Merge branch '4.1.x'

Closes gh-51122

Author: snicoll

buildSrc/src/main/java/org/springframework/boot/build/bom/CheckLinks.java

@@ -28,11 +28,10 @@
 import org.gradle.api.tasks.TaskAction;
 import org.gradle.internal.impldep.org.apache.http.client.config.CookieSpecs;
 
-import org.springframework.http.HttpMethod;
 import org.springframework.http.ResponseEntity;
 import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
-import org.springframework.web.client.NoOpResponseErrorHandler;
-import org.springframework.web.client.RestTemplate;
+import org.springframework.web.client.RestClient;
+import org.springframework.web.client.RestClient.ResponseSpec.ErrorHandler;
 
 /**
  * Task to check that links are working.
@@ -42,6 +41,9 @@
  */
 public abstract class CheckLinks extends DefaultTask {
 
+	private static final ErrorHandler NOOP_ERROR_HANDLER = (request, response) -> {
+	};
+
 	private final BomExtension bom;
 
 	@Inject
@@ -54,14 +56,16 @@ void releaseNotes() {
 		RequestConfig config = RequestConfig.custom().setCookieSpec(CookieSpecs.IGNORE_COOKIES).build();
 		CloseableHttpClient httpClient = HttpClients.custom().setDefaultRequestConfig(config).build();
 		HttpComponentsClientHttpRequestFactory requestFactory = new HttpComponentsClientHttpRequestFactory(httpClient);
-		RestTemplate restTemplate = new RestTemplate(requestFactory);
-		restTemplate.setErrorHandler(new NoOpResponseErrorHandler());
+		RestClient restClient = RestClient.builder()
+			.requestFactory(requestFactory)
+			.defaultStatusHandler((status) -> true, NOOP_ERROR_HANDLER)
+			.build();
 		for (Library library : this.bom.getLibraries()) {
 			library.getLinks().forEach((name, links) -> links.forEach((link) -> {
 				URI uri;
 				try {
 					uri = new URI(link.url(library));
-					ResponseEntity<String> response = restTemplate.exchange(uri, HttpMethod.HEAD, null, String.class);
+					ResponseEntity<String> response = restClient.head().uri(uri).retrieve().toEntity(String.class);
 					System.out.printf("[%3d] %s - %s (%s)%n", response.getStatusCode().value(), library.getName(), name,
 							uri);
 				}

buildSrc/src/main/java/org/springframework/boot/build/bom/bomr/MavenMetadataVersionResolver.java

@@ -18,7 +18,6 @@
 
 import java.net.URI;
 import java.util.Collection;
-import java.util.Collections;
 import java.util.HashSet;
 import java.util.Set;
 import java.util.SortedSet;
@@ -37,13 +36,10 @@
 
 import org.springframework.boot.build.bom.bomr.version.DependencyVersion;
 import org.springframework.boot.build.xml.XmlDocument;
-import org.springframework.http.HttpEntity;
-import org.springframework.http.HttpHeaders;
-import org.springframework.http.HttpMethod;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.converter.StringHttpMessageConverter;
 import org.springframework.web.client.HttpClientErrorException;
-import org.springframework.web.client.RestTemplate;
+import org.springframework.web.client.RestClient;
 import org.springframework.web.util.UriComponentsBuilder;
 
 /**
@@ -54,16 +50,19 @@
  */
 final class MavenMetadataVersionResolver implements VersionResolver {
 
-	private final RestTemplate rest;
+	private final RestClient rest;
 
 	private final Collection<MavenArtifactRepository> repositories;
 
 	MavenMetadataVersionResolver(Collection<MavenArtifactRepository> repositories) {
-		this(new RestTemplate(Collections.singletonList(new StringHttpMessageConverter())), repositories);
+		this(RestClient.builder()
+			.configureMessageConverters(
+					(converters) -> converters.disableDefaults().withStringConverter(new StringHttpMessageConverter()))
+			.build(), repositories);
 	}
 
