Tools & Techniques used:
Java
Maven
SpringBoot
RestApi
Derby database
The example illustrates the creation of an entity "user" and saves the data in the "users" table in derby.
crud operations: user: add, edit, serachById, del, hard-delete are demonstrated through rest APIs.
pom.xml
<dependencies>
<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>org.apache.derby</groupId>
<artifactId>derby</artifactId>
<version>10.13.1.1</version>
</dependency>
application.properties
spring.jpa.hibernate.ddl-auto=update
spring.jpa.generate-ddl=true
spring.jpa.show-sql=true
JpaConfig.java custom class to configure the data source
import javax.sql.DataSource;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
@Configuration
public class JpaConfig {
// primary Springboot datasource will be overwritten.
@Bean
public DataSource getDataSource() {
DataSourceBuilder dataSourceBuilder = DataSourceBuilder.create();
dataSourceBuilder.url("jdbc:derby:/Database/Derby/DB-Data;create=true");
//the database will be created at path c:/Database/Derby/DB-Data in windows
//bydefault userid/password are not required by derby though can be provided.
return dataSourceBuilder.build();
}
}
Entity class User.java
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
@Entity
@Table(name = "users")
public class User {
@Id
@Column(name = "id")
int id;
@Column(name = "userid")
String userid;
@Column(name = "password")
String password;
@Column(name = "role")
String role;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getUserid() {
return userid;
}
public void setUserid(String userid) {
this.userid = userid;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getRole() {
return role;
}
public void setRole(String role) {
this.role = role;
}
}
UserRepository.java
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;
import com.letUsLearn.entity.User;
@Repository
public interface UserRepository extends JpaRepository<User, Integer> {
}
UserService.java
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import com.letUsLearn.entity.User;
import com.letUsLearn.repositiry.UserRepository;
@Service
public class UserService {
@Autowired
UserRepository repository;
public User getUserById(int id) {
return repository.findById(id).get();
}
public User findById(int id) {
return repository.findById(id).get();
}
public List<User> findAll() {
return repository.findAll();
}
public User addUser(User user) {
return repository.save(user);
}
public User inactiveUser(int id) {
User user = getUserById(id);
if (user != null) {
user.setRole(null);
return repository.save(user);
}
return null;
}
public String delete(int id) {
User user = getUserById(id);
if (user != null) {
repository.delete(user);
return "deleted";
}
return "record not found";
}
}
UserControler,java
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.server.ResponseStatusException;
import com.letUsLearn.entity.User;
import com.letUsLearn.service.UserService;
@RestController
@RequestMapping("/user")
public class UserControler {
@Autowired
UserService service;
@RequestMapping(method = RequestMethod.GET, path = "/hello")
public String hello() {
return "hello:";
}
@RequestMapping(method = RequestMethod.GET, path = "/{id}")
public User getUserById(@PathVariable(value = "id") int id) {
try {
return service.findById(id);
} catch (Exception e) {
throw new ResponseStatusException(HttpStatus.NOT_FOUND);
}
}
@RequestMapping(method = RequestMethod.GET, path = "/list")
public List<User> getAllUsers() {
try {
return service.findAll();
} catch (Exception e) {
throw new ResponseStatusException(HttpStatus.NOT_FOUND);
}
}
@RequestMapping(method = RequestMethod.POST, path = "/add")
public User addUser(@RequestBody User user) {
try {
return service.addUser(user);
} catch (Exception e) {
throw new ResponseStatusException(HttpStatus.NOT_FOUND);
}
}
@RequestMapping(method = RequestMethod.GET, path = "/del/{id}")
public User inactiveUser(@PathVariable(value = "id") int id) {
try {
return service.inactiveUser(id);
} catch (Exception e) {
throw new ResponseStatusException(HttpStatus.NOT_FOUND);
}
}
@RequestMapping(method = RequestMethod.GET, path = "/del/{id}/hard")
public String delete(@PathVariable(value = "id") int id) {
try {
return service.delete(id);
} catch (Exception e) {
throw new ResponseStatusException(HttpStatus.NOT_FOUND);
}
}
}
the following JSON can be stored in a file and be imported to the postman.
