Add JSON content type when registering to Admin Server

spring-boot-admin-starter-client/src/main/java/de/codecentric/boot/admin/services/SpringBootAdminRegistrator.java

@@ -15,9 +15,14 @@
  */
 package de.codecentric.boot.admin.services;
 
+import java.util.Collections;
+
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.client.RestTemplate;
 
@@ -32,6 +37,14 @@ public class SpringBootAdminRegistrator {
 
 	private static final Logger LOGGER = LoggerFactory.getLogger(SpringBootAdminRegistrator.class);
 
+	private static HttpHeaders HTTP_HEADERS = createHttpHeaders();
+
+	private AdminClientProperties clientProps;
+
+	private AdminProperties adminProps;
+
+	private final RestTemplate template;
+
 	public SpringBootAdminRegistrator(RestTemplate template, AdminProperties adminProps,
 			AdminClientProperties clientProps) {
 		this.clientProps = clientProps;
@@ -39,11 +52,12 @@ public class SpringBootAdminRegistrator {
 		this.template = template;
 	}
 
-	private AdminClientProperties clientProps;
-
-	private AdminProperties adminProps;
-
-	private final RestTemplate template;
+	private static HttpHeaders createHttpHeaders() {
+		HttpHeaders headers = new HttpHeaders();
+		headers.setContentType(MediaType.APPLICATION_JSON);
+		headers.setAccept(Collections.singletonList(MediaType.APPLICATION_JSON));
+		return HttpHeaders.readOnlyHttpHeaders(headers);
+	}
 
 	/**
 	 * Registers the client application at spring-boot-admin-server.
@@ -54,7 +68,8 @@ public class SpringBootAdminRegistrator {
 		String adminUrl = adminProps.getUrl() + '/' + adminProps.getContextPath();
 
 		try {
-			ResponseEntity<Application> response = template.postForEntity(adminUrl, app, Application.class);
+			ResponseEntity<Application> response = template.postForEntity(adminUrl,
+					new HttpEntity<Application>(app, HTTP_HEADERS), Application.class);
 
 			if (response.getStatusCode().equals(HttpStatus.CREATED)) {
 				LOGGER.debug("Application registered itself as {}", response.getBody());

spring-boot-admin-starter-client/src/test/java/de/codecentric/boot/admin/services/SpringBootAdminRegistratorTest.java

@@ -23,8 +23,13 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
+import java.util.Collections;
+
 import org.junit.Test;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.client.RestClientException;
 import org.springframework.web.client.RestTemplate;
@@ -45,15 +50,23 @@ public class SpringBootAdminRegistratorTest {
 		clientProps.setName("AppName");
 
 		RestTemplate restTemplate = mock(RestTemplate.class);
-		when(restTemplate.postForEntity(isA(String.class), isA(Application.class), eq(Application.class))).thenReturn(
+		when(
+				restTemplate.postForEntity(isA(String.class), isA(HttpEntity.class),
+						eq(Application.class))).thenReturn(
 								new ResponseEntity<Application>(HttpStatus.CREATED));
 
 		SpringBootAdminRegistrator registrator = new SpringBootAdminRegistrator(restTemplate, adminProps, clientProps);
 		boolean result = registrator.register();
 
+		HttpHeaders headers = new HttpHeaders();
+		headers.setContentType(MediaType.APPLICATION_JSON);
+		headers.setAccept(Collections.singletonList(MediaType.APPLICATION_JSON));
+
 		assertTrue(result);
 		verify(restTemplate).postForEntity("http://sba:8080/api/applications",
-				new Application("http://localhost:8080", "AppName"), Application.class);
+				new HttpEntity<Application>(new Application("http://localhost:8080",
+						"AppName"),
+						headers), Application.class);
 	}
 
 	@Test