Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 @-}]~|<
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 (XJQ$n
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据这一功能,我设计了通用的抽象Bean基类和分页类支持,代码来 .Dm{mV@*T
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自于Quake Wang的javaeye-core包的相应类,然后又做了很多修改 2e"}5b5
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分页支持类: `vw.~OBl
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java代码: 4lCm(#T{,
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package com.javaeye.common.util; AHGcWS\,X
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import java.util.List; 8H?AL
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publicclass PaginationSupport { _3a
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publicfinalstaticint PAGESIZE = 30; @:B1
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privateint pageSize = PAGESIZE; qgNK!(kWpr
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privateList items; [2V/v
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privateint totalCount; 0
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privateint[] indexes = newint[0]; "[yiNJ"kt
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privateint startIndex = 0; T"U t).
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public PaginationSupport(List items, int Umg81!
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totalCount){ Phu|
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setPageSize(PAGESIZE); n bk(FD6
setTotalCount(totalCount); R:?vY!
setItems(items); `x)bw
setStartIndex(0); |m- `,
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} 1#"Q' ,7
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public PaginationSupport(List items, int (+dRD]|T
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totalCount, int startIndex){ G`"Cqs<
setPageSize(PAGESIZE); <>_WdAOuD
setTotalCount(totalCount); )AXH^&
setItems(items); }3w b*,Sbz
setStartIndex(startIndex); ~b0qrjF;O
} i&)C,
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public PaginationSupport(List items, int Ir #V2]$
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totalCount, int pageSize, int startIndex){ :'~ gLW>j
setPageSize(pageSize); =fK'Ep[
setTotalCount(totalCount); om?CFl
setItems(items); yXg1N
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setStartIndex(startIndex); X:&p9_O@
} lVtn$frp
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publicList getItems(){ ]xEE7H]\h
return items; yuEOQ\!(u
} p]Zabky
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publicvoid setItems(List items){ #%b()I_([
this.items = items; XS8~jBjx
} s$x] fO
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publicint getPageSize(){ X@U1Ri
return pageSize; CL :M>(
} Ag0_^
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publicvoid setPageSize(int pageSize){ =@=R)C4f*
this.pageSize = pageSize; } <4[(N
} NqE7[wH
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publicint getTotalCount(){ NP'Ke:
return totalCount; t<,p-TM]
} g4a X
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publicvoid setTotalCount(int totalCount){ oh0|2IrM
if(totalCount > 0){ b.q"s6u
this.totalCount = totalCount; A>%UYA
int count = totalCount / +WN>9V0H
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pageSize; h!av)nhM
if(totalCount % pageSize > 0) oV>AFs6
count++; zy6(S_j
indexes = newint[count]; a<jE25t
for(int i = 0; i < count; i++){ ^@L
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indexes = pageSize * I7z/GA\x
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} &d3 '{~:
}else{ I@Z*Nu1L
this.totalCount = 0; U4l*;od
} PJ'lZu8?x
} Bi:wP/>v
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publicint[] getIndexes(){ }9udo,RWu
return indexes; 8pMZ~W;
} `W$0T;MPF
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publicvoid setIndexes(int[] indexes){ [=ak>>8
this.indexes = indexes; 'ag6B(0Z
} |z.GSI_!)
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publicint getStartIndex(){ |\n)<r_
return startIndex; 3hf;4Mb
} ro^6:w3O^
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publicvoid setStartIndex(int startIndex){ w[7.@ %^[
if(totalCount <= 0) Xe3z6
this.startIndex = 0; A='+tJa
elseif(startIndex >= totalCount) Z F yX@#B9
this.startIndex = indexes PT@e),{~o9
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[indexes.length - 1]; 4Re@ QOZ
elseif(startIndex < 0) q\'P1~
this.startIndex = 0; Jv^cOc
else{ \P~rg~
this.startIndex = indexes hf+/kc!>i
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[startIndex / pageSize]; {&}/p-S
} 4IP\iw#w
} j)tCr Py
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publicint getNextIndex(){ @S"pJeP/f
int nextIndex = getStartIndex() + {_toh/8)r
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pageSize; i=X*
if(nextIndex >= totalCount) A6UdWK
return getStartIndex(); a}qse5Fr
else M`+e'vdw
return nextIndex; !P60[*>
} _E1]cbIo
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publicint getPreviousIndex(){ E7NbPNd
int previousIndex = getStartIndex() - g t^]32$
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pageSize; $mI:Im`s
if(previousIndex < 0) ZA_zKJ[[7
return0; Y =g>r]2
else Ih-3t*L
return previousIndex; &. =}g]
} Z"n'/S:q
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} q?Ku}eID3
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抽象业务类 BsK|:MM]
java代码: &ap`}^8pM
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/** 8>VI$
* Created on 2005-7-12 [Zt#
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*/ &J;H@d||
package com.javaeye.common.business; Cb
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import java.io.Serializable; <nw<v9Z
import java.util.List; s
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import org.hibernate.Criteria; )+w/\~@
import org.hibernate.HibernateException; WpJD=C%
import org.hibernate.Session; +Y5(hjE
import org.hibernate.criterion.DetachedCriteria; R?bn,T>
import org.hibernate.criterion.Projections; GcZM+ c
import l~fh_IV1
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org.springframework.orm.hibernate3.HibernateCallback; _z<Y#mik
import cVB|sYdf
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org.springframework.orm.hibernate3.support.HibernateDaoS ?@lx