-	MavenMetadataVersionResolver(RestTemplate restTemplate, Collection<MavenArtifactRepository> repositories) {
-		this.rest = restTemplate;
+	MavenMetadataVersionResolver(RestClient restClient, Collection<MavenArtifactRepository> repositories) {
+		this.rest = restClient;
 		this.repositories = repositories;
 	}
 
@@ -83,14 +82,13 @@ private Set<String> resolveVersions(String groupId, String artifactId, MavenArti
 			.build()
 			.toUri();
 		try {
-			HttpHeaders headers = new HttpHeaders();
-			PasswordCredentials credentials = credentialsOf(repository);
-			String username = (credentials != null) ? credentials.getUsername() : null;
-			if (username != null) {
-				headers.setBasicAuth(username, credentials.getPassword());
-			}
-			HttpEntity<Void> request = new HttpEntity<>(headers);
-			String metadata = this.rest.exchange(url, HttpMethod.GET, request, String.class).getBody();
+			String metadata = this.rest.get().uri(url).headers((headers) -> {
+				PasswordCredentials credentials = credentialsOf(repository);
+				String username = (credentials != null) ? credentials.getUsername() : null;
+				if (username != null) {
+					headers.setBasicAuth(username, credentials.getPassword());
+				}
+			}).retrieve().body(String.class);
 			Document metadataDocument = XmlDocument.parseContent(metadata);
 			NodeList versionNodes = (NodeList) XPathFactory.newInstance()
 				.newXPath()

buildSrc/src/main/java/org/springframework/boot/build/bom/bomr/ReleaseSchedule.java

@@ -28,8 +28,7 @@
 import org.springframework.boot.build.bom.bomr.version.DependencyVersion;
 import org.springframework.http.ResponseEntity;
 import org.springframework.util.LinkedCaseInsensitiveMap;
-import org.springframework.web.client.RestOperations;
-import org.springframework.web.client.RestTemplate;
+import org.springframework.web.client.RestClient;
 
 /**
  * Release schedule for Spring projects, retrieved from
@@ -41,20 +40,22 @@ class ReleaseSchedule {
 
 	private static final Pattern LIBRARY_AND_VERSION = Pattern.compile("([A-Za-z0-9 ]+) ([0-9A-Za-z.-]+)");
 
-	private final RestOperations rest;
+	private final RestClient rest;
 
 	ReleaseSchedule() {
-		this(new RestTemplate());
+		this(RestClient.create());
 	}
 
-	ReleaseSchedule(RestOperations rest) {
+	ReleaseSchedule(RestClient rest) {
 		this.rest = rest;
 	}
 
 	@SuppressWarnings({ "unchecked", "rawtypes" })
 	Map<String, List<Release>> releasesBetween(OffsetDateTime start, OffsetDateTime end) {
-		ResponseEntity<List> response = this.rest
-			.getForEntity("https://calendar.spring.io/releases?start=" + start + "&end=" + end, List.class);
+		ResponseEntity<List> response = this.rest.get()
+			.uri("https://calendar.spring.io/releases?start=" + start + "&end=" + end)
+			.retrieve()
+			.toEntity(List.class);
 		List<Map<String, String>> body = response.getBody();
 		Map<String, List<Release>> releasesByLibrary = new LinkedCaseInsensitiveMap<>();
 		body.stream()

buildSrc/src/main/java/org/springframework/boot/build/bom/bomr/github/Issue.java

@@ -20,7 +20,7 @@
 import java.util.List;
 import java.util.Map;
 
-import org.springframework.web.client.RestTemplate;
+import org.springframework.web.client.RestClient;
 
 /**
  * Minimal representation of a GitHub issue.
@@ -29,15 +29,15 @@
  */
 public class Issue {
 
-	private final RestTemplate rest;
+	private final RestClient rest;
 
 	private final int number;
 
 	private final String title;
 
 	private final State state;
 
