java 对象属性转list_java将对象列表中的某个属性转换成List或Map
/**
* @Description 对象属性操作工具类
* @Package com.viathink.msswms.sample.utils.PropertiesUtils.java
* @author LiuJunGuang
* @date 2012-5-11 下午1:54:08
* @version V1.0
*/
public class PropertiesUtils {
/**
* 根据对象列表和对象的某个属性返回属性的List集合
*
* @param objList
* 对象列表
* @param propertyName
* 要操作的属性名称
* @return
* 指定属性的List集合;
* 如果objList为null或者size等于0抛出 IllegalArgumentException异常;
* 如果propertyName为null抛出 IllegalArgumentException异常
*
* @throws NoSuchMethodException
* @throws InvocationTargetException
*/
public static List getPropertyList(List objList, String propertyName) throws IllegalAccessException,
InvocationTargetException, NoSuchMethodException {
if (objList == null || objList.size() == 0)
throw new IllegalArgumentException("No objList specified");
if (propertyName == null || "".equals(propertyName)) {
throw new IllegalArgumentException("No propertyName specified for bean class '" + objList.get(0).getClass() + "'");
}
PropertyUtilsBean p = new PropertyUtilsBean();
List propList = new LinkedList();
for (int i = 0; i < objList.size(); i++) {
T obj = objList.get(i);
propList.add(p.getProperty(obj, propertyName));
}
return propList;
}
/**
* 将List列表中的对象的某个属性封装成一个Map对象，key值是属性名，value值是对象列表中对象属性值的列表
*
* @param objList
* 对象列表
* @param propertyName
* 属性名称,可以是一个或者多个
* @return 返回封装了属性名称和属性值列表的Map对象，如果参数非法则抛出异常信息
* @throws IllegalAccessException
* @throws InvocationTargetException
* @throws NoSuchMethodException
*/
public static Map> getPropertiesMap(List objList, String... propertyName)
throws IllegalAccessException, InvocationTargetException, NoSuchMethodException {
if (objList == null || objList.size() == 0)
throw new IllegalArgumentException("No objList specified");
if (propertyName == null || propertyName.length == 0) {
throw new IllegalArgumentException("No propertyName specified for bean class '" + objList.get(0).getClass() + "'");
}
Map> maps = new HashMap>();
for (int i = 0; i < propertyName.length; i++) {
maps.put(propertyName[i], getPropertyList(objList, propertyName[i]));
}
return maps;
}
}用到BeanUtils工具包