Groovy动态语言 运行在JVM中的动态语言 可以方便的处理业务逻辑变化大的业务

				/**
				 * todo: add BreakContinueLabelWithClosureTest (when break is used to return from a Closure)
				
				 * @author Dierk Koenig
				 */
				class BreakContinueLabelTest extends GroovyTestCase {
				
				    void testDeclareSimpleLabel() {
				        label_1: assert true
				        label_2:
				        assert true
				    }
				    void testBreakLabelInSimpleForLoop() {
				        label_1: for (i in [1]) {
				            break label_1
				            assert false
				        }
				    }
				
				    void testBreakLabelInNestedForLoop() {
				        label: for (i in [1]) {
				            for (j in [1]){
				                break label
				                assert false, 'did not break inner loop'
				            }
				            assert false, 'did not break outer loop'
				        }
				    }
				
				    void testUnlabelledBreakInNestedForLoop() {
				        def reached = false
				        for (i in [1]) {
				            for (j in [1]){
				                break
				                assert false, 'did not break inner loop'
				            }
				            reached = true
				        }
				        assert reached, 'must not break outer loop'
				    }
				
				    void testBreakLabelInSimpleWhileLoop() {
				        label_1: while (true) {
				            break label_1
				            assert false
				        }
				    }
				
				    void testBreakLabelInNestedWhileLoop() {
				        def count = 0
				        label: while (count < 1) {
				            count++
				            while (true){
				                break label
				                assert false, 'did not break inner loop'
				            }
				            assert false, 'did not break outer loop'
				        }
				    }
				
				    void testBreakLabelInNestedMixedForAndWhileLoop() {
				        def count = 0
				        label_1: while (count < 1) {
				            count++
				            for (i in [1]){
				                break label_1
				                assert false, 'did not break inner loop'
				            }
				            assert false, 'did not break outer loop'
				        }
				        label_2: for (i in [1]) {
				            while (true){
				                break label_2
				                assert false, 'did not break inner loop'
				            }
				            assert false, 'did not break outer loop'
				        }
				    }
				
				    void testUnlabelledContinueInNestedForLoop() {
				        def log = ''
				        for (i in [1,2]) {
				            log += i
				            for (j in [3,4]){
				                if (j==3) continue
				                log += j
				            }
				        }
				        assertEquals '1424',log
				    }
				
				    void testContinueLabelInNestedForLoop() {
				        def log = ''
				        label: for (i in [1,2]) {
				            log += i
				            for (j in [3,4]){
				                if (j==4) continue label
				                log += j
				            }
				            log += 'never reached'
				        }
				        assertEquals '1323',log
				    }
				}