java 对象转map，map转对象

java对象转map：

/**
	 * JavaBean对象转化成Map对象
	 * 
	 * @param javaBean
	 * @return
	 */
	@SuppressWarnings({ "rawtypes", "unchecked" })
	public static Map java2Map(Object javaBean) {
		Map map = new HashMap();
		try {
			// 获取javaBean属性
			BeanInfo beanInfo = Introspector.getBeanInfo(javaBean.getClass());

			PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();
			if (propertyDescriptors != null && propertyDescriptors.length > 0) {
				String propertyName = null; // javaBean属性名
				Object propertyValue = null; // javaBean属性值
				for (PropertyDescriptor pd : propertyDescriptors) {
					propertyName = pd.getName();
					if (!propertyName.equals("class")) {
						Method readMethod = pd.getReadMethod();
						propertyValue = readMethod.invoke(javaBean, new Object[0]);
						map.put(propertyName, propertyValue);
					}
				}
			}

		} catch (Exception e) {
			e.printStackTrace();
		}
		return map;
	}

map转java对象：

/**
	 * map转换为对象
	 * 
	 * @param clazz
	 * @param map
	 * @return
	 */
	@SuppressWarnings("rawtypes")
	private static <T> T toBean(Class<T> clazz, Map map) {
		T obj = null;
		try {
			BeanInfo beanInfo = Introspector.getBeanInfo(clazz);
			obj = clazz.newInstance(); // 创建 JavaBean 对象
			// 给 JavaBean 对象的属性赋值
			PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();
			for (int i = 0; i < propertyDescriptors.length; i++) {
				PropertyDescriptor descriptor = propertyDescriptors[i];
				String propertyName = descriptor.getName();
				if (map.containsKey(propertyName)) {
					// 下面一句可以 try 起来，这样当一个属性赋值失败的时候就不会影响其他属性赋值。
					Object value = map.get(propertyName);
					if ("".equals(value)) {
						value = null;
					}
					Object[] args = new Object[1];
					args[0] = value;
					try {
						descriptor.getWriteMethod().invoke(obj, args);
					} catch (InvocationTargetException e) {
						System.out.println("字段映射失败");
					}
				}
			}
		} catch (IllegalAccessException e) {
			System.out.println("实例化 JavaBean 失败");
		} catch (IntrospectionException e) {
			System.out.println("分析类属性失败");
		} catch (IllegalArgumentException e) {
			System.out.println(e.getMessage());
			System.out.println("映射错误");
		} catch (InstantiationException e) {
			System.out.println("实例化 JavaBean 失败");
		}
		return (T) obj;
	}