java implements conversion between Object and Map in three ways

Using commons.BeanUtils to convert between Obj and Map is the simplest and most frequently used

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);
  }

The conversion between Obj and Map is accomplished by using java reflect

    public Map<String,Object> Obj2Map(Object obj) throws Exception{
      Map<String,Object> map=new HashMap<String, Object>();
      Field[] fields = obj.getClass().getDeclaredFields();
      for(Field field:fields){
        field.setAccessible(true);
        map.put(field.getName(), field.get(obj));
      }
      return map;
    }
    public Object map2Obj(Map<String,Object> map,Class<?> clz) throws Exception{
      Object obj = clz.newInstance();
      Field[] declaredFields = obj.getClass().getDeclaredFields();
      for(Field field:declaredFields){
        int mod = field.getModifiers(); 
        if(Modifier.isStatic(mod) || Modifier.isFinal(mod)){
          continue;
        }
        field.setAccessible(true);
        field.set(obj, map.get(field.getName()));
      }
      return obj;
    }

The conversion between Obj and Map is accomplished by USING Introspector

public Map<String,Object> obj2Map(Object obj) throws Exception{
      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;
    }
    
    public Object map2Obj(Map<String,Object> map,Class<?> clz) throws Exception{
      if (map == null)  
        return null;  
      Object obj = clz.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;
    }