At present, the learning platform in the project has been set up DDD(domain driven design ) frame , I have a general idea , Classification chart :

Comments for each directory from top to bottom
/** * <p>Description: * DDD:application application layer *
Relative to domain layer , The application layer is very thin , The application defines the tasks to be accomplished by the software , Try to be as simple as possible * It doesn't contain any business rules or just , Assist tasks for next level domain objects , Commission work . *
It does not reflect the state of the business situation , But it can reflect the progress of a task of the user or program . * Responsible for context coordination , Provide various application functions for the presentation layer (service). *
Calling domain layer internally ( Domain object or domain service ) Complete various business logic tasks (event). * This layer is also suitable for writing tasks , Log monitoring . * </p> * * @author
xq.du * @version 1.0 * @date 2020-12-01 10:29 */
 
/** * <p>Description: * DDD:domain Domain layer * The domain layer is mainly responsible for expressing business concepts , Business status information and business rules . *
Domain Layer is the core layer of the whole system , Almost all of the business logic will be implemented in this layer . * The domain model layer mainly includes the following contents : * entity (entity): Object with unique identity . *
Value object (value object): Objects that do not require a unique identity . * Domain services (service): Some behaviors cannot be classified into entity objects or value objects , The essence is some operation , Not a business *
</p> * * @author xq.du * @version 1.0 * @date 2020-12-01 10:29 */
 
/** * <p>Description: * DDD:infrastructure Infrastructure layer , The bottom ( But interact with all the underlying layers ) *
Provide common technical capabilities to other layers ( For example, tools , Third party Treasury expenditure , Common basic configuration , Low level implementation of data access ) * The basic implementation layer mainly includes the following contents : * Delivering messages for the application layer *
Provide persistence mechanism for domain layer * Provides component configuration for the user interface layer * The infrastructure layer can also support the interaction mode among the four levels through the architecture framework . * </p> * * @author
xq.du * @version 1.0 * @date 2020-12-01 10:29 */
 
/** * <p>Description: * DDD:interface User interface layer ( Or presentation layer ) topmost . * Responsible for displaying information and explaining user commands to users . *
Request the application layer to obtain the data that users need to present ( For example, obtaining application system data ). * Send a command to the application layer and ask it to execute a user command ( Implement a business logic , For example, users add new application systems ). *
The user interface layer contains the following : * Data transfer object (data transfer object):DTO Also known as value objects , It is the carrier of data transmission , There should not be any business logic inside ,
* adopt DTO Isolate internal domain objects from the outside world . *
assembling (assembler): realization DTO Transformation between domain objects and domain objects , Data exchange , therefore assembler Almost always the same DTO Together . *
surface , Facade (facade):facade The purpose of is to provide a coarse-grained invocation interface for remote clients , Its main job is to delegate a user request *
Give one or more service Deal with it , It's also common controller. * </p> * * @author xq.du * @version 1.0 *
@date 2020-12-01 10:29 */
 

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