springbootNotesAndRelatedSpring.md

@ConfigurationProperties -> will map properties file to pojo

@Component @ConfigurationProperties(prefix="myconfig") class myclass{ String appName; String appDesc; String appFirstName; }

application.yml

myconfig: app-name: My application Name appDesc: some app app-first-name: my first name

include some dependecy for this: spring-boot-configuration-processor

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program arguments: --spring.profiles.active=production -> its gonna override the defualt dev values.

=============================================================== application.properties spring.profiles.active=development

class DataSource {

String server; String port;

//empty constructor //settter getter //toString() to print }

@Configuration class DataSourceConfig {

@Bean("dataSource")
@Profile("development")
DataSource development(){
  return new DataSource("my-dev-url", 9999);
}

@Bean("dataSource")
@Profile("production")
DataSource production(){
  return new DataSource("my-prod-url", 8000);
}

}

@SpringBootApplication class App { psvm(String []args){ ApplicationContext ctx= SpringApplication.run(App.class, args); sout(ctx.getBean("dataSource").toString()); }

}

PRINT-> DataSource(server='my-dev-url',port=9999)

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with --debug option in program arguments, you can see which configuration got included in autoconfiguration and which got excluded from that

Security :

security.user.name=password security.user.password=password

dependency: spring-boot-starter-security

spring boot run with arguments

mvn spring-boot:run -Dspring-boot.run.arguments=-spring.profiles.active=production

OneToMany : one customer can have many products

@Data
@AllArgsConstructor
@NoArgsConstructor
@ToString
@Entity
public class Customer {
    @Id
    @GeneratedValue
    private int id;
    private String name;
    private String email;
    private String gender;
    @OneToMany(targetEntity = Product.class,cascade = CascadeType.ALL)
    @JoinColumn(name ="cp_fk",referencedColumnName = "id")
    private List<Product> products;
}

@Data
@AllArgsConstructor
@NoArgsConstructor
@ToString
@Entity
public class Product {
    @Id
    private int pid;
    private String productName;
    private int qty;
    private int price;
}

import java.util.List;

@RestController
public class OrderController {
    @Autowired
    private CustomerRepository customerRepository;
    @Autowired
    private ProductRepository productRepository;

    @PostMapping("/placeOrder")
    public Customer placeOrder(@RequestBody OrderRequest request){
       return customerRepository.save(request.getCustomer());
    }

    @GetMapping("/findAllOrders")
    public List<Customer> findAllOrders(){
        return customerRepository.findAll();
    }

    @GetMapping("/getInfo")
    public List<OrderResponse> getJoinInformation(){
        return customerRepository.getJoinInformation();
    }
}

if we save customer info, then product info will also get saved...

below is the ignore properties and include only non default.

@Data
@AllArgsConstructor
@NoArgsConstructor
@ToString
@JsonIgnoreProperties(ignoreUnknown = true)
@JsonInclude(JsonInclude.Include.NON_DEFAULT)
public class OrderResponse {

    private String name;
    private String productName;

    public OrderResponse(String name, String productName) {
        this.name = name;
        this.productName = productName;
    }

    private int price;
}