Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 fvZ[eJ
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 \S)cVp)h
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据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 fI-f Gx
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 v=?/c-J*
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分页支持类: Qsr+f~"W
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java代码: NnO%D^P]
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package com.javaeye.common.util; GBGna3
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import java.util.List; x{$/|_
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publicclass PaginationSupport { [g$IN/o%
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publicfinalstaticint PAGESIZE = 30; V_jGL<X|
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privateint pageSize = PAGESIZE; $x(p:+TI\4
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privateList items; ZEG~ek=jM
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privateint totalCount; Z>ztFU
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privateint[] indexes = newint[0]; :hDv^D?3
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privateint startIndex = 0; 'LG
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public PaginationSupport(List items, int Z#s-(wf
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totalCount){ ?fNUmk^A<
setPageSize(PAGESIZE); G-Zn-I
setTotalCount(totalCount); TZa LB}4
setItems(items); t7,** $ST
setStartIndex(0); !s[gv1
} 8,]wOxwqi
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public PaginationSupport(List items, int /7K7o8g
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totalCount, int startIndex){ G Cp90
setPageSize(PAGESIZE); d"}lh:L9
setTotalCount(totalCount); gyOAvx
setItems(items); <P-AlHYV-
setStartIndex(startIndex); a#+;BH1
} #[y2nK3zF
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public PaginationSupport(List items, int *):s**BJ$
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totalCount, int pageSize, int startIndex){ 1A N)%
setPageSize(pageSize); @g1T??h
setTotalCount(totalCount); kf_*=ER
setItems(items); iy|xF~
setStartIndex(startIndex); =+"-8tz8FV
} ro18%'RRI
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publicList getItems(){ j.KV:zJU
return items; ^[1Xl7)`
} r9~I R
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publicvoid setItems(List items){ rz5@E
this.items = items; "tmr
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} JgcMk]|'
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publicint getPageSize(){ Q,R|VI6Co
return pageSize; d@
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} 1c:/c|shQ_
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publicvoid setPageSize(int pageSize){ +l>X Z
this.pageSize = pageSize; Q8NrbMrl
} gX/?
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publicint getTotalCount(){ 9zaSA,}
return totalCount; Hx ojxZwm
} }XRRM:B|)(
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publicvoid setTotalCount(int totalCount){ QMwV6cA
if(totalCount > 0){ |S3wCG
this.totalCount = totalCount; [V41 Gk
int count = totalCount / zO 6Sl[)
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pageSize; _>G=xKA#e
if(totalCount % pageSize > 0) M>@PRb:Oc
count++; +e&Q<q!,q
indexes = newint[count]; f&C]}P
for(int i = 0; i < count; i++){ aTE;Gy,W
indexes = pageSize * 4J$dG l#f
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} ^PowL:
}else{ }*vO&J@z
this.totalCount = 0; _sF
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} 0#/Pc`zC
} cfPQcB>A
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publicint[] getIndexes(){ mWH;-F*%
return indexes; *NQsD C.J^
} /(Ryh6M
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publicvoid setIndexes(int[] indexes){ u(4o#m
this.indexes = indexes; O
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publicint getStartIndex(){ je=XZ's,i~
return startIndex; me@EKspX
} ]wV_xZ)l^A
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publicvoid setStartIndex(int startIndex){ "qw.{{:tf
if(totalCount <= 0) [ejl #'*5
this.startIndex = 0; `B7? F$J
elseif(startIndex >= totalCount) ZnD(RM
this.startIndex = indexes i{k v$ir!
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[indexes.length - 1]; %DhLU~VX
elseif(startIndex < 0) tdn|mX#
this.startIndex = 0; l"9$lF}
else{ uar[D|DcD"
this.startIndex = indexes -FQS5Zb.!
