Resync

abstract-document/README.md

@@ -5,8 +5,7 @@ folder: abstract-document
 permalink: /patterns/abstract-document/
 categories: Structural
 tags: 
- - Java
- - Difficulty-Intermediate
+ - Extensibility
 ---
 
 ## Intent

abstract-factory/README.md

@@ -5,9 +5,7 @@ folder: abstract-factory
 permalink: /patterns/abstract-factory/
 categories: Creational
 tags:
- - Java
- - Gang Of Four
- - Difficulty-Intermediate
+ - Gang of Four
 ---
 
 ## Also known as

acyclic-visitor/README.md

@@ -5,8 +5,7 @@ folder: acyclic-visitor
 permalink: /patterns/acyclic-visitor/
 categories: Behavioral
 tags:
- - Java
- - Difficulty-Intermediate
+ - Extensibility
 ---
 
 ## Intent

adapter/README.md

@@ -5,9 +5,7 @@ folder: adapter
 permalink: /patterns/adapter/
 categories: Structural
 tags:
- - Java
- - Gang Of Four
- - Difficulty-Beginner
+ - Gang of Four
 ---
 
 ## Also known as

aggregator-microservices/README.md

@@ -5,8 +5,7 @@ folder: aggregator-microservices
 permalink: /patterns/aggregator-microservices/
 categories: Architectural
 tags:
-- Java
-- Spring
+- Cloud distributed
 ---
 
 ## Intent

ambassador/README.md

@@ -5,8 +5,7 @@ folder: ambassador
 permalink: /patterns/ambassador/
 categories: Structural
 tags:
- - Java
- - Difficulty-Intermediate
+ - Decoupling
 ---
 
 ## Intent

api-gateway/README.md

@@ -5,9 +5,8 @@ folder: api-gateway
 permalink: /patterns/api-gateway/
 categories: Architectural
 tags:
-- Java
-- Difficulty-Intermediate
-- Spring
+- Cloud distributed
+- Decoupling
 ---
 
 ## Intent

async-method-invocation/README.md

@@ -5,9 +5,6 @@ folder: async-method-invocation
 permalink: /patterns/async-method-invocation/
 categories: Concurrency
 tags:
- - Java
- - Difficulty-Intermediate
- - Functional
  - Reactive
 ---
 

balking/README.md

@@ -5,8 +5,7 @@ folder: balking
 permalink: /patterns/balking/
 categories: Concurrency
 tags:
- - Java
- - Difficulty-Beginner
+ - Decoupling
 ---
 
 ## Intent

bridge/README.md

@@ -5,9 +5,7 @@ folder: bridge
 permalink: /patterns/bridge/
 categories: Structural
 tags:
- - Java
- - Gang Of Four
- - Difficulty-Intermediate
+ - Gang of Four
 ---
 
 ## Also known as

builder/README.md

@@ -5,9 +5,7 @@ folder: builder
 permalink: /patterns/builder/
 categories: Creational
 tags:
- - Java
- - Gang Of Four
- - Difficulty-Intermediate
+ - Gang of Four
 ---
 
 ## Intent

business-delegate/README.md

@@ -3,10 +3,9 @@ layout: pattern
 title: Business Delegate
 folder: business-delegate
 permalink: /patterns/business-delegate/
-categories: Business Tier
+categories: Structural
 tags:
- - Java
- - Difficulty-Intermediate
+ - Decoupling
 ---
 
 ## Intent

bytecode/README.md

@@ -5,8 +5,7 @@ folder: bytecode
 permalink: /patterns/bytecode/
 categories: Behavioral
 tags:
- - Java
- - Difficulty-Beginner
+ - Game programming
 ---
 
 ## Intent

caching/README.md

@@ -3,10 +3,8 @@ layout: pattern
 title: Caching
 folder: caching
 permalink: /patterns/caching/
-categories: Other
+categories: Behavioral
 tags:
- - Java
- - Difficulty-Intermediate
  - Performance
 ---
 

callback/README.md

@@ -3,12 +3,9 @@ layout: pattern
 title: Callback
 folder: callback
 permalink: /patterns/callback/
-categories: Other
+categories: Idiom
 tags:
- - Java
- - Difficulty-Beginner
- - Functional
- - Idiom
+ - Reactive
 ---
 
