Added examples for the @RestClientTest article, fixed mail port (#513)

spring-boot/src/main/java/org/baeldung/client/Details.java

@@ -0,0 +1,32 @@
+package org.baeldung.client;
+
+public class Details {
+
+    private String name;
+
+    private String login;
+
+    public Details() {
+    }
+
+    public Details(String name, String login) {
+        this.name = name;
+        this.login = login;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getLogin() {
+        return login;
+    }
+
+    public void setLogin(String login) {
+        this.login = login;
+    }
+}

spring-boot/src/main/java/org/baeldung/client/DetailsServiceClient.java

@@ -0,0 +1,20 @@
+package org.baeldung.client;
+
+import org.springframework.boot.web.client.RestTemplateBuilder;
+import org.springframework.stereotype.Service;
+import org.springframework.web.client.RestTemplate;
+
+@Service
+public class DetailsServiceClient {
+
+    private final RestTemplate restTemplate;
+
+    public DetailsServiceClient(RestTemplateBuilder restTemplateBuilder) {
+        restTemplate = restTemplateBuilder.build();
+    }
+
+    public Details getUserDetails(String name) {
+        return restTemplate.getForObject("/{name}/details", Details.class, name);
+    }
+
+}