package org.danyuan.application.common.utils;

import java.beans.BeanInfo;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;

/**
 * 当把Person类作为BeanUtilTest的内部类时,程序出错<br>
 * java.lang.NoSuchMethodException: Property '**' has no setter method<br>
 * 本质:内部类 和 单独文件中的类的区别 <br>
 * BeanUtils.populate方法的限制:<br>
 * The class must be public, and provide a public constructor that accepts no arguments. <br>
 * This allows tools and applications to dynamically create new instances of your bean, <br>
 * without necessarily knowing what Java class name will be used ahead of time
 */
public class BeanUtils {
	
	// Map --> Bean 1: 利用Introspector,PropertyDescriptor实现 Map --> Bean
	public static void transMap2Bean(Map<String, Object> map, Object obj) {

		try {
			BeanInfo beanInfo = Introspector.getBeanInfo(obj.getClass());
			PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();

			for (PropertyDescriptor property : propertyDescriptors) {
				String key = property.getName();

				if (map.containsKey(key)) {
					Object value = map.get(key);
					// 得到property对应的setter方法
					Method setter = property.getWriteMethod();
					setter.invoke(obj, value);
				}

			}

		} catch (Exception e) {
			System.out.println("transMap2Bean Error " + e);
		}

		return;

	}

	// Bean --> Map 1: 利用Introspector和PropertyDescriptor 将Bean --> Map
	public static Map<String, Object> transBean2Map(Object obj) {

		if (obj == null) {
			return null;
		}
		Map<String, Object> map = new HashMap<>();
		try {
			BeanInfo beanInfo = Introspector.getBeanInfo(obj.getClass());
			PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();
			for (PropertyDescriptor property : propertyDescriptors) {
				String key = property.getName();

				// 过滤class属性
				if (!key.equals("class")) {
					// 得到property对应的getter方法
					Method getter = property.getReadMethod();
					Object value = getter.invoke(obj);

					map.put(key, value);
				}

			}
		} catch (Exception e) {
			System.out.println("transBean2Map Error " + e);
		}

		return map;

	}
	
	// Bean --> Map 1: 利用Introspector和PropertyDescriptor 将Bean --> Map
	public static Map<String, String> transBean2MapStrMap(Object obj) {

		if (obj == null) {
			return null;
		}
		Map<String, String> map = new HashMap<>();
		try {
			BeanInfo beanInfo = Introspector.getBeanInfo(obj.getClass());
			PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();
			for (PropertyDescriptor property : propertyDescriptors) {
				String key = property.getName();

				// 过滤class属性
				if (!key.equals("class")) {
					// 得到property对应的getter方法
					Method getter = property.getReadMethod();
					String value = (String) getter.invoke(obj);

					map.put(key, value);
				}

			}
		} catch (Exception e) {
			System.out.println("transBean2Map Error " + e);
		}

		return map;

	}
	
}