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
?
/***
* 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:
?
?
/***
* 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
/***
* 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:
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原文：http://hw1287789687.iteye.com/blog/2154705