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[startIndex / pageSize]; MMf_
} ilFS9A3P
} tj[-|h
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publicint getNextIndex(){ d6~d)E
int nextIndex = getStartIndex() + 0mI4hy
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pageSize; i&JI"Dd7
if(nextIndex >= totalCount) z=DK(b;$z
return getStartIndex(); M.KXDD#O
else Ir3|PehB
return nextIndex; \,yg@R
} 9a{9|p>L
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publicint getPreviousIndex(){ da5fKK/s
int previousIndex = getStartIndex() - fx/If
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pageSize; N1X;&qZDd
if(previousIndex < 0) z2OXCZ*/
return0; 2m2$jp0
else +<f!#4T
return previousIndex; p *GAs
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} q:G3y[ P
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} g
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抽象业务类 61`tQFx,
java代码: "S3U]zw0_
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/** WFMQ;
* Created on 2005-7-12 A]m_&A#
*/ M[KYt"v
package com.javaeye.common.business; [I%'\CI;
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import java.io.Serializable; ?/24-n
import java.util.List; F1&7m
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import org.hibernate.Criteria; "nC=.5/$
import org.hibernate.HibernateException; /{nZI_v#
import org.hibernate.Session; r }Nq"s<
import org.hibernate.criterion.DetachedCriteria; wI2fCq(a0
import org.hibernate.criterion.Projections; 2Q[q)u
import i-Ri;E
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org.springframework.orm.hibernate3.HibernateCallback; [,q^\T
import %YI !{
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org.springframework.orm.hibernate3.support.HibernateDaoS $lf\1)B~*
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upport; zl["}I(*n
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import com.javaeye.common.util.PaginationSupport; BaE}|4
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public abstract class AbstractManager extends @RLlkWGc
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HibernateDaoSupport { LQ4F/[1}
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privateboolean cacheQueries = false; $ 7uxReFZR
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privateString queryCacheRegion; 2Jn?'76`
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publicvoid setCacheQueries(boolean LrnE6U9
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cacheQueries){ \t]aBT,
this.cacheQueries = cacheQueries;
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} 3G-f+HN^E
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publicvoid setQueryCacheRegion(String k{pn~)xg
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queryCacheRegion){ %{^kmlO
this.queryCacheRegion = ? p^ ':@=
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queryCacheRegion; v*EErQML8b
} _@ @"'
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publicvoid save(finalObject entity){ Fj0h-7L
getHibernateTemplate().save(entity); }}~ t!/x
} z;[Z'_B
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publicvoid persist(finalObject entity){ SLI358]$<
getHibernateTemplate().save(entity); e+P|PW
} [LHfH3[gU
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publicvoid update(finalObject entity){ 9/LJtM
getHibernateTemplate().update(entity); g;<_GL
} ut;KphvSH
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publicvoid delete(finalObject entity){ X.<2]V7!
getHibernateTemplate().delete(entity); ' $X}' u
} @)m+b;
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publicObject load(finalClass entity, )z2hyGX
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finalSerializable id){ ~CL^%\K
return getHibernateTemplate().load 1dX)l
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(entity, id); z}*74lhF
} ;/<J.
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publicObject get(finalClass entity, ShRkL<
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finalSerializable id){ pM7xnL4
return getHibernateTemplate().get jRzQ`*KC#
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(entity, id); OgBZoTT
} E[E[Za^Y
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publicList findAll(finalClass entity){ 'aW<C>
return getHibernateTemplate().find("from p3(&9~s
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" + entity.getName()); z hFk84
} BFyVq
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publicList findByNamedQuery(finalString YC0FXN V
} ~#^FFe
namedQuery){ ;R.l?Bg
return getHibernateTemplate 2d Px s:8&
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().findByNamedQuery(namedQuery); !t92_y3
} bAqaf#}e
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publicList findByNamedQuery(finalString query, l<#*[TJ
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finalObject parameter){ 1u0NG)*f
return getHibernateTemplate ,zY!EHpx
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().findByNamedQuery(query, parameter); &MsBcP[
} SZQ4e
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publicList findByNamedQuery(finalString query, /IN/SZx
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finalObject[] parameters){ =!%+ sem
return getHibernateTemplate oZ(T`5
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().findByNamedQuery(query, parameters); 'F@#.Op`
} ]1<O [d
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publicList find(finalString query){ +k4SN
return getHibernateTemplate().find h&6v&%S/L
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(query); zWh[U'6
} ]o]*&[C
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publicList find(finalString query, finalObject X%._:st
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parameter){ yy6?16@
return getHibernateTemplate().find
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(query, parameter); 2!35Tj"RFE
} $xf{m9 8
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public PaginationSupport findPageByCriteria Z{ A)
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(final DetachedCriteria detachedCriteria){ G:2m)0bW
return findPageByCriteria ;9hi2_luV
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); -a[]#v9
} v*7lJNN.
