Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 8i pez/
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 +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 cNH7C"@GVu
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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 y)*RV;^
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分页支持类: N;gfbh]
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java代码: He)%S]RLk
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package com.javaeye.common.util; 6nQq
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import java.util.List; CWlw0X
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publicclass PaginationSupport { iB{V^ksU
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publicfinalstaticint PAGESIZE = 30; ,s(,S
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privateint pageSize = PAGESIZE; 4z? l
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privateList items; SdWV3
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privateint totalCount; 40/Y\
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privateint[] indexes = newint[0]; :>*7=q=
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privateint startIndex = 0; (?c-iKGc
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public PaginationSupport(List items, int 99S^f:t
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totalCount){ :
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setPageSize(PAGESIZE); T|p"0b A
setTotalCount(totalCount); ~`/V(r;o
setItems(items); xmX 4qtAL
setStartIndex(0); g*Phv|kI
} g{Rd=1SK]
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public PaginationSupport(List items, int g :OI
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totalCount, int startIndex){ s S
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setPageSize(PAGESIZE); ?(PKeq6
setTotalCount(totalCount); 9z0p5)]n>
setItems(items); j [a(#V{
setStartIndex(startIndex); /mHqurB
} "8/,Y"W"
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public PaginationSupport(List items, int Bwrx *J
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totalCount, int pageSize, int startIndex){ CAe!7HiR
setPageSize(pageSize); j+!v}*I![
setTotalCount(totalCount); h 0|s
setItems(items); N;R^h? '
setStartIndex(startIndex); @L`jk+Y0vF
} *R"/ |Ka
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publicList getItems(){ H::bwn`Vc
return items; \^LFkp
} B:<VA=
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publicvoid setItems(List items){ ~rm_vo
this.items = items; t7pFW^&
} /}$+uBgJm
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publicint getPageSize(){ IgzQr >
return pageSize; FwK]$4*
} Om<a<q
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publicvoid setPageSize(int pageSize){ >!JS:5|
this.pageSize = pageSize; N[hG8f
} IBGrt^$M
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publicint getTotalCount(){ +_!QSU,@
return totalCount; _{>vTBU4F
} }vuARZ>
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publicvoid setTotalCount(int totalCount){ B?QIN]
if(totalCount > 0){ b>W%t
this.totalCount = totalCount; mDWG7 Asp
int count = totalCount / "Q<MS'a
# _1`)VS
pageSize; [^)g%|W
if(totalCount % pageSize > 0) 0K+ne0I
count++; baasGa3}s
indexes = newint[count]; GdwVtqbX
for(int i = 0; i < count; i++){ gR**@t=;j
indexes = pageSize * .`lCWeHN
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} ?[AD=rUC
}else{ /z!%d%"
this.totalCount = 0; ]]mJ']l
} w
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} ,}PgOJZ
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publicint[] getIndexes(){ _#niyW+?~
return indexes; 0f/<7R
} )4OxY[2J
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publicvoid setIndexes(int[] indexes){ m*pJBZxd
this.indexes = indexes; ]lbuy7xj63
} xAr\gu
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publicint getStartIndex(){ F847pyOJnf
return startIndex; M7T5
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} XUYtEf
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publicvoid setStartIndex(int startIndex){ pb}*\/s
if(totalCount <= 0) *g%yRU{N
this.startIndex = 0; +R &gqja
elseif(startIndex >= totalCount) WLT"ji0w2
this.startIndex = indexes vgPCQO([
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[indexes.length - 1]; }j%5t ~Qa
elseif(startIndex < 0) j_AACq
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this.startIndex = 0; +rd+0 `}C
else{ 3n _htgcv
this.startIndex = indexes <YY 14p
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[startIndex / pageSize]; QV!up^Zso
} CrLrw T
} }tz7b#
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publicint getNextIndex(){ ;I}fBZ3
int nextIndex = getStartIndex() + l**X^+=$
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pageSize; )e{aN+
if(nextIndex >= totalCount) (zk"~Ud
return getStartIndex(); qm}@!z^
else {FkF
return nextIndex; .nJz G
} s<Ziegmw|g
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publicint getPreviousIndex(){ jp,4h4C^)
int previousIndex = getStartIndex() - R_C)
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pageSize; dN q$}
if(previousIndex < 0) F8=+j_UGI
return0; L0,'mS
else vP&(-a
return previousIndex; S[gx{Bxiw
} <I?Zk80
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} :;}P*T*PU
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抽象业务类 fhiM U8(&
java代码: ?,mmYW6TjB
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/** /v{I
* Created on 2005-7-12 [0!( xp^
*/ t Q)qCk07
package com.javaeye.common.business; D*jM1w_`
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import java.io.Serializable; (.:e,l{U%
import java.util.List; p K*TE5]
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import org.hibernate.Criteria; <'u'#E@"sl
import org.hibernate.HibernateException; ?<!|
import org.hibernate.Session; )lkjqFQ(
import org.hibernate.criterion.DetachedCriteria; * 4'"2"