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upport; |B%BwE
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import com.javaeye.common.util.PaginationSupport; y|e2j&m
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public abstract class AbstractManager extends dXhCyr%"6
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HibernateDaoSupport { Ox7uG{t$#
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privateboolean cacheQueries = false; Q/QQ:t<XUi
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privateString queryCacheRegion; VBbUl|X\
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publicvoid setCacheQueries(boolean u>,lf\Fgz
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cacheQueries){ y$j1?7
this.cacheQueries = cacheQueries; 5:*5j@/S
} :cXIO
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publicvoid setQueryCacheRegion(String 8S.')<-f
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queryCacheRegion){ C(F1VS
this.queryCacheRegion = 8/Et&TJ`
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queryCacheRegion; uQ:ut(
} VD9
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publicvoid save(finalObject entity){ I" 8d5a}
getHibernateTemplate().save(entity); j<l#qho{h
} 0NL :z1N-h
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publicvoid persist(finalObject entity){ E6'8Zb
getHibernateTemplate().save(entity); 3AdP^B<
} x1 ;rb8
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publicvoid update(finalObject entity){ @9_nwf~X4
getHibernateTemplate().update(entity); q4sl=`L5Sp
} lSn5=^]q
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publicvoid delete(finalObject entity){ 3E<aiGU
getHibernateTemplate().delete(entity); d3EjI6R*z
}
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publicObject load(finalClass entity, _L*f8e8
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finalSerializable id){ Y)'!'J
return getHibernateTemplate().load gq
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(entity, id); 9"WRI Ht'c
} y0scL7/
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publicObject get(finalClass entity, `j"4:
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finalSerializable id){ z6p#fsD
return getHibernateTemplate().get -]Q3/"Q
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(entity, id); ltNuLZ
} DapQ}2'_
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publicList findAll(finalClass entity){ .HyjL5r-
return getHibernateTemplate().find("from }Q`/K;yq
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" + entity.getName()); v$t{o{3
} |9+bSH9
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publicList findByNamedQuery(finalString >lA7*nn
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namedQuery){ jv*Dg (
return getHibernateTemplate pZu?V"R
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().findByNamedQuery(namedQuery); IM[54_I
} AU0$A403
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publicList findByNamedQuery(finalString query, ZvUp#8x(3
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finalObject parameter){ |d~B]65t
return getHibernateTemplate d>YmKTk"
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().findByNamedQuery(query, parameter); &\&'L|0F
} GMEw
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publicList findByNamedQuery(finalString query, U^B"|lc:[
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finalObject[] parameters){ $TR=3[j
return getHibernateTemplate :L]-'\y
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().findByNamedQuery(query, parameters); :0B
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} |$M@09,F"
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publicList find(finalString query){ HvAE,0N
return getHibernateTemplate().find 2y^Uk,g
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(query); $b4*/vMr
} cE^kpnVq|<
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publicList find(finalString query, finalObject cL?\^K)
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parameter){ U%Dit
return getHibernateTemplate().find {*sGhGwr
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(query, parameter); d
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} lrCm9Oy
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public PaginationSupport findPageByCriteria W5pn;u- sz
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(final DetachedCriteria detachedCriteria){ b([:,T7
return findPageByCriteria y^9bfMA
v,n);
(detachedCriteria, PaginationSupport.PAGESIZE, 0); S<V-ZV&_:U
} <BZ_ (H
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public PaginationSupport findPageByCriteria JK[T]|G
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(final DetachedCriteria detachedCriteria, finalint T]^?l
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startIndex){ dFzYOG1
return findPageByCriteria T&]Na
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(detachedCriteria, PaginationSupport.PAGESIZE, ol50d73B
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startIndex); B@d1xjp)']
} SK?I.
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public PaginationSupport findPageByCriteria (m6EQoW^s+
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(final DetachedCriteria detachedCriteria, finalint Umij!=GPG^
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pageSize, # ?_#!T|
finalint startIndex){ nQ|GqU\oA
return(PaginationSupport) V)=Z6 ti
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getHibernateTemplate().execute(new HibernateCallback(){ Xj%,xm>}!u
publicObject doInHibernate 5Wo5n7o
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(Session session)throws HibernateException { g#w`J\iz
Criteria criteria = ;"D~W#0-v
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detachedCriteria.getExecutableCriteria(session); C B6A}m
int totalCount = >$Fp}?xX
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((Integer) criteria.setProjection(Projections.rowCount { E^U6@
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()).uniqueResult()).intValue(); sp^Wo7&g
criteria.setProjection 5lGQ#r
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(null); ,'u *ZB;
List items = >G&^?5
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criteria.setFirstResult(startIndex).setMaxResults Z4#v~!
