Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 |X{j^JP5
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 `n,RC2yo
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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 &. _"rhz
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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 /
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分页支持类: /'oo;e
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java代码: xkf2;
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package com.javaeye.common.util; }^I36$\
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import java.util.List; 548L^"D
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publicclass PaginationSupport { 6[t(FcS
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publicfinalstaticint PAGESIZE = 30; p` ~=v4;b
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privateint pageSize = PAGESIZE; 7OLHY t9
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privateList items; 5_A*IC]
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privateint totalCount; ~!ei]UP
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privateint[] indexes = newint[0]; x7B;\D#`i/
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privateint startIndex = 0; cZ%tJ(&\7X
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public PaginationSupport(List items, int ;/NC[:'$D
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totalCount){ I_#5gq
setPageSize(PAGESIZE); xd `MEOY
setTotalCount(totalCount); 3'p1m`8
setItems(items); 3LyNi$`f
setStartIndex(0); t=eI*M+>h
} UZsvYy?
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public PaginationSupport(List items, int 7r:&%?2:g
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totalCount, int startIndex){ BN(=LQ2["
setPageSize(PAGESIZE); 1z|bQ,5
setTotalCount(totalCount); xA^E+f:W_
setItems(items); lpPPI+|4N
setStartIndex(startIndex); '<,Dz=
} X<_HQ
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public PaginationSupport(List items, int Qu<6X@+5
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totalCount, int pageSize, int startIndex){ X}G$ON
setPageSize(pageSize); m{$+
setTotalCount(totalCount); v`L]dY4,
setItems(items); M8:i ]
setStartIndex(startIndex); D,*|:i
} [$K8y&\L
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publicList getItems(){ h#Rza-?"\
return items; hrJ(] [8
} Yt =)=n
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publicvoid setItems(List items){ ObZhQ.&
this.items = items; RFsUb:%V7-
} x?A<X2
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publicint getPageSize(){ | )
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return pageSize; 7L:Eg
} ,_$J-F?
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publicvoid setPageSize(int pageSize){ WnGi;AGH=1
this.pageSize = pageSize; ~u!V_su]GY
} #oiU|>3Y
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publicint getTotalCount(){ 9:g]DIL
return totalCount; ho6hjhS|u
} QSzht$8
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publicvoid setTotalCount(int totalCount){ gP|-A`y
if(totalCount > 0){ ,gpEXUp\
this.totalCount = totalCount; ;`xCfOY(
int count = totalCount / e[Vk+Te7
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pageSize; 4V{&[ Z
if(totalCount % pageSize > 0) "{+2Q
count++; y(iq
indexes = newint[count]; ->OVNmCB`+
for(int i = 0; i < count; i++){ nT01B1/<]
indexes = pageSize * %hmRh~/&
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} og8hc~:ro
}else{ I*N v|HST
this.totalCount = 0; f
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} K@:omT
} .*`]x
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publicint[] getIndexes(){ <7)sS<I
return indexes; H}_R `S
} [%yj'
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publicvoid setIndexes(int[] indexes){ 6DU(KYN
this.indexes = indexes; %=*|:v
} 4P5^.\.
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publicint getStartIndex(){ -Op^3WWyY
return startIndex; jPo,mz&^
} zp:QcL"
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publicvoid setStartIndex(int startIndex){ _UZPQ[
if(totalCount <= 0) N)D+FV29y
this.startIndex = 0; ckV\f({
elseif(startIndex >= totalCount) KkTE -$-
this.startIndex = indexes T(Yp90'6
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[indexes.length - 1]; Vg,nNa3
elseif(startIndex < 0) \K"7U
this.startIndex = 0; ZDL1H3;R
else{ +w.$"dF!
this.startIndex = indexes XUVj<U
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[startIndex / pageSize]; S"?fa)~
} N<b2xT
} IUEpE9_
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publicint getNextIndex(){ _OjZ>j<B.
