java實現map和object互轉的三種方法

/**


使用org.apache.commons.beanutils進行轉換 
*/

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進行轉換 
*/

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進行轉換 
*/

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;  

}

}  </pre>