import org.hibernate.criterion.Projections; 2y4bwi
import V3Bz
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org.springframework.orm.hibernate3.HibernateCallback; &C}*w2]0S
import U^PgG|0N
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org.springframework.orm.hibernate3.support.HibernateDaoS =X}J6|>X
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upport; $xsd~L&
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import com.javaeye.common.util.PaginationSupport; 43cE`9~
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public abstract class AbstractManager extends >*bvw~y,
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HibernateDaoSupport { ]Ljf?tk
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privateboolean cacheQueries = false; q.vIc
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privateString queryCacheRegion; PT
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publicvoid setCacheQueries(boolean bA 2pbjg=
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cacheQueries){ /
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this.cacheQueries = cacheQueries; x`s>*^
} SbZ6t$"
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publicvoid setQueryCacheRegion(String z:O8Ls^\T
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queryCacheRegion){ "@kaHIf[
this.queryCacheRegion = %<5'=t'|-U
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queryCacheRegion; kfNWI#'9
} !>tL6+yj
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publicvoid save(finalObject entity){ KoY F]
getHibernateTemplate().save(entity); }]TxlSp!;
} /reX{Y
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publicvoid persist(finalObject entity){ hZ3bVi)L\
getHibernateTemplate().save(entity); iLT}oKF2N;
} 9uY'E'm*
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publicvoid update(finalObject entity){
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getHibernateTemplate().update(entity); J4utIGF
} 0x7'^Z>-oe
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publicvoid delete(finalObject entity){ <i[HbgUlO.
getHibernateTemplate().delete(entity); ^aQ"E9
} ivPg9J1S
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publicObject load(finalClass entity, Bx!-"e
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finalSerializable id){ ;jPXs
return getHibernateTemplate().load -M2yw
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(entity, id); @;kSx":b
} H]!"Zq k
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publicObject get(finalClass entity, >7r!~+B"9'
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finalSerializable id){ x"(KBEK~
return getHibernateTemplate().get %SI'BJ
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(entity, id); "3hMq1NQ`g
} ] - .aL
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publicList findAll(finalClass entity){ :4s1CC+@\
return getHibernateTemplate().find("from aT<q=DO
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" + entity.getName()); q;U,s)Uz^
} J;%Xfx]
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publicList findByNamedQuery(finalString 5ZK@`jkE
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namedQuery){ q$tUH)0
return getHibernateTemplate
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().findByNamedQuery(namedQuery); DBD%6o>]K
} q~ZNd3O
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publicList findByNamedQuery(finalString query, z'\_jaj^
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finalObject parameter){ `_RTw5{
return getHibernateTemplate w6GyBo{2O_
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().findByNamedQuery(query, parameter); $?<Z!*x
} SB|Qa}62
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publicList findByNamedQuery(finalString query, khrb-IY@
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finalObject[] parameters){ l6kWQpV
return getHibernateTemplate G) 7;;
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().findByNamedQuery(query, parameters); *q".-u!D[
} @&:ar
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publicList find(finalString query){ PCM-i{6/
return getHibernateTemplate().find 9qz6]-K
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(query); #9xd[A: N
} %_L\z*+
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publicList find(finalString query, finalObject qI<mjB{3`
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parameter){ X+}1
return getHibernateTemplate().find pxf$1
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(query, parameter); #Av.iAs
} vIwCJN1C
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public PaginationSupport findPageByCriteria 9;Ox;;w
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(final DetachedCriteria detachedCriteria){ >W`4aA
return findPageByCriteria g(J&m<I
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); fCtPu08{Z
} +0q>fp_K(+
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public PaginationSupport findPageByCriteria <5jzl
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(final DetachedCriteria detachedCriteria, finalint Z%Zd2
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startIndex){ zs*L~_K
return findPageByCriteria '07P&g-
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(detachedCriteria, PaginationSupport.PAGESIZE, i21Gw41p:
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startIndex); .h5[Q/*h
} 'n$%Ls}S
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public PaginationSupport findPageByCriteria /2Bi@syxK
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(final DetachedCriteria detachedCriteria, finalint )V:]g\t
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pageSize, z,bQQ;z9
finalint startIndex){ 70mpSD3
return(PaginationSupport) !G}+E2fDA
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getHibernateTemplate().execute(new HibernateCallback(){ DHT&,=
publicObject doInHibernate ${nX:!)
