tiennm99/java-design-patterns
1
0 Fork 0
mirror of https://github.com/tiennm99/java-design-patterns.git synced 2026-10-17 02:14:16 +00:00
Code Issues Packages Projects Releases Wiki Activity

docs: update dto

Browse Source
This commit is contained in:
Ilkka Seppälä committed 2024-05-25 11:29:35 +03:00
1 parent 08aafce66d
commit b855476315
1 file changed
+111 -26
Download Patch File Download Diff File Expand all files Collapse all files
data-transfer-object/README.md
+111 -26
View File
@@ -5,6 +5,7 @@ language: en
tag: tag:
- Client-server - Client-server
- Data transfer - Data transfer
- Decoupling
- Layered architecture - Layered architecture
- Optimization - Optimization
--- ---
@@ -20,9 +21,9 @@ The Data Transfer Object (DTO) pattern is used to transfer data between software
## Explanation ## Explanation
Real world example Real-world example
> Imagine you're at a grocery store with a long shopping list. Instead of calling a friend from every aisle to ask what's needed, you compile the entire list into one message and send it over. This is akin to a Data Transfer Object (DTO) in software, where instead of making multiple requests for data, a single, compiled set of data (like the complete shopping list) is transferred in one go, optimizing communication and efficiency. > Imagine a large company with several departments (e.g., Sales, HR, and IT) needing to share employee information efficiently. Instead of each department querying and retrieving data like name, address, and role individually, they use a courier service to bundle this data into a single package. This package, representing a Data Transfer Object (DTO), allows the departments to easily receive and process comprehensive employee data without making multiple requests. This simplifies data handling, reduces communication overhead, and ensures a standardized format across the company.
In plain words In plain words
@@ -55,30 +56,114 @@ public record CustomerResource(List<CustomerDto> customers) {
} }
``` ```
Now fetching customer information is easy since we have the DTOs. Now fetching customer information is easy since we have the DTOs. The 2nd example uses `ProductDTO` similarly.
```java ```java
var customerOne = new CustomerDto("1", "Kelly", "Brown"); public class App {
var customerTwo = new CustomerDto("2", "Alfonso", "Bass");
var customers = new ArrayList<>(List.of(customerOne, customerTwo)); public static void main(String[] args) {
var customerResource = new CustomerResource(customers);
LOGGER.info("All customers:"); // Example 1: Customer DTO
var allCustomers = customerResource.getCustomers(); var customerOne = new CustomerDto("1", "Kelly", "Brown");
printCustomerDetails(allCustomers); var customerTwo = new CustomerDto("2", "Alfonso", "Bass");
var customers = new ArrayList<>(List.of(customerOne, customerTwo));
var customerResource = new CustomerResource(customers);
LOGGER.info("All customers:");
var allCustomers = customerResource.customers();
printCustomerDetails(allCustomers);
LOGGER.info("----------------------------------------------------------");
LOGGER.info("Deleting customer with id {1}");
customerResource.delete(customerOne.id());
allCustomers = customerResource.customers();
printCustomerDetails(allCustomers);
LOGGER.info("----------------------------------------------------------");
LOGGER.info("Adding customer three}");
var customerThree = new CustomerDto("3", "Lynda", "Blair");
customerResource.save(customerThree);
allCustomers = customerResource.customers();
printCustomerDetails(allCustomers);
// Example 2: Product DTO
Product tv = Product.builder().id(1L).name("TV").supplier("Sony").price(1000D).cost(1090D).build();
Product microwave =
Product.builder()
.id(2L)
.name("microwave")
.supplier("Delonghi")
.price(1000D)
.cost(1090D).build();
Product refrigerator =
Product.builder()
.id(3L)
.name("refrigerator")
.supplier("Botsch")
.price(1000D)
.cost(1090D).build();
Product airConditioner =
Product.builder()
.id(4L)
.name("airConditioner")
.supplier("LG")
.price(1000D)
.cost(1090D).build();
List<Product> products =
new ArrayList<>(Arrays.asList(tv, microwave, refrigerator, airConditioner));
ProductResource productResource = new ProductResource(products);
LOGGER.info(
"####### List of products including sensitive data just for admins: \n {}",
Arrays.toString(productResource.getAllProductsForAdmin().toArray()));
LOGGER.info(
"####### List of products for customers: \n {}",
Arrays.toString(productResource.getAllProductsForCustomer().toArray()));
LOGGER.info("####### Going to save Sony PS5 ...");
ProductDto.Request.Create createProductRequestDto =
new ProductDto.Request.Create()
.setName("PS5")
.setCost(1000D)
.setPrice(1220D)
.setSupplier("Sony");
productResource.save(createProductRequestDto);
LOGGER.info(
"####### List of products after adding PS5: {}",
Arrays.toString(productResource.products().toArray()));
}
private static void printCustomerDetails(List<CustomerDto> allCustomers) {
allCustomers.forEach(customer -> LOGGER.info(customer.firstName()));
}
}
``` ```
The output will be: The console output:
``` ```
18:31:53.868 [main] INFO com.iluwatar.datatransfer.App -- All customers: 11:10:51.838 [main] INFO com.iluwatar.datatransfer.App -- All customers:
18:31:53.870 [main] INFO com.iluwatar.datatransfer.App -- Kelly 11:10:51.840 [main] INFO com.iluwatar.datatransfer.App -- Kelly
18:31:53.870 [main] INFO com.iluwatar.datatransfer.App -- Alfonso 11:10:51.840 [main] INFO com.iluwatar.datatransfer.App -- Alfonso
11:10:51.840 [main] INFO com.iluwatar.datatransfer.App -- ----------------------------------------------------------
11:10:51.840 [main] INFO com.iluwatar.datatransfer.App -- Deleting customer with id {1}
11:10:51.840 [main] INFO com.iluwatar.datatransfer.App -- Alfonso
11:10:51.840 [main] INFO com.iluwatar.datatransfer.App -- ----------------------------------------------------------
11:10:51.840 [main] INFO com.iluwatar.datatransfer.App -- Adding customer three}
11:10:51.840 [main] INFO com.iluwatar.datatransfer.App -- Alfonso
11:10:51.840 [main] INFO com.iluwatar.datatransfer.App -- Lynda
11:10:51.848 [main] INFO com.iluwatar.datatransfer.App -- ####### List of products including sensitive data just for admins:
[Private{id=1, name='TV', price=1000.0, cost=1090.0}, Private{id=2, name='microwave', price=1000.0, cost=1090.0}, Private{id=3, name='refrigerator', price=1000.0, cost=1090.0}, Private{id=4, name='airConditioner', price=1000.0, cost=1090.0}]
11:10:51.852 [main] INFO com.iluwatar.datatransfer.App -- ####### List of products for customers:
[Public{id=1, name='TV', price=1000.0}, Public{id=2, name='microwave', price=1000.0}, Public{id=3, name='refrigerator', price=1000.0}, Public{id=4, name='airConditioner', price=1000.0}]
11:10:51.852 [main] INFO com.iluwatar.datatransfer.App -- ####### Going to save Sony PS5 ...
