對javabean的簡單內省和複雜內省操作

1、對javabean的簡單內省操作

使用PropertyDescriptor類，它代表的javabean的屬性，封裝的是屬性的信息

代碼示例：

package cn.itcast.IntroSpector; import itcast.cn.Reflect.ReflectPoint; import java.beans.BeanInfo; import java.beans.IntrospectionException; import java.beans.Introspector; import java.beans.PropertyDescriptor; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import org.apache.commons.beanutils.BeanUtils; public class TestIntroSpector { public static void main(String[] args) throws Exception { // TODO Auto-generated method stub ReflectPoint rp = new ReflectPoint(3, 5); //使用內省方法 String propertyName = "x"; // 屬性名爲x Object retValue = getPropery(rp, propertyName); System.out.println(retValue); Object value = 8; PropertyDescriptor dp = new PropertyDescriptor(propertyName, rp.getClass()); Method methodSetX = dp.getWriteMethod(); methodSetX.invoke(rp, value); System.out.println(rp.getX()); } }

 

2、對javabean的複雜內省操作 （使用IntroSpectorle類， BeanInfo類， InstroSpector.getBeanInfo方法）

package cn.itcast.IntroSpector; import itcast.cn.Reflect.ReflectPoint; import java.beans.BeanInfo; import java.beans.IntrospectionException; import java.beans.Introspector; import java.beans.PropertyDescriptor; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import org.apache.commons.beanutils.BeanUtils; public class TestIntroSpector { public static void main(String[] args) throws Exception { // TODO Auto-generated method stub ReflectPoint rp = new ReflectPoint(3, 5); //使用內省方法 String propertyName = "x"; // 屬性名爲x Object retValue = getPropery(rp, propertyName); System.out.println(retValue); } /** * @param rp * @param propertyName * @return * @throws IntrospectionException * @throws IllegalAccessException * @throws InvocationTargetException */ private static Object getPropery(Object obj, String propertyName) throws IntrospectionException, IllegalAccessException, InvocationTargetException { /*PropertyDescriptor pd = new PropertyDescriptor(propertyName, rp.getClass()); Method methodGetX = pd.getReadMethod(); Object retValue = methodGetX.invoke(rp);*/ BeanInfo beanInfo = Introspector.getBeanInfo(obj.getClass()); PropertyDescriptor[] pds = beanInfo.getPropertyDescriptors(); Object retValue = null; for (PropertyDescriptor pd : pds) { if (pd.getName().equals(propertyName)) { Method methodGetX = pd.getReadMethod(); retValue = methodGetX.invoke(obj); } } return retValue; } }