Map与JavaBean之间相互转化

反射可以操作各种不同的Java类，而内省只是通过反射来操作JavaBean的。

内省

public Map<String, Object> beanToMap(Object bean) {
    Map<String, Object> map = new HashMap();

    try {
        BeanInfo beanInfo = Introspector.getBeanInfo(bean.getClass(), Object.class);
        PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();

        for (PropertyDescriptor propertyDescriptor : propertyDescriptors) {
            String key = propertyDescriptor.getName();
            Object value = propertyDescriptor.getReadMethod().invoke(bean);
            map.put(key, value);
        }

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

    return map;
}

public <T> T mapToBean(Map<String, Object> map, Class<T> beanType) {
    T bean = null;

    try {
        bean = beanType.newInstance();
        BeanInfo beanInfo = Introspector.getBeanInfo(beanType, Object.class);
        PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();

        for (PropertyDescriptor propertyDescriptor : propertyDescriptors) {
            String key = propertyDescriptor.getName();
            Object value = map.get(key);
            propertyDescriptor.getWriteMethod().invoke(bean, value);
        }

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

    return bean;
}

反射

public Map<String, Object> beanToMap(Object bean) {
    Map<String, Object> map = new HashMap();

    try {
        Class cls = bean.getClass();
        Field[] fields = cls.getDeclaredFields();

        for (Field field : fields) {
            field.setAccessible(true);
            String key = field.getName();
            Object value = field.get(bean);
            map.put(key, value);
        }

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

    return map;
}

public <T> T mapToBean(Map<String, Object> map, Class<T> beanType) {
    T bean = null;

    try {
        bean = beanType.newInstance();

        for (String key : map.keySet()) {
            Object value = map.get(key);
            Field field = beanType.getDeclaredField(key);
            field.setAccessible(true);
            field.set(bean, value);
        }

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

    return bean;
}