int nextIndex = getStartIndex() + .Mb0++% W
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pageSize; F7j/Zuj
if(nextIndex >= totalCount) tw.GBR
return getStartIndex(); *aS+XnT/
else jTg~]PQ^
return nextIndex; 5_](N$$
} d^M*%a z
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publicint getPreviousIndex(){ "P|n'Mx
int previousIndex = getStartIndex() - WvArppANo
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pageSize; ~4=*kJ#7
if(previousIndex < 0) RR:%"4M
return0; mj9sX^$dE
else XC;Icr)
return previousIndex; gjz-CY.hz
} AWMJ/E*T
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} ?ZGsh7<k
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抽象业务类 +C~d;p
java代码: (p12=EB<
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/** g=t7YQq_~
* Created on 2005-7-12 ^dk$6%0
*/ u_+iH$zA
package com.javaeye.common.business; u;t~
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import java.io.Serializable; ,m]5j_< }
import java.util.List; Bf#cBI
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import org.hibernate.Criteria; ^Y+C!I
import org.hibernate.HibernateException; *{+{h;p
import org.hibernate.Session; eBxm
import org.hibernate.criterion.DetachedCriteria; E X'PRNB,
import org.hibernate.criterion.Projections; a9p:k
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org.springframework.orm.hibernate3.HibernateCallback; qF`6l(
import YI7M%B9Lj
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org.springframework.orm.hibernate3.support.HibernateDaoS ti%RE:*
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import com.javaeye.common.util.PaginationSupport; ^Z;zA@[wt
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public abstract class AbstractManager extends QM3DB
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HibernateDaoSupport { Y2 J-`o$5
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privateboolean cacheQueries = false; jy2gR1~
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privateString queryCacheRegion; /; Bmh=
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publicvoid setCacheQueries(boolean .S-)
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cacheQueries){ EmcLW74
this.cacheQueries = cacheQueries; !YjxCx
} 7CuZ7!>$
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publicvoid setQueryCacheRegion(String f4Y)GO<R]
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queryCacheRegion){ V+lF|CZb5
this.queryCacheRegion = lD3nz<p
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queryCacheRegion; :p: C
} {LF4_9 =
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publicvoid save(finalObject entity){ ]r|oNGD)G
getHibernateTemplate().save(entity); :[_msd
} 1
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publicvoid persist(finalObject entity){ q{Z#}|km#
getHibernateTemplate().save(entity); m?<E >-bI
} ~o%igJ
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publicvoid update(finalObject entity){ HVHv,:bPo
getHibernateTemplate().update(entity); qJdlZW<
} )'U0n`=
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publicvoid delete(finalObject entity){ ]1<GZ`
getHibernateTemplate().delete(entity); 9/(jY$Ar
} 18Y#=uH}
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publicObject load(finalClass entity, pCh v;
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finalSerializable id){ s b;q)Rh
return getHibernateTemplate().load \$wkr
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(entity, id); :NF4[c
} ,?|$D Y+=
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publicObject get(finalClass entity, WrGnLE
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finalSerializable id){ \\FT.e6
return getHibernateTemplate().get .N
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(entity, id); =otO@22Np
} , [|aWT%9
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publicList findAll(finalClass entity){ -U=Ci
return getHibernateTemplate().find("from a9.yuSzL
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" + entity.getName()); A<X?1$
} O9sEaVX
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publicList findByNamedQuery(finalString Q# B0JT1
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namedQuery){ \c:$eF
return getHibernateTemplate '*b]$5*p
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().findByNamedQuery(namedQuery); VIT|#
} y'K2#Y~1e
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publicList findByNamedQuery(finalString query, pZ.b
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finalObject parameter){ \x}\)m_7M<
return getHibernateTemplate IA@>'O
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().findByNamedQuery(query, parameter); aaR& -M@
} ;XurH%Mg
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publicList findByNamedQuery(finalString query, hF,|()E[
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finalObject[] parameters){ XVN`J]XHk
return getHibernateTemplate U-I,Q+[C[^
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().findByNamedQuery(query, parameters); 3=YpZ\l}
} __g
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publicList find(finalString query){ 4#B'pJMw9
return getHibernateTemplate().find Y &Cb
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(query); zsg\|=P
} OM*c7&
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publicList find(finalString query, finalObject %y6(+I#P
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parameter){ _p-e)J$7
return getHibernateTemplate().find &J>e;X
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(query, parameter); t*gZcw5 r
} {]T?) !Vm
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public PaginationSupport findPageByCriteria UTD_rQ
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(final DetachedCriteria detachedCriteria){ X7},|cmD_
return findPageByCriteria y|5L%,i
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(detachedCriteria, PaginationSupport.PAGESIZE, 0);
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} ]M7FIDg
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public PaginationSupport findPageByCriteria IfK~~XYG
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(final DetachedCriteria detachedCriteria, finalint Y[{:?i~9,
