Collection.isEmpty() should be used to test for emptiness

Closes gh-1670

spring-context/src/main/java/org/springframework/cache/config/CacheAdviceParser.java

@@ -72,7 +72,7 @@ class CacheAdviceParser extends AbstractSingleBeanDefinitionParser {
 		CacheNamespaceHandler.parseKeyGenerator(element, builder.getBeanDefinition());
 
 		List<Element> cacheDefs = DomUtils.getChildElementsByTagName(element, DEFS_ELEMENT);
-		if (cacheDefs.size() >= 1) {
+		if (!cacheDefs.isEmpty()) {
 			// Using attributes source.
 			List<RootBeanDefinition> attributeSourceDefinitions = parseDefinitionsSources(cacheDefs, parserContext);
 			builder.addPropertyValue("cacheOperationSources", attributeSourceDefinitions);

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

@@ -95,7 +95,7 @@ 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.size() > 0) {
+			if (servers != null && !servers.isEmpty()) {
 				// 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

@@ -568,7 +568,7 @@ public class DataBinder implements PropertyEditorRegistry, TypeConverter {
 	 */
 	@Nullable
 	public Validator getValidator() {
-		return (this.validators.size() > 0 ? this.validators.get(0) : null);
+		return (!this.validators.isEmpty() ? this.validators.get(0) : null);
 	}
 
 	/**