 ## Intent

chain/README.md

@@ -5,9 +5,7 @@ folder: chain
 permalink: /patterns/chain/
 categories: Behavioral
 tags:
- - Java
- - Gang Of Four
- - Difficulty-Intermediate
+ - Gang of Four
 ---
 
 ## Intent

circuit-breaker/README.md

@@ -3,11 +3,10 @@ layout: pattern
 title: Circuit Breaker
 folder: circuit-breaker
 permalink: /patterns/circuit-breaker/
-categories: Other
+categories: Behavioral
 tags:
- - Java
  - Performance
- - Difficulty-Intermediate
+ - Decoupling
 ---
 
 ## Intent
@@ -179,6 +178,7 @@ Use the Circuit Breaker pattern when
 - [Retry Pattern](https://github.com/iluwatar/java-design-patterns/tree/master/retry)
 
 ## Real world examples
+
 * [Spring Circuit Breaker module](https://spring.io/guides/gs/circuit-breaker)
 * [Netflix Hystrix API](https://github.com/Netflix/Hystrix)
 

collection-pipeline/README.md

@@ -3,11 +3,9 @@ layout: pattern
 title: Collection Pipeline
 folder: collection-pipeline
 permalink: /patterns/collection-pipeline/
-categories: Other
+categories: Functional
 tags:
- - Java
- - Difficulty-Beginner
- - Functional
+ - Reactive
 ---
 
 ## Intent
@@ -28,4 +26,4 @@ Use the Collection Pipeline pattern when
 
 * [Function composition and the Collection Pipeline pattern](https://www.ibm.com/developerworks/library/j-java8idioms2/index.html)
 * [Martin Fowler](https://martinfowler.com/articles/collection-pipeline/)
-* [Java8 Streams](https://docs.oracle.com/javase/8/docs/api/java/util/stream/package-summary.html)
+* [Java8 Streams](https://docs.oracle.com/javase/8/docs/api/java/util/stream/package-summary.html)

combinator/README.md

@@ -3,11 +3,9 @@ layout: pattern
 title: Combinator
 folder: combinator
 permalink: /patterns/combinator/
-categories: Behavioral
+categories: Idiom
 tags:
- - Functional
  - Reactive
- - Idiom
 ---
 
 ## Also known as
@@ -23,13 +21,16 @@ and some "combinators" which can combine values of type T in various ways to bui
 
 ## Applicability
 Use the combinator pattern when:
+
 - You are able to create a more complex value from more plain values but having the same type(a combination of them)
 
 ## Real world examples
+
 - java.util.function.Function#compose
 - java.util.function.Function#andThen
 
 ## Credits
+
 - [Example for java](https://gtrefs.github.io/code/combinator-pattern/)
 - [Combinator pattern](https://wiki.haskell.org/Combinator_pattern)
-- [Combinatory logic](https://wiki.haskell.org/Combinatory_logic)
+- [Combinatory logic](https://wiki.haskell.org/Combinatory_logic)

command/README.md

@@ -5,10 +5,7 @@ folder: command
 permalink: /patterns/command/
 categories: Behavioral
 tags:
- - Java
- - Gang Of Four
- - Difficulty-Intermediate
- - Functional
+ - Gang of Four
 ---
 
 ## Also known as

commander/README.md

@@ -3,10 +3,9 @@ layout: pattern
 title: Commander
 folder: commander
 permalink: /patterns/commander/
-categories: Other
+categories: Concurrency
 tags:
- - Java
- - Difficulty-Intermediate
+ - Cloud distributed
 ---
 
 ## Intent
@@ -24,4 +23,5 @@ Handling distributed transactions can be tricky, but if we choose to not handle
 We need a mechanism in place which can handle these kinds of situations. We have to direct the order to either one of the services (in this example, shipping) and then add the order into the database of the other service (in this example, payment), since two databses cannot be updated atomically. If currently unable to do it, there should be a queue where this request can be queued, and there has to be a mechanism which allows for a failure in the queueing as well. All this needs to be done by constant retries while ensuring idempotence (even if the request is made several times, the change should only be applied once) by a commander class, to reach a state of eventual consistency.
 
