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

				class MinusEqualsTest extends GroovyTestCase {
				
				    void testIntegerMinusEquals() {
				        def x = 4
				        def y = 2
				        x -= y
				        
				        assert x == 2
				        
				        y -= 1
				        
				        assert y == 1
				    }
				
				    void testCharacterMinusEquals() {
				        Character x = 4
				        Character y = 2
				        x -= y
				        
				        assert x == 2
				        
				        y -= 1
				        
				        assert y == 1
				    }
				    
				    void testNumberMinusEquals() {
				        def x = 4.2
				        def y = 2
				        x -= y
				        
				        assert x == 2.2
				        
				        y -= 0.1
				        
				        assert y == 1.9
				    }
				    
				    void testStringMinusEquals() {
				        def foo = "nice cheese"
				        foo -= "cheese"
				        
				        assert foo == "nice "
				    }
				}