raviyasas

@Transactional
public List<Employee> getEmployees() {
    Connection connection = dataSource.getConnection(); 
    try (connection) {
        connection.setAutoCommit(false); 
        return employeeRepository.findAll();
        connection.commit(); 
    } catch (SQLException e) {
        connection.rollback(); 
    }

raviyasas

package com.app.sr.service;

import com.app.sr.entity.Customer;
import com.app.sr.repository.CustomerRepository;
import com.app.sr.util.model.ApiResponse;
import com.app.sr.util.model.ResponseBuilder;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Service;

raviyasas

package com.app.sr.controller;

import com.app.sr.service.CustomerService;
import com.app.sr.util.model.ApiResponse;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController

raviyasas

package com.app.sr.util.model;
import org.springframework.http.HttpHeaders;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Component;
import java.util.Map;

@Component
public class ResponseBuilder {

    public ResponseEntity <ApiResponse> buildResponse(

raviyasas

package com.app.sr.util.model;

import com.fasterxml.jackson.annotation.JsonPropertyOrder;
import org.springframework.http.HttpHeaders;
import org.springframework.http.ResponseEntity;

import java.util.Collections;
import java.util.Map;

@JsonPropertyOrder({ "httpHeaders", "httpStatusCode", "message", "data", "otherParams" })

raviyasas

package com.app.designPatterns.builder3;

public class Car {

    private final String make;
    private final Integer price;
    private final Boolean sunroof;
    private final Boolean alloyWheels;
    private final Boolean cruiseControl;
    private final Boolean electricSeats;

raviyasas

package com.app.designPatterns.builder1;

public class BuilderApp {

    public static void main(String[] args) {

        Phone iphone = new PhoneBuilder().setModel("Apple").setOs("IOS").buildPhone();
        System.out.println(iphone);

        Phone androidPhone = new PhoneBuilder().setModel("Nokia").setOs("Android").setCamera("32MP").buildPhone();

raviyasas

package com.app.designPatterns.singleton;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class SingletonDbManager {

    private static SingletonDbManager instance;
    private static Connection connection;

raviyasas

public enum EnumInit {
    instance;
}

raviyasas

public class ThreadSafe {

    private static volatile ThreadSafe instance;

    private ThreadSafe() {
        //  Avoid reflection API to create objects
        if(instance != null){
            throw new RuntimeException("Use getInstance method");
        }
    }