Polish CronSequenceGenerator and tests

spring-context/src/main/java/org/springframework/scheduling/support/CronSequenceGenerator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -95,7 +95,6 @@ public class CronSequenceGenerator {
 		parse(expression);
 	}
 
-
 	/**
 	 * Return the cron pattern that this sequence generator has been built for.
 	 */
@@ -149,22 +148,6 @@ public class CronSequenceGenerator {
 		return calendar.getTime();
 	}
 
-	/**
-	 * Indicates whether the specified cron expression can be parsed into a
-	 * valid cron sequence generator
-	 * @param cronExpression the expression to evaluate
-	 * @return a boolean indicating whether the given expression is a valid cron
-	 *         expression
-	 */
-	public static boolean isValidExpression(String cronExpression) {
-		String[] fields = StringUtils.tokenizeToStringArray(cronExpression, " ");
-		return validateCronFields(fields);
-	}
-
-	private static boolean validateCronFields(String[] fields) {
-		return fields != null && fields.length == 6;
-	}
-
 	private void doNext(Calendar calendar, int dot) {
 		List<Integer> resets = new ArrayList<Integer>();
 
@@ -278,7 +261,7 @@ public class CronSequenceGenerator {
 	 */
 	private void parse(String expression) throws IllegalArgumentException {
 		String[] fields = StringUtils.tokenizeToStringArray(expression, " ");
-		if (!validateCronFields(fields)) {
+		if (!areValidCronFields(fields)) {
 			throw new IllegalArgumentException(String.format(
 					"Cron expression must consist of 6 fields (found %d in \"%s\")", fields.length, expression));
 		}
@@ -399,6 +382,23 @@ public class CronSequenceGenerator {
 	}
 
 
+	/**
+	 * Determine whether the specified expression represents a valid cron pattern.
+	 * <p>Specifically, this method verifies that the expression contains six
+	 * fields separated by single spaces.
+	 * @param expression the expression to evaluate
+	 * @return {@code true} if the given expression is a valid cron expression
+	 */
+	public static boolean isValidExpression(String expression) {
+		String[] fields = StringUtils.tokenizeToStringArray(expression, " ");
+		return areValidCronFields(fields);
+	}
+
+	private static boolean areValidCronFields(String[] fields) {
+		return (fields != null && fields.length == 6);
+	}
+
+
 	@Override
 	public boolean equals(Object other) {
 		if (this == other) {

spring-context/src/test/java/org/springframework/scheduling/support/CronSequenceGeneratorTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -29,45 +29,46 @@ import static org.junit.Assert.*;
 public class CronSequenceGeneratorTests {
 
 	@Test
-	public void testAt50Seconds() {
+	public void at50Seconds() {
 		assertEquals(new Date(2012, 6, 2, 1, 0),
 				new CronSequenceGenerator("*/15 * 1-4 * * *").next(new Date(2012, 6, 1, 9, 53, 50)));
 	}
 
 	@Test
-	public void testAt0Seconds() {
+	public void at0Seconds() {
 		assertEquals(new Date(2012, 6, 2, 1, 0),
 				new CronSequenceGenerator("*/15 * 1-4 * * *").next(new Date(2012, 6, 1, 9, 53)));
 	}
 
 	@Test
-	public void testAt0Minutes() {
+	public void at0Minutes() {
 		assertEquals(new Date(2012, 6, 2, 1, 0),
 				new CronSequenceGenerator("0 */2 1-4 * * *").next(new Date(2012, 6, 1, 9, 0)));
 	}
 
 	@Test(expected = IllegalArgumentException.class)
-	public void testWith0Increment() {
+	public void with0Increment() {
 		new CronSequenceGenerator("*/0 * * * * *").next(new Date(2012, 6, 1, 9, 0));
 	}
 
 	@Test(expected = IllegalArgumentException.class)
-	public void testWithNegativeIncrement() {
+	public void withNegativeIncrement() {
 		new CronSequenceGenerator("*/-1 * * * * *").next(new Date(2012, 6, 1, 9, 0));
 	}
 
 	@Test
-	public void testValidExpression() {
+	public void validExpression() {
 		assertTrue(CronSequenceGenerator.isValidExpression("0 */2 1-4 * * *"));
 	}
 
 	@Test
-	public void testNotValidExpression() {
+	public void invalidExpression() {
 		assertFalse(CronSequenceGenerator.isValidExpression("0 */2 1-4 * * * *"));
 	}
 
 	@Test
-	public void testNullExpression() {
+	public void nullExpression() {
 		assertFalse(CronSequenceGenerator.isValidExpression(null));
 	}
+
 }