Polishing

spring-context/src/main/java/org/springframework/jmx/support/JmxUtils.java

@@ -35,6 +35,7 @@ import org.apache.commons.logging.LogFactory;
 import org.springframework.jmx.MBeanServerNotFoundException;
 import org.springframework.lang.Nullable;
 import org.springframework.util.ClassUtils;
+import org.springframework.util.CollectionUtils;
 import org.springframework.util.ObjectUtils;
 import org.springframework.util.StringUtils;
 
@@ -69,8 +70,7 @@ public abstract class JmxUtils {
 	 * {@code MBeanServer} can be found. Logs a warning if more than one
 	 * {@code MBeanServer} found, returning the first one from the list.
 	 * @return the {@code MBeanServer} if found
-	 * @throws org.springframework.jmx.MBeanServerNotFoundException
-	 * if no {@code MBeanServer} could be found
+	 * @throws MBeanServerNotFoundException if no {@code MBeanServer} could be found
 	 * @see javax.management.MBeanServerFactory#findMBeanServer
 	 */
 	public static MBeanServer locateMBeanServer() throws MBeanServerNotFoundException {
@@ -85,8 +85,7 @@ public abstract class JmxUtils {
 	 * If this parameter is {@code null}, all registered MBeanServers are considered.
 	 * If the empty String is given, the platform MBeanServer will be returned.
 	 * @return the {@code MBeanServer} if found
-	 * @throws org.springframework.jmx.MBeanServerNotFoundException
-	 * if no {@code MBeanServer} could be found
+	 * @throws MBeanServerNotFoundException if no {@code MBeanServer} could be found
 	 * @see javax.management.MBeanServerFactory#findMBeanServer(String)
 	 */
 	public static MBeanServer locateMBeanServer(@Nullable String agentId) throws MBeanServerNotFoundException {
@@ -95,7 +94,7 @@ public abstract class JmxUtils {
 		// null means any registered server, but "" specifically means the platform server
 		if (!"".equals(agentId)) {
 			List<MBeanServer> servers = MBeanServerFactory.findMBeanServer(agentId);
-			if (servers != null && !servers.isEmpty()) {
+			if (!CollectionUtils.isEmpty(servers)) {
 				// Check to see if an MBeanServer is registered.
 				if (servers.size() > 1 && logger.isWarnEnabled()) {
 					logger.warn("Found more than one MBeanServer instance" +

spring-context/src/main/java/org/springframework/validation/DataBinder.java

@@ -535,9 +535,10 @@ public class DataBinder implements PropertyEditorRegistry, TypeConverter {
 	}
 
 	private void assertValidators(Validator... validators) {
+		Object target = getTarget();
 		for (Validator validator : validators) {
-			if (validator != null && (getTarget() != null && !validator.supports(getTarget().getClass()))) {
-				throw new IllegalStateException("Invalid target for Validator [" + validator + "]: " + getTarget());
+			if (validator != null && (target != null && !validator.supports(target.getClass()))) {
+				throw new IllegalStateException("Invalid target for Validator [" + validator + "]: " + target);
 			}
 		}
 	}

spring-websocket/src/main/java/org/springframework/web/socket/sockjs/client/UndertowXhrTransport.java

@@ -54,6 +54,7 @@ import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.StringUtils;
 import org.springframework.util.concurrent.SettableListenableFuture;
 import org.springframework.web.client.HttpServerErrorException;
 import org.springframework.web.socket.CloseStatus;
@@ -276,7 +277,7 @@ public class UndertowXhrTransport extends AbstractXhrTransport {
 			try {
 				ClientRequest request = new ClientRequest().setMethod(method).setPath(url.getPath());
 				request.getRequestHeaders().add(HttpString.tryFromString(HttpHeaders.HOST), url.getHost());
-				if (body != null && !body.isEmpty()) {
+				if (StringUtils.hasLength(body)) {
 					HttpString headerName = HttpString.tryFromString(HttpHeaders.CONTENT_LENGTH);
 					request.getRequestHeaders().add(headerName, body.length());
 				}