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(pageSize).list(); Y|_O8[
PaginationSupport ps = ]Y{,N x
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new PaginationSupport(items, totalCount, pageSize, Z/gsCYS3F
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startIndex); N\'TR6_,b
return ps; Yc|uD-y
} 7_KXD#
}, true); *U_S1>0n
} =PZWS&(L
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public List findAllByCriteria(final {tc57jsr
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DetachedCriteria detachedCriteria){ PYu$1o9+N
return(List) getHibernateTemplate a_MFQf&KV
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().execute(new HibernateCallback(){ <*_o0;h|
publicObject doInHibernate d+0^u(gc!8
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(Session session)throws HibernateException { +mLD/gK`
Criteria criteria = 7k'gt/#up
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detachedCriteria.getExecutableCriteria(session); _KN:
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return criteria.list(); Ev{MCu1!6
} ]
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}, true); &atyDFJ'
} Q(e{~
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public int getCountByCriteria(final D#ZPq,f
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DetachedCriteria detachedCriteria){ -x{&an=
Integer count = (Integer) 6A?8tm/0
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getHibernateTemplate().execute(new HibernateCallback(){ ]+ZM/'X
publicObject doInHibernate hl<y4y&|
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(Session session)throws HibernateException { xG1?F_]
Criteria criteria = I|T7+{5z
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detachedCriteria.getExecutableCriteria(session); lm*g Gy1i
return 2T?TM! \Q
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criteria.setProjection(Projections.rowCount WL1\y|
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()).uniqueResult(); m]P/if7
} NH4?q!'G
}, true); /tZ0
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return count.intValue(); ot }6D
} -=mwy
} ,56;4)cv
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用户在web层构造查询条件detachedCriteria,和可选的 O:YJ%;w
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 'Wp@b678
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PaginationSupport的实例ps。 y\,f6=%k
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ps.getItems()得到已分页好的结果集 $8g42LR'
ps.getIndexes()得到分页索引的数组 [0!{_E)<
ps.getTotalCount()得到总结果数 :c:V%0Yji
ps.getStartIndex()当前分页索引 .&|L|q}
ps.getNextIndex()下一页索引 WFDCPQ@
ps.getPreviousIndex()上一页索引 7&|6KN}c
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 V|: qow:F
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,尤其是上面的示例代码,让我着实觉得该对我原来的分页查询做 F#|Z# Mu
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一下代码重构了。 iRve)
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我把原本我的做法也提供出来供大家讨论吧: X 8R1a?
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首先,为了实现分页查询,我封装了一个Page类: (a#pvEY
java代码: 0Oap39
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/*Created on 2005-4-14*/ =/}X$,@2
package org.flyware.util.page; 5@f5S0 Y
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/** T6HU*(
* @author Joa H~Uq?!=b
* wOg,SMiq
*/ %{'4.
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publicclass Page { qqvF-mDN
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/** imply if the page has previous page */ ir&.Z5=
privateboolean hasPrePage; #jP/k.
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/** imply if the page has next page */ L~&" aF/b
privateboolean hasNextPage; zy>}L #
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/** the number of every page */ (0C&z/
privateint everyPage; 8xTix1u0
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/** the total page number */ V^rW?Do
privateint totalPage; 8zmv
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/** the number of current page */ rQj~[Y.c
privateint currentPage; 1exfCm
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/** the begin index of the records by the current $$4W}Ug3U
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query */ '5rUe\k
privateint beginIndex; 9o_-=>(
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/** The default constructor */ '[fZt#
public Page(){ ~L'nzquF
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} ZqK]jT6V/X
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/** construct the page by everyPage E474l
* @param everyPage l RND
* */ R|Y~u* D
public Page(int everyPage){ 8&.-]{Z
this.everyPage = everyPage; JXm?2/
} XeU<^ [
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/** The whole constructor */ tlGWl0V?7Q
public Page(boolean hasPrePage, boolean hasNextPage, w~N-W8xNR
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int everyPage, int totalPage, &yLc1#H
int currentPage, int beginIndex){ @]?R2bI
this.hasPrePage = hasPrePage; aU(tu2
this.hasNextPage = hasNextPage; H.~bD[gA
this.everyPage = everyPage; 3_zSp.E\l
this.totalPage = totalPage; D9o*8h2$
this.currentPage = currentPage; :Tb7r6
this.beginIndex = beginIndex; _6rKC*Pe1
} bU+9Gi@v
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/** M&[b.t*
* @return H\+-cvl
* Returns the beginIndex. * nCx[
*/ 9L HuS
publicint getBeginIndex(){ Tz` ,{k
return beginIndex; tcOnM w
} v}P!HczmMP
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/** N-QCfDao
* @param beginIndex `~nCbUUee
* The beginIndex to set.
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*/ 61:9(*4~!F
publicvoid setBeginIndex(int beginIndex){ C3.=GRg~l
this.beginIndex = beginIndex; hdg<bZk:
} v[L[A3`"/
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/** 6"%2,`Nu
* @return Q52bh'cuU
* Returns the currentPage. kzi|$Gs<