 ## Credits
+
 * [https://www.grahamlea.com/2016/08/distributed-transactions-microservices-icebergs/]

composite/README.md

@@ -5,9 +5,7 @@ folder: composite
 permalink: /patterns/composite/
 categories: Structural
 tags:
- - Java
- - Gang Of Four
- - Difficulty-Intermediate
+ - Gang of Four
 ---
 
 ## Intent

converter/README.md

@@ -3,10 +3,9 @@ layout: pattern
 title: Converter
 folder: converter
 permalink: /patterns/converter/
-categories: Business Tier
+categories: Creational
 tags:
- - Java
- - Difficulty-Beginner
+ - Decoupling
 ---
 
 ## Intent
@@ -64,20 +63,26 @@ The specialized converters inherit from this base class as follows.
 public class UserConverter extends Converter<UserDto, User> {
 
   public UserConverter() {
-    super(userDto -> new User(userDto.getFirstName(), userDto.getLastName(), userDto.isActive(),
-            userDto.getEmail()),
-        user -> new UserDto(user.getFirstName(), user.getLastName(), user.isActive(),
-            user.getUserId()));
+    super(UserConverter::convertToEntity, UserConverter::convertToDto);
   }
+
+  private static UserDto convertToDto(User user) {
+    return new UserDto(user.getFirstName(), user.getLastName(), user.isActive(), user.getUserId());
+  }
+
+  private static User convertToEntity(UserDto dto) {
+    return new User(dto.getFirstName(), dto.getLastName(), dto.isActive(), dto.getEmail());
+  }
+
 }
 ```
 
 Now mapping between User and UserDto becomes trivial.
 
 ```java
-Converter<UserDto, User> userConverter = new UserConverter();
-UserDto dtoUser = new UserDto("John", "Doe", true, "whatever[at]wherever.com");
-User user = userConverter.convertFromDto(dtoUser);
+var userConverter = new UserConverter();
+var dtoUser = new UserDto("John", "Doe", true, "whatever[at]wherever.com");
+var user = userConverter.convertFromDto(dtoUser);
 ```
 
 ## Class diagram

converter/src/main/java/com/iluwatar/converter/App.java

@@ -49,8 +49,11 @@ public static void main(String[] args) {
     User user = userConverter.convertFromDto(dtoUser);
     LOGGER.info("Entity converted from DTO:" + user);
 
-    var users = List.of(new User("Camile", "Tough", false, "124sad"),
-        new User("Marti", "Luther", true, "42309fd"), new User("Kate", "Smith", true, "if0243"));
+    var users = List.of(
+        new User("Camile", "Tough", false, "124sad"),
+        new User("Marti", "Luther", true, "42309fd"),
+        new User("Kate", "Smith", true, "if0243")
+    );
     LOGGER.info("Domain entities:");
     users.stream().map(User::toString).forEach(LOGGER::info);
 

converter/src/main/java/com/iluwatar/converter/User.java

@@ -73,7 +73,7 @@ public boolean equals(Object o) {
     if (o == null || getClass() != o.getClass()) {
       return false;
     }
-    User user = (User) o;
+    var user = (User) o;
     return isActive == user.isActive && Objects.equals(firstName, user.firstName) && Objects
         .equals(lastName, user.lastName) && Objects.equals(userId, user.userId);
   }

converter/src/main/java/com/iluwatar/converter/UserConverter.java

@@ -28,13 +28,16 @@
  */
 public class UserConverter extends Converter<UserDto, User> {
 
-  /**
-   * Constructor.
-   */
   public UserConverter() {
-    super(userDto -> new User(userDto.getFirstName(), userDto.getLastName(), userDto.isActive(),
-            userDto.getEmail()),
-        user -> new UserDto(user.getFirstName(), user.getLastName(), user.isActive(),
-            user.getUserId()));
+    super(UserConverter::convertToEntity, UserConverter::convertToDto);
   }
+
+  private static UserDto convertToDto(User user) {
+    return new UserDto(user.getFirstName(), user.getLastName(), user.isActive(), user.getUserId());
+  }
+
+  private static User convertToEntity(UserDto dto) {
+    return new User(dto.getFirstName(), dto.getLastName(), dto.isActive(), dto.getEmail());
+  }
+
 }

converter/src/main/java/com/iluwatar/converter/UserDto.java

@@ -74,7 +74,7 @@ public boolean equals(Object o) {
     if (o == null || getClass() != o.getClass()) {
       return false;
     }
-    UserDto userDto = (UserDto) o;
+    var userDto = (UserDto) o;
     return isActive == userDto.isActive && Objects.equals(firstName, userDto.firstName) && Objects
         .equals(lastName, userDto.lastName) && Objects.equals(email, userDto.email);
   }