name>
<description>Student Service</description>
<properties>
<java.version>17</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<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>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.31</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
Application properties
server.port=8203
spring.datasource.url=jdbc:mysql://localhost:3306/student_mgt
spring.datasource.username=root
spring.datasource.password=root
# for Spring Boot 2
# spring.jpa.properties.hibernate.dialect= org.hibernate.dialect.MySQL5InnoDBDialect
# for Spring Boot 3
spring.jpa.properties.hibernate.dialect= org.hibernate.dialect.MySQLDialect
spring.jpa.show-sql=false
spring.jpa.generate-ddl=true
# Hibernate ddl auto (create, create-drop, validate, update)
spring.jpa.hibernate.ddl-auto=update
spring.jpa.hibernate.naming.physical-strategy=org.hibernate.boot.model.naming.PhysicalNamingStrategyStandardImpl
Code base Structure
com.demo.micro.student
controller --> will include REST API
model --> model classes
repository --> repo file, db connection
service --> service classes
MainApllication --> StudentApplication with @SpringBootApplication
Controller
package com.demo.micro.student.controller;
import com.demo.micro.student.model.Student;
import com.demo.micro.student.service.StudentServiceImpl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import java.util.List;
import java.util.Optional;
@RestController
@RequestMapping("/students")
public class StudentController {
@Autowired
StudentServiceImpl studentService;
@GetMapping("")
public ResponseEntity<List<Student>> list() {
return new ResponseEntity<List<Student>>(studentService.list(), HttpStatus.OK);
}
@PostMapping("")
public ResponseEntity<Student> resgiterStudent(@RequestBody Student student) {
try {
Student st = studentService.createStudent(student);
return new ResponseEntity<>(st, HttpStatus.CREATED);
} catch (Exception e) {
return new ResponseEntity<>(null, HttpStatus.INTERNAL_SERVER_ERROR);
}
}
@PutMapping("")
public ResponseEntity<Student> updateStudent(@RequestBody Student student) {
return new ResponseEntity<>(studentService.createStudent(student), HttpStatus.OK);
}
@PutMapping("/{id}")
public ResponseEntity<Student> updateStudent(@PathVariable("id") int id, @RequestBody Student student) {
Optional<Student> st = studentService.findById(id);
if (st.isPresent()) {
// set details for student
return new ResponseEntity<>(studentService.createStudent(student), HttpStatus.OK);
} else {
return new ResponseEntity<>(HttpStatus.NOT_FOUND);
}
}
/**
* Don't do this. We normally makes a soft delete -
* 1. update flag/property as deleted. But flag is redundant field
* 2. use date/time option. nullable date time or default old time.
*
* @param student
* @return
*/
@DeleteMapping("")
public ResponseEntity<Student> deleteStudent(@RequestBody Student student) {
studentService.deleteStudent(student);
return new ResponseEntity<>(null, HttpStatus.ACCEPTED);
}
}
Model
package com.demo.micro.student.model;
import jakarta.persistence.*;
import lombok.Data;
/**
* Student details.
*/
@Entity
@Table(name = "student")
@Data
public class Student {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(name = "student_id")
private int studentId;
/**
* First name of the student.
*/
@Column(name = "first_name")
private String firstName;
/**
* Last name of the student.
*/
@Column(name = "last_name")
private String lastName;
}
Repository
package com.demo.micro.student.repository;
import com.demo.micro.student.model.Student;
import org.springframework.data.jpa.repository.JpaRepository;
public interface StudentRepository extends JpaRepository<Student,Integer> {
}
Service classes - Interface and Impl
package com.demo.micro.student.service;
import com.demo.micro.student.model.Student;
import java.util.List;
import java.util.Optional;
/**
*
*/
public interface StudentService {
/**
* Returns a list of {@link Student}s.
* @return list of {@link Student}
*/
List<Student> list();
Student createStudent(Student student);
Optional<Student> findById(int studentId);
void deleteStudent(Student student);
}
package com.demo.micro.student.service;
import com.demo.micro.student.model.Student;
import com.demo.micro.student.repository.StudentRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
import java.util.Optional;
@Service
public class StudentServiceImpl implements StudentService {
@Autowired
StudentRepository studentRepository;
/**
* List all the {@link Student}
*
* @return
*/
@Override
public List<Student> list() {
return studentRepository.findAll();
}
/**
* Create a new record of {@link Student}.
*
* @param student
* @return
*/
@Override
public Student createStudent(Student student) {
return studentRepository.save(student);
}
@Override
public Optional<Student> findById(int studentId) {
return studentRepository.findById(studentId);
}
public void deleteStudent(Student student) {
studentRepository.delete(student);
}
}
Important : Note that we put @Srvivie at Impl class, not Interface
Main class
package com.demo.micro.student;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class StudentApplication {
public static void main(String[] args) {
SpringApplication.run(StudentApplication.class, args);
}
}
