Hibernate3 提供了DetachedCriteria,使得我们可以在Web层构造 |;m`874
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detachedCriteria,然后调用业务层Bean,进行动态条件查询,根 H&Y{jqua
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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 >-5Gt
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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 M6iO8vY
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分页支持类: k5;Vl0Ho
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java代码: xf"5<PTW</
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package com.javaeye.common.util; uoY`qF.`
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import java.util.List; 3u0<v%Qi
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publicclass PaginationSupport { Tb1}XvZ
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publicfinalstaticint PAGESIZE = 30; fb.\V]K
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privateint pageSize = PAGESIZE; I,4-
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privateList items; 27E9NO=
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privateint totalCount; b}Hl$V(uD
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privateint[] indexes = newint[0]; !H|82:`t+
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privateint startIndex = 0; 3E!<p
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public PaginationSupport(List items, int DxKfWb5 R
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totalCount){ LX\*4[0%K
setPageSize(PAGESIZE); b?]ly(
setTotalCount(totalCount); ,)rZAI
setItems(items); ?(/j<,m^
setStartIndex(0); mDF"&.(j
} $rpTs?j*K$
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public PaginationSupport(List items, int me:|!lI7YU
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totalCount, int startIndex){ Fb|e]?w
setPageSize(PAGESIZE); :x""E5H
setTotalCount(totalCount); x #tu
setItems(items); V(2j*2R!
setStartIndex(startIndex); p37zz4
} ,]uX:h-EM
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public PaginationSupport(List items, int !<=%;+
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totalCount, int pageSize, int startIndex){ ..q63dr
setPageSize(pageSize); Le`/
setTotalCount(totalCount); :qAc= IC%
setItems(items); =l8!VJa
setStartIndex(startIndex); 833%H`jQc
} uojh%@.4
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publicList getItems(){ 7O+Ij9+{n
return items; vdH+>l
} jKj=#O
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publicvoid setItems(List items){ t8AkdSU0
this.items = items; b@wBR9s
} C,{F0-D
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publicint getPageSize(){ pG!(6V-x<E
return pageSize; nrTv=*tDj
} 9P7xoXJ@y
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publicvoid setPageSize(int pageSize){ &N"'7bK6n
this.pageSize = pageSize; jB%"AvIX
} $AA~]'O>6:
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publicint getTotalCount(){ `y^zM/Ib
return totalCount; _oJ2]f6KX
} Dh&:-
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publicvoid setTotalCount(int totalCount){ }{&ln
if(totalCount > 0){ Bn~\HW\Lh
this.totalCount = totalCount;
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int count = totalCount / ,C{^`Bk-W
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pageSize; Mhe|eD#)
if(totalCount % pageSize > 0) (!ZQ
count++; Ig1lol:;
indexes = newint[count]; <H5n>3#pH
for(int i = 0; i < count; i++){ aJ:A%+1
indexes = pageSize * Xr?>uqY!M
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} cxXbo a
}else{ W!/vm
this.totalCount = 0; L289'Gzg
} U@.u-)oX
} I!fB1aq-
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publicint[] getIndexes(){ lo+xo;Nd
return indexes; `E3:;|
} x7"z(rKl
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publicvoid setIndexes(int[] indexes){ (TEo_BW|+
this.indexes = indexes; 87^:<\pp
} \npz.g^c_
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publicint getStartIndex(){ ;".z[l *
return startIndex; klgv{_b
} n$.1Wk"
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publicvoid setStartIndex(int startIndex){ l^k+E-w\
if(totalCount <= 0) Mjb 1
this.startIndex = 0; p`>AnfG
elseif(startIndex >= totalCount) 3<c*v/L{C\
this.startIndex = indexes m_Mwg
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[indexes.length - 1]; Y 3o^Euou
elseif(startIndex < 0) +w "XNl
this.startIndex = 0; 2Sge
else{ pO"m~ mpA
this.startIndex = indexes R{*_1cyW
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[startIndex / pageSize]; C/F@ ]_y
} L)q`D2|'
} r2RBrZ@1
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publicint getNextIndex(){ a*Rz<08
int nextIndex = getStartIndex() + Ns'FH(:
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pageSize; +x(YG(5\w
if(nextIndex >= totalCount) aSRjFL^
return getStartIndex(); gf+o1\5t@
else F?7u~b|@{
return nextIndex; Q"A_bdg5
} j7f5|^/x3
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publicint getPreviousIndex(){ mHKJ
int previousIndex = getStartIndex() - t-_#Q bzE{
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pageSize; avlqDi1l
if(previousIndex < 0) F
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return0; R;WW
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else neF8V"-u&
return previousIndex; a;%I\w;2
} 5)w4)K-%
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} O47PkP8
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抽象业务类 > 84e`aGE
java代码: UanEzx%
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/** @9aGz6k+
* Created on 2005-7-12 h{I`7X
*/ gt'*B5F(
package com.javaeye.common.business; a_Jb>}
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import java.io.Serializable; GSP?X$E
import java.util.List; YNI;h%w
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import org.hibernate.Criteria; Y.7}
import org.hibernate.HibernateException; MZ WmlJ
