Fix flaky test in SpringSecurityPasswordValidationCallbackHandlerTest and SpringDigestPasswordValidationCallbackHandlerTest

Author: KellyShao

spring-ws-security/src/test/java/org/springframework/ws/soap/security/wss4j2/callback/SpringSecurityPasswordValidationCallbackHandlerTest.java

@@ -51,7 +51,9 @@ public class SpringSecurityPasswordValidationCallbackHandlerTest {
 
 	@BeforeEach
 	public void setUp() {
-
+		// add clearContext() at the beginning of each method in case {@code SecurityContextHolder} isn't clean
+		SecurityContextHolder.clearContext();
+		
 		callbackHandler = new SpringSecurityPasswordValidationCallbackHandler();
 
 		grantedAuthority = new SimpleGrantedAuthority("ROLE_1");

spring-ws-security/src/test/java/org/springframework/ws/soap/security/xwss/callback/SpringDigestPasswordValidationCallbackHandlerTest.java

@@ -46,9 +46,11 @@ public class SpringDigestPasswordValidationCallbackHandlerTest {
 	private String password;
 
 	private PasswordValidationCallback callback;
-
+	
 	@BeforeEach
 	public void setUp() {
+		// add clearContext() at the beginning of each method in case {@code SecurityContextHolder} isn't clean
+		SecurityContextHolder.clearContext();
 
 		callbackHandler = new SpringDigestPasswordValidationCallbackHandler();
 		userDetailsService = createMock(UserDetailsService.class);