java实现map和object互转的三种方法详解编程语言

/**  
 * 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;   
    }    
}