org.beangle.commons.entity.util

Class EntityUtils

java.lang.Object

org.beangle.commons.entity.util.EntityUtils

public final class EntityUtils
extends Object

实体类辅助工具箱

Version:

$Id: $

Author:

chaostone 2005-10-31

Method Summary

Modifier and Type	Method and Description
static void	evictEmptyProperty(Object entity) 清除实体类中引用的无效(外键)属性.
static <T extends Entity<?>> List<?>	extractIds(Collection<T> entities) extractIds.
static <T extends Entity<?>> String	extractIdSeq(Collection<T> entities) extractIdSeq.
static String	getCommandName(Class<?> clazz) getCommandName.
static String	getCommandName(Object obj) getCommandName.
static String	getCommandName(String entityName) getCommandName.
static String	getEntityClassName(Class<?> clazz) 为了取出CGLIB代来的代理命名
static boolean	isEmpty(Entity<?> entity, boolean ignoreDefault) 判断实体类中的属性是否全部为空
static boolean	isExpired(TemporalAt entity) isExpired.
static boolean	isExpired(TemporalOn entity)
static void	merge(Object dest, Object orig) Deprecated.
static void	populate(Map params, Entity entity)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

extractIds

public static <T extends Entity<?>> List<?> extractIds(Collection<T> entities)

extractIds.

Type Parameters:

T - a T object.

Parameters:

entities - a Collection object.

Returns:

a List object.

getCommandName

public static String getCommandName(Class<?> clazz)

getCommandName.

Parameters:

clazz - a Class object.

Returns:

a String object.

getCommandName

public static String getCommandName(String entityName)

getCommandName.

Parameters:

entityName - a String object.

Returns:

a String object.

getCommandName

public static String getCommandName(Object obj)

getCommandName.

Parameters:

obj - a Object object.

Returns:

a String object.

extractIdSeq

public static <T extends Entity<?>> String extractIdSeq(Collection<T> entities)

extractIdSeq.

Type Parameters:

T - a T object.

Parameters:

entities - a Collection object.

Returns:

a String object.

isEmpty

public static boolean isEmpty(Entity<?> entity,
                              boolean ignoreDefault)

判断实体类中的属性是否全部为空

Parameters:

entity - a Entity object.

ignoreDefault - 忽略数字和字符串的默认值

Returns:

a boolean.

getEntityClassName

public static String getEntityClassName(Class<?> clazz)

为了取出CGLIB代来的代理命名

Parameters:

clazz - a Class object.

Returns:

a String object.

isExpired

public static boolean isExpired(TemporalAt entity)

isExpired.

Parameters:

entity - a TemporalAt object.

Returns:

a boolean.

isExpired

public static boolean isExpired(TemporalOn entity)

evictEmptyProperty

public static void evictEmptyProperty(Object entity)

清除实体类中引用的无效(外键)属性.

  hibernate在保存对象是检查对象是否引用了未持久化的对象，如果引用则保存出错.
  实体类(Entity)是否已经持久化通过检查其id是否为有效值来判断的.
  对于实体类中包含的
 <code>
 Component
 </code>
  则递归处理
  因为集合为空仍有其含义，这里对集合不做随意处理.如
  // evict collection
  if (value instanceof Collection) {
    if (((Collection) value).isEmpty())
    map.put(attr, null);
  }
 

Parameters:

entity -

See Also:

ValidEntityPredicate

populate

public static void populate(Map params,
                            Entity entity)

merge

public static void merge(Object dest,
                         Object orig)

Deprecated.

    merge函数主要用来将页面回传对象(orig)的参数合并到数据库已经存在的对象中.（浅拷贝）
    合并的依据是待合并对象是否为空.如果对象是平面的component 则递归处理，如果是entity则检查是否是
    有效的持久化对象（id不为空或者0）,那么将该对象复制过去，否则复制null.

    这些页面对象中的集合属性不包括在复制和合并范围内.因为大多数页面参数中，很少有集合(Set)参数
    况且如果把空集合合并到已有对象上，反而会造成(hibernate)删除已有对象和这些对象的关联，甚至对象本身
    将orig中不为空的属性复制到dest中 added at
    两个对象必须是同一类型的
 

Parameters:

dest -

orig - 影响dest

See Also:

EntityUtil#evictEmptyProperty