Replace RestTemplate by RestClient

src/main/java/org/fairdatateam/fairdatapoint/config/HttpClientConfig.java

@@ -22,32 +22,30 @@
  */
 package org.fairdatateam.fairdatapoint.config;
 
-import org.springframework.boot.restclient.RestTemplateBuilder;
+import org.springframework.boot.http.client.HttpClientSettings;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.web.client.RestClient;
-import org.springframework.web.client.RestTemplate;
 
 import java.time.Duration;
 
 @Configuration
 public class HttpClientConfig {
-    // TODO: use newer WebClient (Spring 5)
 
     private static final Duration TIMEOUT = Duration.ofSeconds(5);
 
-    @Bean RestClient restClient(RestClient.Builder builder) {
+    @Bean
+    public RestClient restClient(RestClient.Builder builder) {
         // The builder argument is required for autoconfiguration of MockRestServiceServer in tests
         // https://docs.spring.io/spring-framework/reference/integration/rest-clients.html
         return builder.build();
     }
 
     @Bean
-    public RestTemplate restTemplate(RestTemplateBuilder restTemplateBuilder) {
-        return restTemplateBuilder
-                .connectTimeout(TIMEOUT)
-                .readTimeout(TIMEOUT)
-                .build();
+    public HttpClientSettings httpClientSettings() {
+        return HttpClientSettings.defaults()
+                .withConnectTimeout(TIMEOUT)
+                .withReadTimeout(TIMEOUT);
     }
 
 }

src/main/java/org/fairdatateam/fairdatapoint/service/index/harvester/HarvesterService.java

@@ -32,13 +32,12 @@
 import org.eclipse.rdf4j.model.vocabulary.LDP;
 import org.eclipse.rdf4j.model.vocabulary.RDF;
 import org.eclipse.rdf4j.rio.RDFFormat;
-import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.*;
 import org.springframework.scheduling.annotation.Async;
 import org.springframework.stereotype.Service;
 import org.springframework.web.client.HttpClientErrorException;
+import org.springframework.web.client.RestClient;
 import org.springframework.web.client.RestClientException;
-import org.springframework.web.client.RestTemplate;
 
 import java.util.*;
 
@@ -55,13 +54,21 @@
 @Service
 public class HarvesterService {
 
+    private static final MediaType TURTLE = MediaType.parseMediaType(RDFFormat.TURTLE.getDefaultMIMEType());
+
     private static final String DEFAULT_NAVIGATION_SHACL = "defaultNavigationShacl.ttl";
 
-    @Autowired
-    private GenericMetadataRepository genericMetadataRepository;
+    private final GenericMetadataRepository genericMetadataRepository;
+
+    private final RestClient client;
 
-    @Autowired
-    private RestTemplate restTemplate;
+    /**
+     * Constructor (autowired)
+     */
+    public HarvesterService(GenericMetadataRepository genericMetadataRepository, RestClient client) {
+        this.genericMetadataRepository = genericMetadataRepository;
+        this.client = client;
+    }
 
     public void deleteHarvestedData(String clientUrl) throws MetadataRepositoryException {
         genericMetadataRepository.remove(i(clientUrl));
@@ -137,12 +144,12 @@ model, i(container.stringValue()), LDP.CONTAINS
 
     private Model makeRequest(String uri) {
         log.info("Making request to '{}'", uri);
-        final HttpHeaders headers = new HttpHeaders();
-        headers.setAccept(List.of(MediaType.parseMediaType(RDFFormat.TURTLE.getDefaultMIMEType())));
-        final HttpEntity<Void> entity = new HttpEntity<>(null, headers);
         try {
-            final ResponseEntity<String> response =
-                    restTemplate.exchange(uri, HttpMethod.GET, entity, String.class);
+            final ResponseEntity<String> response = client.method(HttpMethod.GET)
+                    .uri(uri)
+                    .headers(httpHeaders -> httpHeaders.setAccept(List.of(TURTLE)))
+                    .retrieve()
+                    .toEntity(String.class);
             if (!response.getStatusCode().is2xxSuccessful()) {
                 log.info("Request to '{}' failed ({})", uri, response.getStatusCode());
                 throw new HttpClientErrorException(response.getStatusCode());

src/main/java/org/fairdatateam/fairdatapoint/service/ping/PingService.java

@@ -27,12 +27,11 @@
 import org.fairdatateam.fairdatapoint.config.properties.PingProperties;
 import org.fairdatateam.fairdatapoint.entity.settings.Settings;
 import org.fairdatateam.fairdatapoint.service.settings.SettingsService;
-import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.scheduling.annotation.Async;
 import org.springframework.scheduling.annotation.Scheduled;
 import org.springframework.stereotype.Service;
-import org.springframework.web.client.RestTemplate;
+import org.springframework.web.client.RestClient;
 
 import java.util.List;
 import java.util.Map;
@@ -43,17 +42,23 @@
 @ConditionalOnProperty(name = "ping.enabled", havingValue = "true", matchIfMissing = true)
 public class PingService {
 
-    @Autowired
-    private PingProperties pingProperties;
+    private final PingProperties pingProperties;
 
-    @Autowired
-    private InstanceProperties instanceProperties;
+    private final InstanceProperties instanceProperties;
 
-    @Autowired
-    private SettingsService settingsService;
+    private final SettingsService settingsService;
 
-    @Autowired
-    private RestTemplate client;
+    private final RestClient client;
+
+    /**
+     * Constructor (autowired)
+     */
+    public PingService(PingProperties pingProperties, InstanceProperties instanceProperties, SettingsService settingsService, RestClient client) {
+        this.pingProperties = pingProperties;
+        this.instanceProperties = instanceProperties;
+        this.settingsService = settingsService;
+        this.client = client;
+    }
 
     @Scheduled(
             initialDelayString = "${ping.initDelay:#{10*1000}}",
@@ -80,7 +85,7 @@ public void ping() {
     void pingEndpoint(String endpoint, Map<String, String> request) {
         try {
             log.info("Pinging {}", endpoint);
-            client.postForEntity(endpoint, request, String.class);
+            client.post().uri(endpoint).body(request).retrieve().toEntity(String.class);
         }
         catch (Exception exception) {
             log.warn("Failed to ping {}: {}", endpoint, exception.getMessage());