java高新技术-操作javaBean

public class IntroSpectorTest {

    public static void main(String[] args) throws Exception{
        ReflectPoint pt1 = new ReflectPoint(3, 5);
        
        String propertyName = "x";
        //"x" --> "X" -->"getX" --> MethodGetX-->
        Object retVal = getProperty(pt1, propertyName);
        System.out.println(retVal);
        
        Object value = 7;
        setProperties(pt1, propertyName, value);
        
        System.out.println(pt1.getX());
    }
    
    private static Object getProperty(Object pt1, String propertyName) throws Exception{
        PropertyDescriptor pd = new PropertyDescriptor(propertyName, pt1.getClass());
        Method methodGetX = pd.getReadMethod();
        Object retVal = methodGetX.invoke(pt1);
        return retVal;
    }
    
    private static void setProperties(Object pt1, String propertyName, Object value) throws Exception{
        PropertyDescriptor pd = new PropertyDescriptor(propertyName, pt1.getClass());
        Method methodSetX = pd.getWriteMethod();
        methodSetX.invoke(pt1, value);
    }
}

private static Object getProperty(Object pt1, String propertyName) throws Exception{
//        PropertyDescriptor pd = new PropertyDescriptor(propertyName, pt1.getClass());
//        Method methodGetX = pd.getReadMethod();
//        Object retVal = methodGetX.invoke(pt1);
        
        //采用复杂的方式
        //把一个普通类当作javaBean来看待
        BeanInfo beanInfo = Introspector.getBeanInfo(pt1.getClass());
        PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();
        Object retVal = null;
        for(PropertyDescriptor pd : propertyDescriptors){
            if(pd.getName().equals(propertyName)){
                Method readMethod = pd.getReadMethod();
                retVal = readMethod.invoke(pt1);
                break;
            }
        }
        return retVal;
    }

/**
         * 使用BeanUtils
         * 设置属性和获取值使用的是字符串，1.自动完成类型的转换
         */
        System.out.println(BeanUtils.getProperty(pt1, "x").getClass().getName());
        BeanUtils.setProperty(pt1, "x", "9");
        System.out.println(pt1.getX());
        
        //2.支持属性的级联操作
        BeanUtils.setProperty(pt1, "birthday.time", "111");
        System.out.println(BeanUtils.getProperty(pt1, "birthday.time"));

static void    copyProperties(Object dest, Object orig) 
          Copy property values from the origin bean to the destination bean for all cases where the property names are the same.

static Map    describe(Object bean) 
          Return the entire set of properties for which the specified bean provides a read method.

static void    populate(Object bean, Map properties) 
          Populate the JavaBeans properties of the specified bean, based on the specified name/value pairs

//使用PropertyUtils
        PropertyUtils.setProperty(pt1, "x", 9);
        System.out.println(PropertyUtils.getProperty(pt1, "x").getClass()
                .getName());