-	Issue(RestTemplate rest, int number, String title, State state) {
+	Issue(RestClient rest, int number, String title, State state) {
 		this.rest = rest;
 		this.number = number;
 		this.title = title;
@@ -62,7 +62,7 @@ public State getState() {
 	 */
 	public void label(List<String> labels) {
 		Map<String, List<String>> body = Collections.singletonMap("labels", labels);
-		this.rest.put("issues/" + this.number + "/labels", body);
+		this.rest.put().uri("issues/" + this.number + "/labels").body(body).retrieve().toBodilessEntity();
 	}
 
 	public enum State {

buildSrc/src/main/java/org/springframework/boot/build/bom/bomr/github/StandardGitHub.java

@@ -17,13 +17,10 @@
 package org.springframework.boot.build.bom.bomr.github;
 
 import java.util.Base64;
-import java.util.Collections;
 
 import org.springframework.http.MediaType;
 import org.springframework.http.converter.json.JacksonJsonHttpMessageConverter;
-import org.springframework.web.client.RestTemplate;
-import org.springframework.web.util.DefaultUriBuilderFactory;
-import org.springframework.web.util.UriTemplateHandler;
+import org.springframework.web.client.RestClient;
 
 /**
  * Standard implementation of {@link GitHub}.
@@ -43,24 +40,24 @@ final class StandardGitHub implements GitHub {
 
 	@Override
 	public GitHubRepository getRepository(String organization, String name) {
-		RestTemplate restTemplate = createRestTemplate();
-		restTemplate.getInterceptors().add((request, body, execution) -> {
-			request.getHeaders().add("User-Agent", StandardGitHub.this.username);
-			request.getHeaders()
-				.add("Authorization", "Basic " + Base64.getEncoder()
-					.encodeToString((StandardGitHub.this.username + ":" + StandardGitHub.this.password).getBytes()));
-			request.getHeaders().add("Accept", MediaType.APPLICATION_JSON_VALUE);
-			return execution.execute(request, body);
-		});
-		UriTemplateHandler uriTemplateHandler = new DefaultUriBuilderFactory(
-				"https://api.github.com/repos/" + organization + "/" + name + "/");
-		restTemplate.setUriTemplateHandler(uriTemplateHandler);
-		return new StandardGitHubRepository(restTemplate);
+		return new StandardGitHubRepository(createRestClient(organization, name));
 	}
 
-	@SuppressWarnings({ "deprecation", "removal" })
-	private RestTemplate createRestTemplate() {
-		return new RestTemplate(Collections.singletonList(new JacksonJsonHttpMessageConverter()));
+	private RestClient createRestClient(String organization, String name) {
+		return RestClient.builder()
+			.baseUrl("https://api.github.com/repos/" + organization + "/" + name + "/")
+			.configureMessageConverters((converters) -> converters.disableDefaults()
+				.withJsonConverter(new JacksonJsonHttpMessageConverter()))
+			.requestInterceptor((request, body, execution) -> {
+				request.getHeaders().add("User-Agent", StandardGitHub.this.username);
+				request.getHeaders()
+					.add("Authorization", "Basic " + Base64.getEncoder()
+						.encodeToString(
+								(StandardGitHub.this.username + ":" + StandardGitHub.this.password).getBytes()));
+				request.getHeaders().add("Accept", MediaType.APPLICATION_JSON_VALUE);
+				return execution.execute(request, body);
+			})
+			.build();
 	}
 
 }

buildSrc/src/main/java/org/springframework/boot/build/bom/bomr/github/StandardGitHubRepository.java

@@ -27,8 +27,8 @@
 
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.client.HttpClientErrorException.Forbidden;
+import org.springframework.web.client.RestClient;
 import org.springframework.web.client.RestClientException;
-import org.springframework.web.client.RestTemplate;
 
 /**
  * Standard implementation of {@link GitHubRepository}.
@@ -37,10 +37,10 @@
  */
 final class StandardGitHubRepository implements GitHubRepository {
 