11:10:51.856 [main] INFO com.iluwatar.datatransfer.App -- ####### List of products after adding PS5: [Product{id=1, name='TV', price=1000.0, cost=1090.0, supplier='Sony'}, Product{id=2, name='microwave', price=1000.0, cost=1090.0, supplier='Delonghi'}, Product{id=3, name='refrigerator', price=1000.0, cost=1090.0, supplier='Botsch'}, Product{id=4, name='airConditioner', price=1000.0, cost=1090.0, supplier='LG'}, Product{id=5, name='PS5', price=1220.0, cost=1000.0, supplier='Sony'}]
``` ```
## Class diagram
![DTO class diagram](./etc/data-transfer-object.urm.png "data-transfer-object")
## Applicability ## Applicability
Use the Data Transfer Object pattern when: Use the Data Transfer Object pattern when:
@@ -89,8 +174,9 @@ Use the Data Transfer Object pattern when:
## Tutorials ## Tutorials
* [Data Transfer Object Pattern in Java - Implementation and Mapping](https://stackabuse.com/data-transfer-object-pattern-in-java-implementation-and-mapping/) * [Data Transfer Object Pattern in Java - Implementation and Mapping (StackAbuse)](https://stackabuse.com/data-transfer-object-pattern-in-java-implementation-and-mapping/)
* [The DTO Pattern (Data Transfer Object)](https://www.baeldung.com/java-dto-pattern) * [Design Pattern - Transfer Object Pattern (TutorialsPoint)](https://www.tutorialspoint.com/design_pattern/transfer_object_pattern.htm)
* [The DTO Pattern (Baeldung)](https://www.baeldung.com/java-dto-pattern)
## Known Uses ## Known Uses
@@ -114,14 +200,13 @@ Trade-offs:
## Related Patterns ## Related Patterns
* [Service Layer](https://java-design-patterns.com/patterns/service-layer/): Often involves using DTOs to transfer data across the boundary between the service layer and its clients.
* [Facade](https://java-design-patterns.com/patterns/facade/): Similar to DTO, a Facade may aggregate multiple calls into one, improving efficiency.
* [Composite Entity](https://java-design-patterns.com/patterns/composite-entity/): DTOs may be used to represent composite entities, particularly in persistence mechanisms. * [Composite Entity](https://java-design-patterns.com/patterns/composite-entity/): DTOs may be used to represent composite entities, particularly in persistence mechanisms.
* [Facade](https://java-design-patterns.com/patterns/facade/): Similar to DTO, a Facade may aggregate multiple calls into one, improving efficiency.
* [Service Layer](https://java-design-patterns.com/patterns/service-layer/): Often involves using DTOs to transfer data across the boundary between the service layer and its clients.
## Credits ## Credits
* [Design Pattern - Transfer Object Pattern](https://www.tutorialspoint.com/design_pattern/transfer_object_pattern.htm)
* [Data Transfer Object](https://msdn.microsoft.com/en-us/library/ff649585.aspx)
* [J2EE Design Patterns](https://www.amazon.com/gp/product/0596004273/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596004273&linkCode=as2&tag=javadesignpat-20&linkId=f27d2644fbe5026ea448791a8ad09c94)
* [Patterns of Enterprise Application Architecture](https://www.amazon.com/gp/product/0321127420/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0321127420&linkCode=as2&tag=javadesignpat-20&linkId=014237a67c9d46f384b35e10151956bd)
* [Core J2EE Patterns: Best Practices and Design Strategies](https://amzn.to/4cKndQp) * [Core J2EE Patterns: Best Practices and Design Strategies](https://amzn.to/4cKndQp)
* [J2EE Design Patterns](https://amzn.to/4dpzgmx)
* [Patterns of Enterprise Application Architecture](https://amzn.to/3WfKBPR)
* [Data Transfer Object (Microsoft)](https://msdn.microsoft.com/en-us/library/ff649585.aspx)