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public PaginationSupport findPageByCriteria eY1$smh t
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(final DetachedCriteria detachedCriteria, finalint n8 eR?'4
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startIndex){ +)Pv6Zog[
return findPageByCriteria /i]!=~\qFs
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(detachedCriteria, PaginationSupport.PAGESIZE, *$Df)iI6
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startIndex); AqKl}8
} q1Si*?2W
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public PaginationSupport findPageByCriteria MhNDf[W>
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(final DetachedCriteria detachedCriteria, finalint jy] hP?QG
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pageSize, F-)lRGw
finalint startIndex){ zOpl#%"
return(PaginationSupport) L$GhM!c
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getHibernateTemplate().execute(new HibernateCallback(){ uLsGb=m%b
publicObject doInHibernate >Udb*76
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(Session session)throws HibernateException { {Tp0#fi
Criteria criteria = DG x9 \8^
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detachedCriteria.getExecutableCriteria(session); n7"e 79
int totalCount = 6ZBg/_m
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((Integer) criteria.setProjection(Projections.rowCount fa#]G^f
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()).uniqueResult()).intValue(); eiJO;%fl>l
criteria.setProjection -}m#uUqI
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(null); p1Q[c0NMK
List items = nBd!296
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criteria.setFirstResult(startIndex).setMaxResults X3DXEeBEL
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(pageSize).list(); ?gb"S,
PaginationSupport ps = _=1SR\
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new PaginationSupport(items, totalCount, pageSize, .#uRJo%8
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startIndex); oAX -Sg-/$
return ps;
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} #dDsI]E)
}, true); *hAeA+:
} GqI^$5?
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public List findAllByCriteria(final ,@=qaU
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DetachedCriteria detachedCriteria){ w~EXO;L2
return(List) getHibernateTemplate \^kyC1
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().execute(new HibernateCallback(){ aW7{T6.,
publicObject doInHibernate (}fbs/8\p
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(Session session)throws HibernateException { #D3e\(
Criteria criteria = Hw5\~!FX
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detachedCriteria.getExecutableCriteria(session); />XfK,c-
return criteria.list(); Z&=K+P
} BBw`8!
}, true); L`YnrDZK
} =iRi9r'l
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public int getCountByCriteria(final EH"iK2n\9
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DetachedCriteria detachedCriteria){ #lQbMuR
Integer count = (Integer) xTX\%s|
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getHibernateTemplate().execute(new HibernateCallback(){ l/yLSGjM
publicObject doInHibernate EA2BN}
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(Session session)throws HibernateException { rd\mFz-SB
Criteria criteria = [] 0`>rVq
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detachedCriteria.getExecutableCriteria(session); 2](R}
return !&TbE@Xk
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criteria.setProjection(Projections.rowCount 4hztYOhJ{
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()).uniqueResult(); R! ?8F4G
} 0\wMlV`F
}, true); kf0zL3|
return count.intValue(); VG+Yhm<SL
} B8 -/C\
} V;?_l?_
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用户在web层构造查询条件detachedCriteria,和可选的 <"/Y`/
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 %p"x|e
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PaginationSupport的实例ps。 SxC$EQgL
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ps.getItems()得到已分页好的结果集 q^Lj)zmnK
ps.getIndexes()得到分页索引的数组 ^o"9f1s 5
ps.getTotalCount()得到总结果数 P6S^wjk
ps.getStartIndex()当前分页索引 <(?ahO5
ps.getNextIndex()下一页索引 jt
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ps.getPreviousIndex()上一页索引 <8!mmOK1
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 >Fz_]z
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 B8Jev\_
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一下代码重构了。 Iqe4O~)
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我把原本我的做法也提供出来供大家讨论吧: ;e()|
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首先,为了实现分页查询,我封装了一个Page类: y ']>J+b0
java代码: H0
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/*Created on 2005-4-14*/ Vfp{7I$#6"
package org.flyware.util.page; u7fae$:&