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 DoubleOperationTest extends GroovyTestCase {
				
				    def x
				    def y
				    
				    void testPlus() {
				        x = 2.1 + 2.1
				        assert x == 4.2
				        
				        x = 3 + 2.2
				        assert x == 5.2
				        
				        x = 2.2 + 4
				        assert x == 6.2
				        
				        y = x + 1
				        assert y == 7.2       
				        	
				        def z = y + x + 1 + 2
				        assert z == 16.4
				    }
				    
				    void testMinus() {
				        x = 6 - 2.2
				        assert x == 3.8
				        
				        x = 5.8 - 2
				        assert x == 3.8
				        
				        y = x - 1
						assert y == 2.8        
				    }
				    
				    void testMultiply() {
				        x = 3 * 2.0
				        assert x == 6.0
				        
				        x = 3.0 * 2
				        assert x == 6.0
				        
				        x = 3.0 * 2.0
				        assert x == 6.0
				        y = x * 2
				        assert y == 12.0        
				    }
				    
				    void testDivide() {
				        x = 80.0 / 4
				        assert x == 20.0 , "x = " + x
				        
				        x = 80 / 4.0
				        assert x == 20.0 , "x = " + x
				        
				        y = x / 2
				        assert y == 10.0 , "y = " + y     
				    }
				
				    void testMethodNotFound() {
				    	try {
				    		println( Math.sin("foo", 7) );
					    	fail("Should catch a MissingMethodException");
				    	} catch (MissingMethodException mme) {
				    	}
				    }
				        
				    void testCoerce() {
				    	def xyz = Math.sin(1.1);
				    	assert xyz instanceof Double;
				    	assert xyz == Math.sin(1.1D);
				    	
				        //Note that (7.3F).doubleValue() != 7.3D
				    	x = Math.sin(7.3F);
				    	assert x instanceof Double;
				    	assert x == Math.sin((7.3F).doubleValue());
				
				    	x = Math.sin(7);
				    	assert x instanceof Double;
				    	assert x == Math.sin(7.0D);
				    }
				}