Java如何填充对象中的时间属性呢?
前提:不知道对象具体类型.
解决方法:使用反射
Java代码
- /***
- * 把对象中的列,类型为时间的都设置为当前时间
- * @param obj
- * @throws SecurityException
- * @throws NoSuchFieldException
- * @throws IllegalArgumentException
- * @throws IllegalAccessException
- */
- public static void fillTimeForObj(Object obj) throws SecurityException, NoSuchFieldException, IllegalArgumentException, IllegalAccessException{
- List<Field> fieldsList=getAllFieldList(obj.getClass());
- int size=fieldsList.size();
- for(int i=0;i<size;i++){
- Field f=fieldsList.get(i);
- String typeName=f.getType().getName();
- if(typeName.equals("java.sql.Timestamp")||typeName.equals("java.util.Date")){
- setObjectValue(obj, f, TimeHWUtil.getCurrentTimestamp());
- }else if(typeName.equals("java.sql.Date")){
- setObjectValue(obj, f, new java.util.Date());
- }
- }
- }
依赖的方法:
Java代码
- /***
- * get all field ,including fields in father/super class
- *
- * @param clazz
- * @return
- */
- public static List<Field> getAllFieldList(Class<?> clazz) {
- List<Field> fieldsList = new ArrayList<Field>();// return object
- if (clazz == null) {
- return null;
- }
- Class<?> superClass = clazz.getSuperclass();// father class
- if (!superClass.getName().equals(Object.class.getName()))/*
- * java.lang.Object
- */{
- // System.out.println("has father");
- fieldsList.addAll(getAllFieldList(superClass));// Recursive
- }
- Field[] fields = clazz.getDeclaredFields();
- for (int i = 0; i < fields.length; i++) {
- Field field = fields[i];
- // 排除因实现Serializable 接口而产生的属性serialVersionUID
- if (!field.getName().equals("serialVersionUID")) {
- fieldsList.add(field);
- }
- }
- return fieldsList;
- }
- /***
- * 设置对象的属性值。
- *
- * @param obj
- * @param propertyName
- * : property name
- * @param propertyValue
- * : value of property<br> must be String or Field
- * @throws SecurityException
- * @throws NoSuchFieldException
- * @throws IllegalArgumentException
- * @throws IllegalAccessException
- */
- public static void setObjectValue(Object obj, Object propertyName,
- Object propertyValue) throws SecurityException,
- NoSuchFieldException, IllegalArgumentException,
- IllegalAccessException {
- if (ValueWidget.isNullOrEmpty(propertyName)
- || ValueWidget.isNullOrEmpty (propertyValue)) {
- return;
- }
- Class<?> clazz = obj.getClass();
- Field name = null;
- if(propertyName instanceof String){
- name=getSpecifiedField(clazz, (String)propertyName);
- }else{
- name=(Field)propertyName;
- }
- name.setAccessible(true);
- name.set(obj, propertyValue);
- }
- /***
- * Get Specified Field
- *
- * @param clazz
- * @param fieldName
- * @return
- */
- public static Field getSpecifiedField(Class<?> clazz, String fieldName) {
- Field f = null;
- if (ValueWidget.isNullOrEmpty(clazz)) {
- return null;
- }
- try {
- f = clazz.getDeclaredField(fieldName);
- } catch (NoSuchFieldException e) {
- return getSpecifiedField(clazz.getSuperclass()/*
- * may be null if it is
- * Object .
- */, fieldName);
- // e.printStackTrace();
- }
- return f;
- }
把A对象的时间属性的值设置到B对象中
Java代码
- /***
- * 使用spring MVC保存对象时,对象的createTime(时间类型的属性)没有注入进来,
- * <br>这时需要后台先通过id获取持久化对象,然后手动注入
- * @param editedObj
- * @param persistentObj
- * @throws SecurityException
- * @throws NoSuchFieldException
- * @throws IllegalArgumentException
- * @throws IllegalAccessException
- */
- public static void fillTimeForEditedObj(Object editedObj,Object persistentObj) throws SecurityException, NoSuchFieldException, IllegalArgumentException, IllegalAccessException{
- if(!editedObj.getClass().getName().equals(persistentObj.getClass().getName())){
- throw new RuntimeException("Two object type should be the same ,but is different .");
- }
- List<Field> fieldsList=getAllFieldList(editedObj.getClass());
- int size=fieldsList.size();
- for(int i=0;i<size;i++){
- Field f=fieldsList.get(i);
- String typeName=f.getType().getName();
- if(editedObj instanceof java.util.Date || typeName.equals("java.sql.Timestamp")||typeName.equals("java.util.Date")||typeName.equals("java.sql.Date")){
- Object valueEdited=getObjectValue(editedObj, f);
- Object valuePersistent=getObjectValue(persistentObj, f);
- if(ValueWidget.isNullOrEmpty(valueEdited)&&(!ValueWidget.isNullOrEmpty(valuePersistent))){
- setObjectValue(editedObj, f, valuePersistent);
- }
- }
- }
- }
参考:
