1. 程式人生 > >java實現Object和Map之間的轉換3種方式

java實現Object和Map之間的轉換3種方式

1.利用commons.BeanUtils實現Obj和Map之間轉換,這種是最簡單,也是最經常用的

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);
}

2.利用java reflect完成Obj和Map之間的相互轉換

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;
}

3.利用Introspector完成Obj和Map之間的相互轉換

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;
    }