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(Session session)throws HibernateException { UNi`P9D]3
Criteria criteria = GSQ/NYK
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detachedCriteria.getExecutableCriteria(session); Gkxj?)`
int totalCount = fH?ha
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((Integer) criteria.setProjection(Projections.rowCount ?8mlZ
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()).uniqueResult()).intValue(); ^T,Gu-2>
criteria.setProjection la?Wnw
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(null); i^!ez5z
List items = ?
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criteria.setFirstResult(startIndex).setMaxResults A
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(pageSize).list(); X5*C+ I=2
PaginationSupport ps = ez9k4IO
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new PaginationSupport(items, totalCount, pageSize, vkRi5!bR
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startIndex); P{lh)m>
return ps;
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} ~_}4jnC
}, true); ZW* fOaj
} _5h0@^m7y
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public List findAllByCriteria(final fm6]CU1^
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DetachedCriteria detachedCriteria){ 3*\8p6G
return(List) getHibernateTemplate w)<4>(D
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().execute(new HibernateCallback(){ Vw?P.4
publicObject doInHibernate Nz @8
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(Session session)throws HibernateException { s7Qyfe&>
Criteria criteria = J/gQQ.s
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detachedCriteria.getExecutableCriteria(session); ZE ^u .>5
return criteria.list(); eu=|t&FKk
} Fi k@hu
}, true); *p"O*zj
} Ebbe=4
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public int getCountByCriteria(final 5EfY9}dl
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DetachedCriteria detachedCriteria){ }*ODM6
Integer count = (Integer) 8ipW3~-4
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getHibernateTemplate().execute(new HibernateCallback(){ 1+FYjh!2t
publicObject doInHibernate o[2Y;kP3*P
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(Session session)throws HibernateException { 4&H+hN{3
Criteria criteria = 4Z],+?.[
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detachedCriteria.getExecutableCriteria(session); R$v i!0
return zAu}hVcW
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criteria.setProjection(Projections.rowCount NywB3
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()).uniqueResult(); [6tR&D#K
} jf2y0W>6s
}, true); IZ|c<#r6
return count.intValue(); a{5H33JA
} iczs8gj*
} ~igRg~k:/
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用户在web层构造查询条件detachedCriteria,和可选的 WvIK=fdZ$
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 _QD/!~O
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PaginationSupport的实例ps。 +'!h-x1y~
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ps.getItems()得到已分页好的结果集 #tCIuQ,
ps.getIndexes()得到分页索引的数组 B'NS&7+].
ps.getTotalCount()得到总结果数 IJ+O),'
ps.getStartIndex()当前分页索引 _a?wf!4>P
ps.getNextIndex()下一页索引 e-&L\M
ps.getPreviousIndex()上一页索引 +>n.T
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 s0x@
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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 }])GQ@
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一下代码重构了。 {X{01j};8
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我把原本我的做法也提供出来供大家讨论吧: ]9!Gg
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首先,为了实现分页查询,我封装了一个Page类: t!+%g) @
java代码: {&6l\|
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/*Created on 2005-4-14*/ }WBm%f
package org.flyware.util.page; K6PC&+x
/9t*CEu\
/** /i7>&ND.r
* @author Joa #,Fx@3y\a
* x<)!$cg
*/ )%-\hl]
publicclass Page { zmrX%!CW
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/** imply if the page has previous page */ tPMgZ
privateboolean hasPrePage; 'PxL^
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/** imply if the page has next page */ j:\_*f
privateboolean hasNextPage; kG~ivB}x
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/** the number of every page */ noD7G2o
privateint everyPage; g
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$$)<(MP3
/** the total page number */ QvyUd%e'5A
privateint totalPage; U iPVZ@?
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/** the number of current page */ hyr5D9d
privateint currentPage; jw6 ng>9
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/** the begin index of the records by the current `04Y ;@w
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query */ GO&R