Repackage output capture and always use extension declaratively

Closes gh-17029

spring-boot-samples/spring-boot-sample-webservices/src/test/java/sample/webservices/SampleWsApplicationTests.java

@@ -23,23 +23,21 @@ import javax.xml.transform.stream.StreamSource;
 
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.extension.RegisterExtension;
+import org.junit.jupiter.api.extension.ExtendWith;
 
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
-import org.springframework.boot.test.extension.CapturedOutput;
-import org.springframework.boot.test.extension.OutputExtension;
+import org.springframework.boot.test.system.CapturedOutput;
+import org.springframework.boot.test.system.OutputCaptureExtension;
 import org.springframework.boot.web.server.LocalServerPort;
 import org.springframework.ws.client.core.WebServiceTemplate;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
 @SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
+@ExtendWith(OutputCaptureExtension.class)
 class SampleWsApplicationTests {
 
-	@RegisterExtension
-	CapturedOutput output = OutputExtension.capture();
-
 	private WebServiceTemplate webServiceTemplate = new WebServiceTemplate();
 
 	@LocalServerPort
@@ -52,7 +50,7 @@ class SampleWsApplicationTests {
 	}
 
 	@Test
-	void testSendingHolidayRequest() {
+	void testSendingHolidayRequest(CapturedOutput capturedOutput) {
 		final String request = "<hr:HolidayRequest xmlns:hr=\"https://company.example.com/hr/schemas\">"
 				+ "   <hr:Holiday>" + "      <hr:StartDate>2013-10-20</hr:StartDate>"
 				+ "      <hr:EndDate>2013-11-22</hr:EndDate>" + "   </hr:Holiday>"
@@ -63,7 +61,7 @@ class SampleWsApplicationTests {
 		StreamSource source = new StreamSource(new StringReader(request));
 		StreamResult result = new StreamResult(System.out);
 		this.webServiceTemplate.sendSourceAndReceiveToResult(source, result);
-		assertThat(this.output.toString()).contains("Booking holiday for");
+		assertThat(capturedOutput).contains("Booking holiday for");
 	}
 
 }