import org.hibernate.Session; w^ 3|(F
import org.hibernate.criterion.DetachedCriteria; ?b56AE
import org.hibernate.criterion.Projections; 6.[)`iF+#
import ?H`j>]%&
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org.springframework.orm.hibernate3.HibernateCallback; vHS2q
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import guU=NQZ
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org.springframework.orm.hibernate3.support.HibernateDaoS #G[t X6gU
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upport; (Ux[[
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import com.javaeye.common.util.PaginationSupport; i0\)%H:z
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public abstract class AbstractManager extends mg` j[<wp
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HibernateDaoSupport { ;=a_B1"9u
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privateboolean cacheQueries = false; 44~hw:
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privateString queryCacheRegion; U9
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publicvoid setCacheQueries(boolean yplG18
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cacheQueries){ 0'`S,
this.cacheQueries = cacheQueries; 6lsEGe
} `"c'z;
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publicvoid setQueryCacheRegion(String %&h c"7/k
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queryCacheRegion){ n}JPYu
this.queryCacheRegion = 9Sz7\W0
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queryCacheRegion; LL.x11o3
} pw\P<9e=
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publicvoid save(finalObject entity){ >g]ON9CGH
getHibernateTemplate().save(entity); &<Zdyf?[Ou
} ~>g+2]Bn>$
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publicvoid persist(finalObject entity){ f}iU& 3S
getHibernateTemplate().save(entity); Bd&`Xfebj
} VO_dA4C}z
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publicvoid update(finalObject entity){ gfN2/TDC]P
getHibernateTemplate().update(entity); epkD*7
} R!6=7
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publicvoid delete(finalObject entity){ w"~<h;
getHibernateTemplate().delete(entity); \J3/keL
} u%B&WwHG
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publicObject load(finalClass entity, =ewy Q
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finalSerializable id){ JYJU&u
return getHibernateTemplate().load ~x#vZ=]8
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(entity, id); Xb,T{.3@
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publicObject get(finalClass entity, Q|c|2byb
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finalSerializable id){ VD[pZ2;4
return getHibernateTemplate().get v+6e;xl8
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(entity, id); orqJ[!u)`
} y'
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publicList findAll(finalClass entity){ ||Y<f *
return getHibernateTemplate().find("from ~=cmM
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" + entity.getName()); S-c ^eLzQ
} }`_(<H
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publicList findByNamedQuery(finalString >;9NtoE
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namedQuery){ t,<UohL|z
return getHibernateTemplate 5JSrrpGr
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().findByNamedQuery(namedQuery); :FHA]oec1
} X{Zm9T
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publicList findByNamedQuery(finalString query, ue\t ,*KYd
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finalObject parameter){ Fe!9y2Mg
return getHibernateTemplate fzPZ|
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().findByNamedQuery(query, parameter); JvL{| KtyU
} Cy@ cLdV
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publicList findByNamedQuery(finalString query, *eb-rhCVn
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finalObject[] parameters){ yWb4Ify
return getHibernateTemplate rQr!R$t/[
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().findByNamedQuery(query, parameters); Z
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} 3CZS)
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publicList find(finalString query){ uM S*(L_
return getHibernateTemplate().find {/ 2E*|W~I
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(query); y{=>$C[
} (CE7j<j
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publicList find(finalString query, finalObject t'(1I|7
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parameter){ -LWK*q[J;*
return getHibernateTemplate().find +B"0{>n}F
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(query, parameter); $NG++N
} Mvcfk$pA
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public PaginationSupport findPageByCriteria Or+p%K}-7
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(final DetachedCriteria detachedCriteria){ &JhX+'U
return findPageByCriteria -t-tn22
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(detachedCriteria, PaginationSupport.PAGESIZE, 0); =.Tv)/ea
} lFq{O;q7}
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public PaginationSupport findPageByCriteria bw S*]!*
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(final DetachedCriteria detachedCriteria, finalint ;rHO&(h-
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startIndex){ ^jSsa
return findPageByCriteria 8@\7&C(g17
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(detachedCriteria, PaginationSupport.PAGESIZE, qoX@@xr1
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startIndex); <02m%rhuW
} qJv[MBjk3B
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public PaginationSupport findPageByCriteria eJ@~o{,?>
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(final DetachedCriteria detachedCriteria, finalint K=\O5#F?3
