mainul35

package com.mainul35.entity.order;

import com.fasterxml.jackson.annotation.JsonProperty;
import org.springframework.data.annotation.Id;
import org.springframework.data.mongodb.core.mapping.Document;
import org.springframework.data.mongodb.core.mapping.Field;

import java.math.BigDecimal;

/**

mainul35

version: '3.8'
services:
  bs-userinfo:
    container_name: 'bs-userinfo'
    image: 'bs-userinfo:1.0'
    build: ./
    ports:
      - '8581:8581'
    depends_on:
      - userinfo_db

mainul35

sudo docker run -p 5432:5432 \
-e POSTGRES_PASSWORD=123456 \
-e POSTGRES_HOST_AUTH_METHOD=trust \
--add-host=social_community:172.24.5.110 postgres

mainul35

1. Using Generics with wildcards
   • Unbounded wildcards
   • Bounded wildcards
     • Upper bounded wildcards
     • Lower bounded wildcards
2. Arrays with Generic types
3. Using Generic types as parameter of a class or an interface.
4. Using Generic types with method or constructor definition.

mainul35

public class StringClassesComparison {
    public static void main(String[] args) {
        String s = "";
        StringBuffer stringBuffer = new StringBuffer ("");
        StringBuilder stringBuilder = new StringBuilder ("");

        long millis = System.currentTimeMillis ();
        for (int i = 0; i < 10000; i++) {
            s += "something";
        }

mainul35

public class StackHeapUnderstanding {
    public static void main(String[] args) {
        int i1 = 10;
        int i2 = 10;
        Integer i3 = Integer.valueOf (10);

        System.out.println ("For int values: ");
        System.out.println (i1 == i2);
        System.out.println (i1 == i3);
        System.out.println (i3.equals (i1));

mainul35

@Repository
public interface ReservationRepository  extends ReactiveCrudRepository<Reservation, Long> {
    Mono<Reservation> getReservationByRoomId(Long roomId);
}

mainul35

@SpringBootApplication
public class ReactivespringApplication implements CommandLineRunner {

    @Autowired
    private DatabaseClient databaseClient;
    @Autowired
    private ReservationRepository reservationRepository;

    public static void main(String[] args) {
        SpringApplication.run(ReactivespringApplication.class, args);

mainul35

@Configuration
@EnableR2dbcRepositories(basePackages = "com.mainul35.repositories")
public class DatabaseConfig extends AbstractR2dbcConfiguration {

    @Value("${datasource.host}")
    private String host;
    @Value("${datasource.port}")
    private int port;
    @Value("${datasource.database}")
    private String database;

mainul35

```
# Database connection url: r2dbc:postgresql://host/bd_name
spring.r2dbc.url=r2dbc:postgresql://localhost/r2dbc_test
# Connection username
spring.r2dbc.username=postgres
# Connection Password
spring.r2dbc.password=
```