Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 ]xq::a{Oy
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 G:+16XCra
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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 )bW5yG!
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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 ]t/f<jKN^
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分页支持类: }K8Lm-.=
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java代码: R#0{Wg0O)
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package com.javaeye.common.util; aW`dFitpM
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import java.util.List; [-VGArD[k,
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publicclass PaginationSupport { E/"SU*Co
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publicfinalstaticint PAGESIZE = 30; ;QidDi_s>
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privateint pageSize = PAGESIZE; v' 0!= r
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privateList items; uYTCd ZQh
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privateint totalCount; I<`V_
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privateint[] indexes = newint[0]; v |ifI
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privateint startIndex = 0; u{+!&
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public PaginationSupport(List items, int t&f" jPu>
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totalCount){ Q [:<S/w
setPageSize(PAGESIZE); R9=K(pOT
setTotalCount(totalCount); e`ex]py<C
setItems(items); E._hg+
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setStartIndex(0); .Cfp'u%\;
} #11RLvDQd
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public PaginationSupport(List items, int k#jm7 +
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totalCount, int startIndex){ L<E/,IdE
setPageSize(PAGESIZE); poY8
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setTotalCount(totalCount); `$Kes;[X
setItems(items); _FFv#R*4
setStartIndex(startIndex); -$ali[
} qvN"1=nJ
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public PaginationSupport(List items, int Bt6xV<jD
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totalCount, int pageSize, int startIndex){ 0x4l5x$8
setPageSize(pageSize); ~ a>S#S
setTotalCount(totalCount); dgY5ccP
setItems(items); ecT]p
setStartIndex(startIndex); "s;ci~$
} }#|2z}!
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publicList getItems(){ z"3H{ A
return items; .)0gz!Z
} w<mqe0
* 2%oZXF
publicvoid setItems(List items){ fr]Hc+7
this.items = items; n531rkK-
} P|v ?
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publicint getPageSize(){ iW-t}}Z>B
return pageSize; Y)v%
} Hq-v@@0 *
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publicvoid setPageSize(int pageSize){ hvL6zCi
this.pageSize = pageSize; `{WCrw6)
} 1V\1]J/
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publicint getTotalCount(){ {~"Em'}J
return totalCount; YiO3<}Uf
} ZgK@Fl*k
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publicvoid setTotalCount(int totalCount){ G-sa
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if(totalCount > 0){ cY^Y!.,
this.totalCount = totalCount; %WmZ ]@M
int count = totalCount / s1v{~xP
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pageSize; <@%ma2
if(totalCount % pageSize > 0) 8m \;P
count++; wV?[3bEhM
indexes = newint[count]; E8
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for(int i = 0; i < count; i++){ wb@]>MJ}[s
indexes = pageSize * 6XZN>#
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} r*>QT:sB
}else{ iAg}pwU
this.totalCount = 0; NrW [Q3E$
} =$[W,+X6f
} cUYX1a)8
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publicint[] getIndexes(){ pM,#wYL
return indexes; zcZ^s v>
} z{AM2Z
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publicvoid setIndexes(int[] indexes){ jw/wcP
this.indexes = indexes; QZz&1n
} nWd:>Ur
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publicint getStartIndex(){ miWw6!()
return startIndex; f)qPFM]%z
} ^1()W,B~w
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publicvoid setStartIndex(int startIndex){ P%ye$SASd
if(totalCount <= 0) *pY/5? g
this.startIndex = 0; La@\q[U{@
elseif(startIndex >= totalCount) eO~eu]r
this.startIndex = indexes D_zcOq9
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[indexes.length - 1]; Y{`3`Pg&N
elseif(startIndex < 0) qNhH%tYQ
this.startIndex = 0; D~XU`;~u
else{ 7Z9.z4\
this.startIndex = indexes "hJ7 Vv_
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[startIndex / pageSize]; |yuGK
} V#+126
} Z^6A_:]j
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publicint getNextIndex(){ oA5<[&~<
int nextIndex = getStartIndex() + A3m{jbh
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pageSize; 8|fLe\"
if(nextIndex >= totalCount) D<lQoO+
return getStartIndex(); Cln^ 1N0
else NU BpIx&
return nextIndex; 5+o
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} VZAuUw+M
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publicint getPreviousIndex(){ hqdC9?\
int previousIndex = getStartIndex() - `8.1&fBr
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pageSize; F0X5dv
if(previousIndex < 0) "v*oga%
return0; Cij$GYkv
else >aNbp
return previousIndex; B:B0p+$I
} nD^{Q[E6=
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} JI28O8
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抽象业务类 IptB.bYc
java代码: 7Y$4MMNQ
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/** liBAJx
* Created on 2005-7-12 "H
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*/ BT
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package com.javaeye.common.business; #RCZA4>
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import java.io.Serializable; Nv}U/$$S
import java.util.List; tg4LE?nv
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import org.hibernate.Criteria; t?pIE cl
import org.hibernate.HibernateException; B<vvsp\X
import org.hibernate.Session; !Qj)tS#Az
import org.hibernate.criterion.DetachedCriteria; OqAh4qa,$
import org.hibernate.criterion.Projections; m70`{-O
import
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org.springframework.orm.hibernate3.HibernateCallback; 5i}CzA96
import cKvAR5|
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org.springframework.orm.hibernate3.support.HibernateDaoS r{;VTQ
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upport; uD0(aqAZ