SpringBootDerby.postman_collection.json
{
"variables": [],
"info": {
"name": "SpringBootDerby",
"_postman_id": "f5141a18-6b92-b381-7f0a-b76b237fb305",
"description": "",
"schema": "https://schema.getpostman.com/json/collection/v2.0.0/collection.json"
},
"item": [
{
"name": "http://localhost:8080/user/add 1st admin",
"request": {
"url": "http://localhost:8080/user/add",
"method": "POST",
"header": [
{
"key": "Content-Type",
"value": "application/json",
"description": ""
}
],
"body": {
"mode": "raw",
"raw": "{\r\n\t\"id\":\"1\",\r\n\t\"userid\":\"admin1\",\r\n\t\"password\":\"@#$\",\r\n\t\"role\":\"admin\"\r\n}"
},
"description": ""
},
"response": []
},
{
"name": "http://localhost:8080/user/add 2nd admin",
"request": {
"url": "http://localhost:8080/user/add",
"method": "POST",
"header": [
{
"key": "Content-Type",
"value": "application/json",
"description": ""
}
],
"body": {
"mode": "raw",
"raw": "{\r\n\t\"id\":\"2\",\r\n\t\"userid\":\"admin2\",\r\n\t\"password\":\"@#$\",\r\n\t\"role\":\"admin\"\r\n}"
},
"description": ""
},
"response": []
},
{
"name": "http://localhost:8080/user/add 1st Editor",
"request": {
"url": "http://localhost:8080/user/add",
"method": "POST",
"header": [
{
"key": "Content-Type",
"value": "application/json",
"description": ""
}
],
"body": {
"mode": "raw",
"raw": "{\r\n\t\"id\":\"3\",\r\n\t\"userid\":\"editor1\",\r\n\t\"password\":\"@#$\",\r\n\t\"role\":\"editor\"\r\n}"
},
"description": ""
},
"response": []
},
{
"name": "http://localhost:8080/user/add 2nd Editor",
"request": {
"url": "http://localhost:8080/user/add",
"method": "POST",
"header": [
{
"key": "Content-Type",
"value": "application/json",
"description": ""
}
],
"body": {
"mode": "raw",
"raw": "{\r\n\t\"id\":\"4\",\r\n\t\"userid\":\"editor2\",\r\n\t\"password\":\"@#$\",\r\n\t\"role\":\"editor\"\r\n}"
},
"description": ""
},
"response": []
},
{
"name": "http://localhost:8080/user/add 3rd Editor",
"request": {
"url": "http://localhost:8080/user/add",
"method": "POST",
"header": [
{
"key": "Content-Type",
"value": "application/json",
"description": ""
}
],
"body": {
"mode": "raw",
"raw": "{\r\n\t\"id\":\"5\",\r\n\t\"userid\":\"editor3\",\r\n\t\"password\":\"@#$\",\r\n\t\"role\":\"editor\"\r\n}"
},
"description": ""
},
"response": []
},
{
"name": "http://localhost:8080/user/1",
"request": {
"url": "http://localhost:8080/user/1",
"method": "GET",
"header": [],
"body": {},
"description": ""
},
"response": []
},
{
"name": "http://localhost:8080/user",
"request": {
"url": "http://localhost:8080/user/list",
"method": "GET",
"header": [],
"body": {},
"description": ""
},
"response": []
},
{
"name": "http://localhost:8080/user/del/5",
"request": {
"url": "http://localhost:8080/user/del/5",
"method": "GET",
"header": [],
"body": {},
"description": ""
},
"response": []
},
{
"name": "http://localhost:8080/user/del/5/hard",
"request": {
"url": "http://localhost:8080/user/del/5/hard",
"method": "GET",
"header": [],
"body": {},
"description": ""
},
"response": []
}
]
}
