java实现map和object互转的三种方法

/**

 * 使用org.apache.commons.beanutils进行转换

 */ 

class A { 

       

    public static Object mapToObject(Map<String, Object> map, Class<?> beanClass) throws Exception {   

        if (map == null) 

            return null; 

   

        Object obj = beanClass.newInstance(); 

   

        org.apache.commons.beanutils.BeanUtils.populate(obj, map); 

   

        return obj; 

    }   

       

    public static Map<?, ?> objectToMap(Object obj) { 

        if(obj == null) 

            return null;  

   

        return new org.apache.commons.beanutils.BeanMap(obj); 

    }   

       

} 

   

/**

 * 使用Introspector进行转换

 */ 

class B { 

   

    public static Object mapToObject(Map<String, Object> map, Class<?> beanClass) throws Exception {   

        if (map == null)  

            return null;   

   

        Object obj = beanClass.newInstance(); 

   

        BeanInfo beanInfo = Introspector.getBeanInfo(obj.getClass());   

        PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();   

        for (PropertyDescriptor property : propertyDescriptors) { 

            Method setter = property.getWriteMethod();   

            if (setter != null) { 

                setter.invoke(obj, map.get(property.getName()));  

            } 

        } 

   

        return obj; 

    }   

       

    public static Map<String, Object> objectToMap(Object obj) throws Exception {   

        if(obj == null) 

            return null;     

   

        Map<String, Object> map = new HashMap<String, Object>();  

   

        BeanInfo beanInfo = Introspector.getBeanInfo(obj.getClass());   

        PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();   

        for (PropertyDescriptor property : propertyDescriptors) {   

            String key = property.getName();   

            if (key.compareToIgnoreCase("class") == 0) {  

                continue; 

            } 

            Method getter = property.getReadMethod(); 

            Object value = getter!=null ? getter.invoke(obj) : null; 

            map.put(key, value); 

        }   

   

        return map; 

    }   

       

} 

   

/**

 * 使用reflect进行转换

 */ 

class C { 

   

    public static Object mapToObject(Map<String, Object> map, Class<?> beanClass) throws Exception {   

        if (map == null) 

            return null;   

   

        Object obj = beanClass.newInstance(); 

   

        Field[] fields = obj.getClass().getDeclaredFields();  

        for (Field field : fields) {   

            int mod = field.getModifiers();   

            if(Modifier.isStatic(mod) || Modifier.isFinal(mod)){   

                continue;   

            }   

   

            field.setAccessible(true);   

            field.set(obj, map.get(field.getName()));  

        }  

   

        return obj;   

    }   

   

    public static Map<String, Object> objectToMap(Object obj) throws Exception {   

        if(obj == null){   

            return null;   

        }  

   

        Map<String, Object> map = new HashMap<String, Object>();   

   

        Field[] declaredFields = obj.getClass().getDeclaredFields();   

        for (Field field : declaredFields) {   

            field.setAccessible(true); 

            map.put(field.getName(), field.get(obj)); 

        }   

   

        return map; 

    }  

}