类的反向实例化，分离类的属性名和属性值（Java）

一个关于类（Object）转换问题的类：

可以将一个类或对象的属性名和属性值分离出来，不使用XML技术，有点像“类的反向实例化”（自己取的名字^_^）

 

包含了一些常用方法，必要的大家可以自行增加。

 

package engin;import java.lang.reflect.Field;import java.sql.Timestamp;import java.text.SimpleDateFormat;import java.util.Date;import java.util.HashMap;import java.util.Iterator;import java.util.Map;import java.util.Set;import entity.Song;public class ObjectUtils {/** * 将指定对象属性名称和属性值转化为Map键值对 * * @param obj * @return */public static HashMap objectToMap(Object obj) throws Exception {if (obj == null) {throw new Exception("对象为空");}Class clazz = obj.getClass();HashMap map = new HashMap();getClass(clazz,map,obj);HashMap newMap = convertHashMap(map);return newMap;}/** * 带入一个对象，一个对象中的属性名称，取得该属性的值 * @param obj * @param strProperty * @return * @throws Exception */public static String getPropertyValueFormObject(Object obj,String strProperty) throws Exception {HashMap newMap = ObjectUtils.objectToMap(obj);if (newMap == null) {return "";} else {Object objReturn = newMap.get(strProperty);if (objReturn==null) {return "";} else {return objReturn.toString();}}}/** **/private static void getClass(Class clazz,HashMap map,Object obj) throws Exception{if(clazz.getSimpleName().equals("Object")){return;}Field[] fields = clazz.getDeclaredFields();if (fields == null || fields.length <= 0) {throw new Exception("当前对象中没有任何属性值");}for(int i=0;i<fields.length;i++){fields[i].setAccessible(true);String name=fields[i].getName();Object value=fields[i].get(obj);map.put(name,value);}Class superClzz=clazz.getSuperclass();getClass(superClzz,map,obj);}/** * * @param map * @return * @throws Exception */private static HashMap convertHashMap(HashMap map) throws Exception {HashMap newMap = new HashMap();Set keys = map.keySet();Iterator it = keys.iterator();while (it.hasNext()) {Object key = it.next();convertToString(map.get(key), newMap, key);}return newMap;}/** * * @param value * @param newMap * @param key */private static void convertToString(Object value, HashMap newMap, Object key) {if (value != null) {Class clazz = value.getClass();if (isBaseType(clazz)) {newMap.put(key, value.toString());} else if (clazz == String.class) {newMap.put(key, value.toString());} else if (clazz == Date.class) {Date date = (Date) value;SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");newMap.put(key, sdf.format(date));} else if (clazz == Timestamp.class) {Timestamp timestamp = (Timestamp) value;long times = timestamp.getTime();Date date = new Date(times);SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");newMap.put(key, sdf.format(date));} else if (clazz == java.sql.Date.class) {java.sql.Date sqlDate = (java.sql.Date) value;SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");newMap.put(key, sdf.format(sqlDate));} else {newMap.put(key, value);}} else {newMap.put(key, value);}}/** * * @param clazz * @return */private static boolean isBaseType(Class clazz) {if (clazz == Integer.class) {return true;}if (clazz == Long.class) {return true;}if (clazz == Double.class) {return true;}if (clazz == Byte.class) {return true;}if (clazz == Float.class) {return true;}if (clazz == Short.class) {return true;}if (clazz == Boolean.class) {return true;}return false;}public static Iterator getObjectElements(Object obj) throws Exception{HashMap map = ObjectUtils.objectToMap(obj);Set entrys = map.entrySet();return entrys.iterator();}/** * 测试 * * @param args */public static void main(String args[]) throws Exception {Song song = new Song();song.setId(1);Object obj=song;Iterator it = getObjectElements(obj);while (it.hasNext()) {Map.Entry entry = (Map.Entry) it.next();System.out.println(entry.getKey() + ":" + entry.getValue());}}}