-	private final RestTemplate rest;
+	private final RestClient rest;
 
-	StandardGitHubRepository(RestTemplate restTemplate) {
-		this.rest = restTemplate;
+	StandardGitHubRepository(RestClient restClient) {
+		this.rest = restClient;
 	}
 
 	@Override
@@ -56,7 +56,11 @@ public int openIssue(String title, String body, List<String> labels, Milestone m
 		}
 		requestBody.put("body", body);
 		try {
-			ResponseEntity<Map> response = this.rest.postForEntity("issues", requestBody, Map.class);
+			ResponseEntity<Map> response = this.rest.post()
+				.uri("issues")
+				.body(requestBody)
+				.retrieve()
+				.toEntity(Map.class);
 			// See gh-30304
 			sleep(Duration.ofSeconds(3));
 			return (Integer) response.getBody().get("number");
@@ -92,7 +96,7 @@ public List<Issue> findIssues(List<String> labels, Milestone milestone) {
 
 	@SuppressWarnings({ "rawtypes", "unchecked" })
 	private <T> List<T> get(String name, Function<Map<String, Object>, T> mapper) {
-		ResponseEntity<List> response = this.rest.getForEntity(name, List.class);
+		ResponseEntity<List> response = this.rest.get().uri(name).retrieve().toEntity(List.class);
 		return ((List<Map<String, Object>>) response.getBody()).stream().map(mapper).toList();
 	}
 

buildSrc/src/test/java/org/springframework/boot/build/bom/bomr/ReleaseScheduleTests.java

@@ -26,7 +26,7 @@
 import org.springframework.core.io.ClassPathResource;
 import org.springframework.http.MediaType;
 import org.springframework.test.web.client.MockRestServiceServer;
-import org.springframework.web.client.RestTemplate;
+import org.springframework.web.client.RestClient;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.springframework.test.web.client.match.MockRestRequestMatchers.requestTo;
@@ -39,11 +39,11 @@
  */
 class ReleaseScheduleTests {
 
-	private final RestTemplate rest = new RestTemplate();
+	private final RestClient.Builder restBuilder = RestClient.builder();
 
-	private final ReleaseSchedule releaseSchedule = new ReleaseSchedule(this.rest);
+	private final MockRestServiceServer server = MockRestServiceServer.bindTo(this.restBuilder).build();
 
-	private final MockRestServiceServer server = MockRestServiceServer.bindTo(this.rest).build();
+	private final ReleaseSchedule releaseSchedule = new ReleaseSchedule(this.restBuilder.build());
 
 	@Test
 	void releasesBetween() {

integration-test/spring-boot-integration-tests/src/test/java/org/springframework/boot/web/servlet/support/ErrorPageFilterIntegrationTests.java

@@ -45,7 +45,7 @@
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.ResponseBody;
 import org.springframework.web.bind.annotation.ResponseStatus;
-import org.springframework.web.client.RestTemplate;
+import org.springframework.web.client.RestClient;
 import org.springframework.web.servlet.DispatcherServlet;
 import org.springframework.web.servlet.HandlerInterceptor;
 import org.springframework.web.servlet.ModelAndView;
@@ -93,9 +93,11 @@ void ok() throws Exception {
 	private void doTest(AnnotationConfigServletWebServerApplicationContext context, String resourcePath,
 			HttpStatus status) throws Exception {
 		int port = context.getWebServer().getPort();
-		RestTemplate template = new RestTemplate();
-		ResponseEntity<String> entity = template.getForEntity(new URI("http://localhost:" + port + resourcePath),
-				String.class);
+		RestClient restClient = RestClient.create();
+		ResponseEntity<String> entity = restClient.get()
+			.uri(new URI("http://localhost:" + port + resourcePath))
+			.retrieve()
+			.toEntity(String.class);
 		assertThat(entity.getBody()).isEqualTo("Hello World");
 		assertThat(entity.getStatusCode()).isEqualTo(status);
 	}