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pageSize, "484n/D
finalint startIndex){ 7Y( 5]A9=
return(PaginationSupport) Ng=ONh
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getHibernateTemplate().execute(new HibernateCallback(){ 9A$m$
publicObject doInHibernate KZ:hKY@q
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(Session session)throws HibernateException { %,q.),F
Criteria criteria = anN#5jt
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detachedCriteria.getExecutableCriteria(session); #x@ eDnb_
int totalCount = =Lp7{09u
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((Integer) criteria.setProjection(Projections.rowCount q3w1GD
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()).uniqueResult()).intValue(); U1R4x!ym4
criteria.setProjection E6MA?Ax&=
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(null); elPE%'
List items = S::>N.y
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criteria.setFirstResult(startIndex).setMaxResults pdVQ*=c?M
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(pageSize).list(); qUJ
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PaginationSupport ps = p( LZ)7/
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new PaginationSupport(items, totalCount, pageSize, Y]g?2N=E
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startIndex); ,xi({{L*
return ps; AC- )BM';
} Z;DCI-Wg
}, true); ,<Kx{+ [h
} 3iNkoBCg
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public List findAllByCriteria(final )%Iv[TB[
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DetachedCriteria detachedCriteria){ ^QXbJJ
return(List) getHibernateTemplate Dm0a.J v
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().execute(new HibernateCallback(){ Y3U9:VB
publicObject doInHibernate +cu^%CXT
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(Session session)throws HibernateException { zTm]AG|0
Criteria criteria = ^A_;#vK
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detachedCriteria.getExecutableCriteria(session); B4H!5b
return criteria.list(); g_.^O$}
} m_NCx]#e
}, true); EG<s_d?
} 8At<Wic
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public int getCountByCriteria(final 3lxc4@Zmd
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DetachedCriteria detachedCriteria){ 2f:^S/.A
Integer count = (Integer) evuZY X@
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getHibernateTemplate().execute(new HibernateCallback(){ Q[4:
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publicObject doInHibernate fxQN+6;
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(Session session)throws HibernateException {
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Criteria criteria = 3251Vq %
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detachedCriteria.getExecutableCriteria(session); ro~+j}*
return .?W5{U
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criteria.setProjection(Projections.rowCount JK_OZ
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()).uniqueResult(); dFXc/VH')
} $7Jo8^RE
}, true); }:Z9Vc ZP`
return count.intValue(); N_C;&hJN$w
} 9)dfL?x8V{
} $%k1fa C
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用户在web层构造查询条件detachedCriteria,和可选的 ^eq</5q D
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startIndex,调用业务bean的相应findByCriteria方法,返回一个 u'~;Y.@i'
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PaginationSupport的实例ps。 ~%k ?L4%
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ps.getItems()得到已分页好的结果集 X@2-*so<
ps.getIndexes()得到分页索引的数组 J;Rv ~<7
ps.getTotalCount()得到总结果数 pJIv+
ps.getStartIndex()当前分页索引 >h~IfZU1
ps.getNextIndex()下一页索引 `|Z}2vo;j
ps.getPreviousIndex()上一页索引 kma?v B
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连续看了两篇robbin有关DetachedCriteria的介绍,感觉真的不错 7L5P%zLtB
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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 \K2*Q&>
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一下代码重构了。 z9/G4^qF
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我把原本我的做法也提供出来供大家讨论吧: 9=l.T/?sf
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首先,为了实现分页查询,我封装了一个Page类: R[tC^]ai
java代码: l:|D,q
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/*Created on 2005-4-14*/ U\@A_
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package org.flyware.util.page; w*7|dZk{
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/** ;F:fM!l=
* @author Joa zt24qTKL
* k3!a$0Bs;
*/ /a9!Cf
publicclass Page { 1Nn@L2b 2
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/** imply if the page has previous page */ ;r\(p|e
privateboolean hasPrePage; Z4TL6]^R
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/** imply if the page has next page */ zk_Eb?mhwV
privateboolean hasNextPage; :Sg&0Wj+#j
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/** the number of every page */ ,$*IzL~
privateint everyPage; )EM7,xMz
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/** the total page number */ ,Z9>h[JF
privateint totalPage; iOw3MfO
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/** the number of current page */ W[bmzvJ_X
privateint currentPage; ;E;To\NCYF
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/** the begin index of the records by the current C2U~=q>>
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query */ &$FvWFRh#
privateint beginIndex; nv0@xnbz
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/** The default constructor */ JNI>VP[c
public Page(){ ?WI3/>:<
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} fN%jJ-[d
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/** construct the page by everyPage UM%o\BiO
* @param everyPage FjfN3#qlg
* */ 9W7#u}Z
public Page(int everyPage){ j|fd-<ng
this.everyPage = everyPage; le)DgIT>=
} 8ip7^
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