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startIndex){ 9TW[;P2> )
return findPageByCriteria D'g,<-ahl
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(detachedCriteria, PaginationSupport.PAGESIZE, ?=? _32O
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startIndex); 6 c_#"4
} -s3`mc}*
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public PaginationSupport findPageByCriteria 4&}%GH>}
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(final DetachedCriteria detachedCriteria, finalint kxMvOB$
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pageSize, *N">93:
finalint startIndex){ =;rLv7(a
return(PaginationSupport) SqM>xm
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getHibernateTemplate().execute(new HibernateCallback(){ h?mDtMCw2
publicObject doInHibernate S,m(
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(Session session)throws HibernateException { +A|
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Criteria criteria = 2S?7j[@%i`
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detachedCriteria.getExecutableCriteria(session); }[AaI #
int totalCount = u<-)C)z
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((Integer) criteria.setProjection(Projections.rowCount 0#*6:{/^
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()).uniqueResult()).intValue(); !HY^QK
criteria.setProjection u]yy%@U1
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(null); $*#a;w7\C
List items = %HUex
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criteria.setFirstResult(startIndex).setMaxResults m'rDoly"62
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(pageSize).list(); J @Hg7Faz
PaginationSupport ps = |[SHpcq>
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new PaginationSupport(items, totalCount, pageSize, ]o6ZZK
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startIndex); 1}(22Q;
return ps; TeHJj`rdAU
} O~3
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}, true); u{sHuVl
} L;Ff(0x|
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public List findAllByCriteria(final :zY4phR
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DetachedCriteria detachedCriteria){ 4V@%Y,:ee
return(List) getHibernateTemplate Q:A#4Z
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().execute(new HibernateCallback(){ HpnF,4A>
publicObject doInHibernate )w7vE\n3
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(Session session)throws HibernateException { ,lZ19B?WP
Criteria criteria = eh86-tQI~(
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detachedCriteria.getExecutableCriteria(session); ,'8%'xit
return criteria.list(); roADC?@r
} tFmB`*!%
}, true); 6,>$Jzs)5E
} K*~{M+lU7
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public int getCountByCriteria(final w1/QnV
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DetachedCriteria detachedCriteria){ _{[6hf4p
Integer count = (Integer) 6}"%>9
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getHibernateTemplate().execute(new HibernateCallback(){ htBA.eQ
publicObject doInHibernate dyQ7@K.E
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(Session session)throws HibernateException { G6G Bqp6|
Criteria criteria = %e
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detachedCriteria.getExecutableCriteria(session); "Z.6@
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return p{Lrv%-j
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criteria.setProjection(Projections.rowCount ]A5F}wV4
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()).uniqueResult(); =pL$*`]?
} Nq8ON!<<
}, true); (TZK~+]@sb
return count.intValue(); "qmSwdM
} zL"e .
} 4.O) /0sU
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用户在web层构造查询条件detachedCriteria,和可选的 8zK#./0\
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 Z(MZbzY7Hq
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PaginationSupport的实例ps。 @Jd&[T27Lr
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ps.getItems()得到已分页好的结果集 T`#nn|
ps.getIndexes()得到分页索引的数组 yYz{*hq
ps.getTotalCount()得到总结果数 |`T7}U
ps.getStartIndex()当前分页索引 -.D?Z8e
ps.getNextIndex()下一页索引 v=k+MvX
ps.getPreviousIndex()上一页索引 i}m'#b
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 ![z2]L+TB
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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 xlv(PVdn
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一下代码重构了。 cH_qHXi[G
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我把原本我的做法也提供出来供大家讨论吧: |f_'(-v`E
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首先,为了实现分页查询,我封装了一个Page类: >Na. C(DZ
java代码: &M|rRd~*
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/*Created on 2005-4-14*/ }?2X
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package org.flyware.util.page; \(Ma>E4PNU
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/** }3lG'Y#Kpy
* @author Joa 3zsp6k V
* JD*HG]
*/ OY1bFIE
publicclass Page { @Ou
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/** imply if the page has previous page */ , Q0Y} )
privateboolean hasPrePage; ?`+VWa[,e
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/** imply if the page has next page */ :!Ci#[g
privateboolean hasNextPage; OU{c|O
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/** the number of every page */ `+w= p7ET
privateint everyPage; P00G*iY~\
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/** the total page number */ ,7V?Kj
privateint totalPage; SPqJ
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/** the number of current page */ 3eY>LWx
privateint currentPage; 'xS@cFo(
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/** the begin index of the records by the current nmpc<&<<
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query */ #M!u';bZ
privateint beginIndex; %oiF} >
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/** The default constructor */ )f3A\^
public Page(){ >vD}gGBe
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} x<I[?GT=
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/** construct the page by everyPage G$,s.MSf
* @param everyPage ZV{C9S&
* */ C]b:#S ${
public Page(int everyPage){ du$lS':`
this.everyPage = everyPage; 7 7bwYKIn
} 2S_u/32]W
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/** The whole constructor */ 4D&