spring-rest-shell (#2928)

* code snippets for the `Java 9 Stream API improvements` article

* code snippets for the `Java 9 Stream API improvements` article [2 attempt]

* removed the first attempt

* the Spring 5 WebClient

* delted stream features test

* HttpMediaTypeNotAcceptableExceptionExampleController [0]

* reactive web client service was removed

* new WebClient

* new WebClient [2]

* spring-rest-shell init

* pom added

* readme added

spring-rest-shell/src/main/java/com/baeldung/acticle/Article.java

@@ -0,0 +1,40 @@
+package com.baeldung.acticle;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+
+@Entity
+public final class Article {
+
+    @Id
+    @GeneratedValue
+    private Long id;
+    private String title;
+    private String content;
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public String getContent() {
+        return content;
+    }
+
+    public void setContent(String content) {
+        this.content = content;
+    }
+
+}

spring-rest-shell/src/main/java/com/baeldung/acticle/ArticleRepository.java

@@ -0,0 +1,18 @@
+package com.baeldung.acticle;
+
+import org.springframework.data.repository.CrudRepository;
+import org.springframework.data.repository.query.Param;
+import org.springframework.data.rest.core.annotation.RepositoryRestResource;
+
+import java.util.Optional;
+
+@RepositoryRestResource(
+        path = "articles",
+        collectionResourceRel = "articles",
+        itemResourceRel = "article"
+)
+public interface ArticleRepository extends CrudRepository<Article, Long> {
+
+    Optional<Article> findByTitle(@Param("title") String title);
+
+}