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 <pre> * 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 * </pre> * @throws NoSuchMethodException * @throws InvocationTargetException */public static <T> List<Object> getPropertyList(List<T> 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<Object> propList = new LinkedList<Object>();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 <T> Map<String, List<Object>> getPropertiesMap(List<T> 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<String, List<Object>> maps = new HashMap<String, List<Object>>();for (int i = 0; i < propertyName.length; i++) {maps.put(propertyName[i], getPropertyList(objList, propertyName[i]));}return maps;}}

用到BeanUtils工具包