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import com.javaeye.common.util.PaginationSupport; x9FLr}e
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public abstract class AbstractManager extends E7d~#
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HibernateDaoSupport { M6o
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privateboolean cacheQueries = false; C}M0XW
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privateString queryCacheRegion; (r#5O9|S
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publicvoid setCacheQueries(boolean r_!{!i3B
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cacheQueries){ I{*.htt{
this.cacheQueries = cacheQueries; tkm~KLWV&7
} |IyM"UH
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publicvoid setQueryCacheRegion(String vu
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queryCacheRegion){ /h}wM6pg
this.queryCacheRegion = , u8ZS|9
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queryCacheRegion; t(uB66(_F
} S20 nk.x
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publicvoid save(finalObject entity){ YG}p$\R
getHibernateTemplate().save(entity); 14@q $}sf
} DRKc&F6Qy
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publicvoid persist(finalObject entity){ o}r!qL0c
getHibernateTemplate().save(entity); )n[`Z#
} ;Wfv+]n9
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publicvoid update(finalObject entity){ vJ# rW8y
getHibernateTemplate().update(entity); !"o1ve`{
} N>F2
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publicvoid delete(finalObject entity){ kG|>_5
getHibernateTemplate().delete(entity); )|59FOWg
} dcrJ,>i}
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publicObject load(finalClass entity, b}EYNCw_7S
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finalSerializable id){ Kc-A-P &Ry
return getHibernateTemplate().load o%N0K
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(entity, id); R"8})a
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} ^,ZvKA"}+/
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publicObject get(finalClass entity, @'NaA SB
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finalSerializable id){ <Vr]2mw
return getHibernateTemplate().get lhIr]'?l
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(entity, id); pO 7{3%
} 4/mj"PBKL
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publicList findAll(finalClass entity){ F_M~!]<na
return getHibernateTemplate().find("from Xx9~
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" + entity.getName()); +^]PBMM1w
} T^=Ee?e
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publicList findByNamedQuery(finalString ~;O=
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namedQuery){ DY+8m8!4H
return getHibernateTemplate e)
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().findByNamedQuery(namedQuery); !!D:V`F/d
} ytBxe]
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publicList findByNamedQuery(finalString query, tKqCy\-q
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finalObject parameter){ vI:bl~
return getHibernateTemplate E#HU?<q8
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().findByNamedQuery(query, parameter); }mT%N eS
} :BZx)HxQ
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publicList findByNamedQuery(finalString query, (1r>50Ge
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finalObject[] parameters){ * v7& T
return getHibernateTemplate zf!\wY"`
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().findByNamedQuery(query, parameters); WY.\<$7
} OD@@O9
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publicList find(finalString query){ nD?M;XN
return getHibernateTemplate().find $0`$)(Y
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(query); /xm} ?t0U
} k
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publicList find(finalString query, finalObject G~$M"@Q7N
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parameter){ 1-Wnc'(OK
return getHibernateTemplate().find DGuUI}|)
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(query, parameter); 51(`wo>LS
} 5)zh@aJ@
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public PaginationSupport findPageByCriteria |EEz>ci
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(final DetachedCriteria detachedCriteria){ '>WuukC
return findPageByCriteria YvP"W/5
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); .Mft+,"
} `\u),$
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public PaginationSupport findPageByCriteria z1KC$~{O
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(final DetachedCriteria detachedCriteria, finalint z?) RF[
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startIndex){ Kd[`mkmS
return findPageByCriteria 63dtO{:4
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(detachedCriteria, PaginationSupport.PAGESIZE, G|Yp<W%o
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startIndex); ~aq?Kk
} 2] wf`9ZH
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public PaginationSupport findPageByCriteria `::(jW.KO
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(final DetachedCriteria detachedCriteria, finalint "E[*rnsLN
n YMf[kW
pageSize, ZzaW@6LJF
finalint startIndex){ ' ^L
return(PaginationSupport) hw.demD
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getHibernateTemplate().execute(new HibernateCallback(){ ;NVTn<Uj
publicObject doInHibernate wTAEJ{p
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(Session session)throws HibernateException { Q\>SF
Criteria criteria = cW|Zgz8vv
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detachedCriteria.getExecutableCriteria(session); lJQl$Wx^
int totalCount = 7)It1i-
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((Integer) criteria.setProjection(Projections.rowCount 28qWC~/9
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()).uniqueResult()).intValue(); DdZ_2B2
criteria.setProjection `YU:kj<6
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(null); i2R]lE8
List items = UU~;B
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criteria.setFirstResult(startIndex).setMaxResults cw-JGqLx
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(pageSize).list(); KdQ|$t
PaginationSupport ps = *wZV*)}
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new PaginationSupport(items, totalCount, pageSize, ?@BaBU:o`F
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startIndex); ]qG5Ne_
return ps; vh3iu+
} <yaw9k+P
}, true); IG@&l0ARL
} 0_Z|y/I.
