javabean與map的轉換有很多種方式,比如:
1、通過json工具先將bean轉換爲json,再將json轉換爲map,這種方式效率很低,不推薦
2、通過java反射,獲取bean類的屬性和值,再轉換到map對應的鍵值對中,這種方法次之,但稍微有點麻煩,不推薦
3、通過net.sf.cglib.beans.BeanMap類中的方法,這種方式效率極高,該方式利用Java反射和緩存,初次創建bean時需要初始化,之後就使用緩存,所以速度極快。
附上代碼(也可以轉換List):
mport java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import net.sf.cglib.beans.BeanMap;
public class BeanMapUtils {
/**
* 將對象裝換爲map
*
* @param bean
* @return
*/
public static <T> Map<String, Object> beanToMap(T bean) {
Map<String, Object> map = new HashMap<>();
if (bean != null) {
BeanMap beanMap = BeanMap.create(bean);
for (Object key : beanMap.keySet()) {
map.put(key + "", beanMap.get(key));
}
}
return map;
}
/**
* 將map裝換爲javabean對象
*
* @param map
* @param bean
* @return
*/
public static <T> T mapToBean(Map<String, Object> map, T bean) {
BeanMap beanMap = BeanMap.create(bean);
beanMap.putAll(map);
return bean;
}
/**
* 將List<T>轉換爲List<Map<String, Object>>
*
* @param objList
* @return
*/
public static <T> List<Map<String, Object>> objectsToMaps(List<T> objList) {
List<Map<String, Object>> list = new ArrayList<>();
if (objList != null && objList.size() > 0) {
Map<String, Object> map = null;
T bean = null;
for (int i = 0, size = objList.size(); i < size; i++) {
bean = objList.get(i);
map = beanToMap(bean);
list.add(map);
}
}
return list;
}
/**
* 將List<Map<String,Object>>轉換爲List<T>
*
* @param maps
* @param clazz
* @return
* @throws InstantiationException
* @throws IllegalAccessException
*/
public static <T> List<T> mapsToObjects(List<Map<String, Object>> maps, Class<T> clazz)
throws InstantiationException, IllegalAccessException {
List<T> list = new ArrayList<>();
if (maps != null && maps.size() > 0) {
Map<String, Object> map = null;
T bean = null;
for (int i = 0, size = maps.size(); i < size; i++) {
map = maps.get(i);
bean = clazz.newInstance();
mapToBean(map, bean);
list.add(bean);
}
}
return list;
}
}