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public List findAllByCriteria(final I8wVvs;k
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DetachedCriteria detachedCriteria){ ^9~%=k=
return(List) getHibernateTemplate @9P9U`ZP
)s[S.`STz
().execute(new HibernateCallback(){ ]Lft^,7
publicObject doInHibernate y/*Tvb #TJ
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(Session session)throws HibernateException { T7nX8{l[RG
Criteria criteria = u\Q**m2XP
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detachedCriteria.getExecutableCriteria(session); bH]!~[
return criteria.list(); (j
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} o:\j/+]
}, true); `D4'`Or-U
} mP+yjRw
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public int getCountByCriteria(final *wyLX9{:
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DetachedCriteria detachedCriteria){ 0s[3:bZ\Ia
Integer count = (Integer) qCT\rZU
_( /lBf{|
getHibernateTemplate().execute(new HibernateCallback(){ gxtbu$
publicObject doInHibernate tdK^X1
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(Session session)throws HibernateException { 2G>
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Criteria criteria = xJ5!`#=
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detachedCriteria.getExecutableCriteria(session); 4^9_E&Fa
return yp'>+cLa
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criteria.setProjection(Projections.rowCount l+qtA~V&2
<T[ui
()).uniqueResult(); epyYo&x}
} m)w-mc
}, true); -\v8i.w0
return count.intValue(); 3`8xh9O
} $ !=:ES
} t O;W?g
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用户在web层构造查询条件detachedCriteria,和可选的 7OHw/-j\
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 =x]dP.
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PaginationSupport的实例ps。 1D DOUV
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ps.getItems()得到已分页好的结果集 cYS+XBz
ps.getIndexes()得到分页索引的数组 > PA,72e
ps.getTotalCount()得到总结果数 6VE5C
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ps.getStartIndex()当前分页索引 h(up1(x
ps.getNextIndex()下一页索引 >?FCv7qN
ps.getPreviousIndex()上一页索引 8 z7,W3b
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 >xgd<
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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 z*1K<w8
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一下代码重构了。 f/m6q8!L{
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我把原本我的做法也提供出来供大家讨论吧: F'*4:WD7
- mXr6R?
首先,为了实现分页查询,我封装了一个Page类: {mGWMv
java代码: n/D]r
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/*Created on 2005-4-14*/ NQ=YTRU
package org.flyware.util.page; NDGBvb
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/** +2O_LPV$,
* @author Joa 4N:
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* ??Ac=K\
*/ 1^dWmxUZH
publicclass Page { Z8UM0B=i
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/** imply if the page has previous page */ Wno5B/V
privateboolean hasPrePage; t,nB`g?
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/** imply if the page has next page */ gvYs<,:
privateboolean hasNextPage; B[50{;X
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/** the number of every page */ d5hE!=
privateint everyPage; m"]ys#
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v
/** the total page number */ ~V)E:(
privateint totalPage; ;_\P;s
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/** the number of current page */ #CmBgxg+M
privateint currentPage; pT tX[CE
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/** the begin index of the records by the current c-d}E!C:
@Iu-F4YT
query */ l-EQh*!j
privateint beginIndex; T(F8z5s5
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/** The default constructor */ oJ:J'$W(
public Page(){ AF6'JxG7
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} H=C;g)R
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/** construct the page by everyPage Pa<